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13 pages, 677 KiB

Open AccessArticle

Four New Flavonoids Isolated from the Aerial Parts of Cadaba rotundifolia Forssk. (Qadab)

by Gadah Abdulaziz Al-Hamoud, Raha Saud Orfali, Sachiko Sugimoto, Yoshi Yamano, Nafee Alothyqi, Ali Mohammed Alzahrani and Katsuyoshi Matsunami

Molecules 2019, 24(11), 2167; https://doi.org/10.3390/molecules24112167 - 09 Jun 2019

Cited by 8 | Viewed by 3528

Abstract

Cadaba rotundifolia (Forssk.) (family: Capparaceae; common name: Qadab) is one of four species that grow in the Red Sea costal region in the Kingdom of Saudi Arabia. The roots and leaves of C. rotundifolia is traditionally used to treat tumors and abscesses in [...] Read more.

Cadaba rotundifolia (Forssk.) (family: Capparaceae; common name: Qadab) is one of four species that grow in the Red Sea costal region in the Kingdom of Saudi Arabia. The roots and leaves of C. rotundifolia is traditionally used to treat tumors and abscesses in Sudan. A previous phytochemical study of the roots yielded a quaternary alkaloid, but no report on chemical constituents of the aerial parts of the C. rotundifolia growing in Saudi Arabia has been issued so far. Oxidative stress and advanced glycation end products (AGEs) are thought as causal factors in many degenerative diseases, such as Alzheimer’s disease, diabetes, atherosclerosis and aging. In this study, a total of twenty compounds, including four previously undescribed acylated kaempferol glucosides, were isolated from the aerial parts of C. rotundifolia collected in Saudi Arabia. These new compounds were identified as kaempferol 3-O-[2-O-(trans-feruloyl)-3-O-β-d-glucopyranosyl]-β-d-glucopyranoside (1), kaempferol 3-O-β-neohesperidoside-7-O-[2-O-(cis-p-coumaroyl)-3-O-β-d-glucopyranosyl]-β-d-glucopyranoside (2), kaempferol 3-O-[2,6-di-O-α-l-rhamnopyranosyl]-β-d-glucopyranoside-7-O-[6-O-(trans-feruloyl)]-β-d-glucopyranoside (3) and kaempferol 3-O-[2,6-di-O-α-l-rhamnopyranosyl]-β-d-glucopyranoside-7-O-[6-O-(trans-p-coumaroyl)]-β-d-glucopyranoside (4). Their structures were established based on UV-visible, 1D, 2D NMR, and HR-ESI-MS analyses. Of the assayed compounds, 17 and 18 showed potent radical scavenging activity with IC₅₀ values of 14.5 and 11.7 µM, respectively, and inhibitory activity toward AGEs together with compound 7 with IC₅₀ values 96.5, 34.9 and 85.5 µM, respectively. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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18 pages, 3135 KiB

Open AccessArticle

Repression of Acetaminophen-Induced Hepatotoxicity in HepG2 Cells by Polyphenolic Compounds from Lauridia tetragona (L.f.) R.H. Archer

by Samuel Odeyemi and John Dewar

Molecules 2019, 24(11), 2118; https://doi.org/10.3390/molecules24112118 - 04 Jun 2019

Cited by 10 | Viewed by 4096

Abstract

Lauridia tetragona (L.f) R.H. Archer is routinely used in traditional medicine; however, its hepatoprotective property is yet to be scientifically proven. To this effect, the hepatoprotective activity of the polyphenolic-rich fractions (PPRFs) was investigated against acetaminophen (APAP) injured HepG2 cells. The ability of [...] Read more.

Lauridia tetragona (L.f) R.H. Archer is routinely used in traditional medicine; however, its hepatoprotective property is yet to be scientifically proven. To this effect, the hepatoprotective activity of the polyphenolic-rich fractions (PPRFs) was investigated against acetaminophen (APAP) injured HepG2 cells. The ability of the PPRF to scavenge free radicals was tested against 2,2-diphenyl-1-picrylhydrazyl (DPPH), and [2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonicacid)] (ABTS). The ferric ion reducing power (FRAP) was also evaluated as a cell-free antioxidant assay. The hepatoprotective activity was then investigated by observing the effect of PPRFs against APAP-induced reduction in cell viability of HepG2 cells. The concentrations of alanine aminotransferase (AST), aspartate aminotransferase (ALT) and lactate dehydrogenase (LDH) released into the medium were evaluated while the underlying mechanism was further explored through western blot analysis. Thereafter, the isolated PPRFs were identified using UHPLC-QToF-MS. All six fractions of the PPRFs isolated showed significant antioxidant properties that were evident by the effective scavenging of DPPH, ABTS, and higher FRAP. The results indicated that PPRF pretreatments ameliorated APAP-induced hepatocellular injury by significantly inhibiting the leakage of AST, ALT, and LDH into the medium. The most active fractions for hepatoprotection were PPRF4 and PPRF6 with IC₅₀ of 50.243 ± 8.03 and 154.59 ± 1.9 μg/mL, respectively. PPRFs markedly increased activities of liver superoxide dismutase, total antioxidant capacity, and liver glutathione concentration. Both PPRF4 and PPRF6 significantly increased the expression of Nrf2 and translocation. The LC-MS analysis revealed the presence of a wide variety of polyphenolics such as coumarin, ferulic acid, and caffeine among the dominant constituents. In conclusion, this study demonstrates that the isolated PPRFs have potential hepatoprotective activity that may be due to the increased expression of antioxidative genes dependent on Nrf2. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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10 pages, 596 KiB

Open AccessArticle

Insecticidal Activity of Four Lignans Isolated from Phryma leptostachya

by Yankai Li, Jiaqi Wei, Jiameng Fang, Wenbo Lv, Yufei Ji, Ahmed A.A. Aioub, Jiwen Zhang and Zhaonong Hu

Molecules 2019, 24(10), 1976; https://doi.org/10.3390/molecules24101976 - 22 May 2019

Cited by 15 | Viewed by 2933

Abstract

A new lignan (T4) and three known lignans (T1, T2, and T3) were isolated from the methanol extract of the roots of Phryma leptostachya using bioassay-guided method, and their structures were identified as phrymarolin I (T1 [...] Read more.

A new lignan (T4) and three known lignans (T1, T2, and T3) were isolated from the methanol extract of the roots of Phryma leptostachya using bioassay-guided method, and their structures were identified as phrymarolin I (T1), II (T2), haedoxan A (T3), and methyl 4-((6a-acetoxy-4-(6-methoxybenzo[d][1,3]dioxol-5-yl)tetrahydro-1H,3H-furo[3,4–c]furan-1-yl)oxy)-1-hydroxy-2,2-dimethoxy-5-oxocyclopent-3-ene-1-carboxylate (T4) byNMR and ESI-MS spectral data. Bioassay results revealed that haedoxan A exhibited remarkably high insecticidal activity against Mythimna separata with a stomach toxicity LC₅₀ value of 17.06 mg/L and a topical toxicity LC₅₀ value of 1123.14 mg/L at 24 h, respectively. Phrymarolin I and compound T4 also showed some stomach toxicity against M. separata with KD₅₀ values of 3450.21 mg/L at 4 h and 2807.10 mg/L at 8 h, respectively. In addition, phrymarolin I and haedoxan A exhibited some stomach toxicity against Plutella xylostella with an LC₅₀ value of 1432.05 and 857.28 mg/L at 48 h, respectively. In conclusion, this study demonstrated that lignans from P. leptostachya are promising as a novel class of insecticides or insecticide lead compounds for developing botanical pesticides. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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17 pages, 3670 KiB

Open AccessArticle

Antimicrobial, Antioxidant Activities, and HPLC Determination of the Major Components of Verbena carolina (Verbenaceae)

by Gonzalo Lara-Issasi, Cecilia Salgado, José Pedraza-Chaverri, Omar N. Medina-Campos, Agustín Morales, Marco A. Águila, Margarita Avilés, Blanca E. Rivero-Cruz, Víctor Navarro, Ramiro Ríos-Gómez and María Isabel Aguilar

Molecules 2019, 24(10), 1970; https://doi.org/10.3390/molecules24101970 - 22 May 2019

Cited by 10 | Viewed by 3832

Abstract

Verbena carolina L. (Verbenaceae) is used as a decoction in Mexican folk medicine with applications against digestive problems and for dermatological infections. The present work firstly reported HPLC analysis, as well as the free radical scavenging capacity of the extracts and isolated compounds. [...] Read more.

Verbena carolina L. (Verbenaceae) is used as a decoction in Mexican folk medicine with applications against digestive problems and for dermatological infections. The present work firstly reported HPLC analysis, as well as the free radical scavenging capacity of the extracts and isolated compounds. Antimicrobial analyses of these substances against the bacteria Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Salmonella typhi and the fungi Candida albicans, Trichophyton mentagrophytes and T. rubrum were also tested, as well as the acute oral toxicity in mice of aqueous extracts. Major secondary metabolites in V. carolina extracts were isolated by conventional phytochemical methods which consisted of three terpenoids ((1), (3) and (4)) and four phenolic compounds ((2), (4)–(6)). Their contents were determined by HPLC in six different samples from different locations. The results indicated that ursolic acid (1), hispidulin (2), verbenaline (3), hastatoside (4), verbascoside (5), hispidulin 7-O-β-d-glucuronopyranoside (6) and pectolinaringenin-7-O-α-d-glucuronopyranoside (7) were the main constituents and ranged from 0.17 to 3.37 mg/g of dried plant, with verbascoside being the most abundant and with a significant antioxidant activity in reactive oxygen species (ROS). Hispidulin was the only active compound against T. mentagrophytes and T. rubrum. The aqueous extract showed no significant toxicity (LD₅₀: > 5000 mg/mL). To our knowledge, this is the first comprehensive report of the chemical characterization of V. carolina and also of the activity of its constituents towards reactive oxygen species and dermatophytes, and its safety for consumption. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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12 pages, 1944 KiB

Open AccessArticle

Six New Methyl Apiofuranosides from the Bark of Phellodendron chinense Schneid and Their Inhibitory Effects on Nitric Oxide Production

by Peng-Fei Wang, Yan-Ping Li, Li-Qin Ding, Shi-Jie Cao, Li-Ning Wang and Feng Qiu

Molecules 2019, 24(10), 1851; https://doi.org/10.3390/molecules24101851 - 14 May 2019

Cited by 6 | Viewed by 2439

Abstract

A chemical investigation on 70% EtOH extract from the bark of Phellodendron chinense Schneid (Rutaceae) led to six new methyl apiofuranosides (1–6), and ten known compounds (7–16). All these compounds were characterized by the basic [...] Read more.

A chemical investigation on 70% EtOH extract from the bark of Phellodendron chinense Schneid (Rutaceae) led to six new methyl apiofuranosides (1–6), and ten known compounds (7–16). All these compounds were characterized by the basic analysis of the spectroscopic data including extensive 1D-, 2D-NMR (HSQC, HMBC), and high-resolution mass spectrometry, and the absolute configurations were determined by both empirical approaches and NOESY. Inhibitory effects of compounds 1–9 and 11–16 on nitric oxide production were investigated in lipopolysaccharide (LPS)-mediated RAW 264.7 cells, as a result, most of these isolates inhibited nitric oxide (NO) release, and among them 9, 11, and 12 displayed the strongest inhibition on NO release at the concentration of 12.5 μM. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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10 pages, 1476 KiB

Open AccessArticle

Bioassay-Guided Isolation of Triterpenoids as α-Glucosidase Inhibitors from Cirsium setosum

by Xiuting Li, Xiangjian Zhong, Xin Wang, Jinjie Li, Jiachen Liu, Kaiqi Wang, Jianyu Yue, Ximiao Yang, Xiaoya Shang and Sheng Lin

Molecules 2019, 24(10), 1844; https://doi.org/10.3390/molecules24101844 - 14 May 2019

Cited by 9 | Viewed by 3099

Abstract

Cirsium setosum (C. setosum) has a potential antihyperglycemic effect, but it is unclear what bioactive components play a key role. According to the α-glucosidase inhibition activity, three new taraxastane-type triterpenoids of 3β-hydroxy-30-hydroperoxy-20-taraxastene (1), 3β-hydroxy-22 [...] Read more.

Cirsium setosum (C. setosum) has a potential antihyperglycemic effect, but it is unclear what bioactive components play a key role. According to the α-glucosidase inhibition activity, three new taraxastane-type triterpenoids of 3β-hydroxy-30-hydroperoxy-20-taraxastene (1), 3β-hydroxy-22α-methoxy-20-taraxastene (2), and 30-nor-3β,22α-dihydroxy-20-taraxastene (3), as well as five known taraxastane triterpenoids of 3β,22-dihydroxy-20-taraxastene (4), 20-taraxastene-3,22-dione (5), 3β-acetoxy-20-taraxasten-22-one (6), 3β-hydroxy-20-taraxasten-22-one (7), and 30-nor-3β-hydroxy-20-taraxastene (8) were obtained from the petroleum ether-soluble portion of the ethanol extract from C. setosum. All chemical structures of the compounds were elucidated by spectroscopic data analysis and compared with literature data. Compounds 4–8 were identified for the first time from this plant, and compounds 1, 2, 4, and 7 exhibited more potent α-glucosidase inhibitory activity—with IC₅₀ values of 18.34 ± 1.27, 26.98 ± 0.89, 17.49 ± 1.42, and 22.67 ± 0.25 μM, respectively—than acarbose did (positive control, IC₅₀ 42.52 ± 0.32 μM). Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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18 pages, 665 KiB

Open AccessCommunication

Lanostane-Type Saponins from Vitaliana primuliflora

by Maciej Włodarczyk, Antoni Szumny and Michał Gleńsk

Molecules 2019, 24(8), 1606; https://doi.org/10.3390/molecules24081606 - 23 Apr 2019

Cited by 5 | Viewed by 2673

Abstract

The phytochemistry of the genera Androsace, Cortusa, Soldanella, and Vitaliana, belonging to the Primulaceae family is not well studied so far. Hence, in this paper, we present the results of UHPLC-MS/MS analysis of several primrose family members as well [...] Read more.

The phytochemistry of the genera Androsace, Cortusa, Soldanella, and Vitaliana, belonging to the Primulaceae family is not well studied so far. Hence, in this paper, we present the results of UHPLC-MS/MS analysis of several primrose family members as well as isolation and structure determination of two new saponins from Vitaliana primuliflora subsp. praetutiana. These two nor-triterpenoid saponins were characterized as (23S)-17α,23-epoxy-29-hydroxy-3β-[(O-β-d-glucopyranosyl-(1→2)-O-α-l-rhamnopyranosyl-(1→2)-O-β-d-glucopyranosyl-(1→2)-O-α-l-arabinopyranosyl-(1→6)-β-d-glucopyranosyl)oxy]-27-nor-lanost-8-en-25-one and (23S)-17α,23-epoxy-29-hydroxy-3β-[(O-α-l-rhamnopyranosyl-(1→2)-O-β-d-glucopyranosyl-(1→2)-O-α-l-arabinopyranosyl-(1→6)-β-d-glucopyranosyl)oxy]-27-nor-lanost-8-en-25-one, respectively. Their structures were determined by high resolution mass spectrometry (HRMS), tandem mass spectrometry (MS/MS), one- and two-dimensional nuclear magnetic resonance spectroscopy (1D-, and 2D-NMR) analyses. So far, the 27-nor-lanostane monodesmosides were rarely found in dicotyledon plants. Therefore their presence in Vitaliana and also in Androsace species belonging to the Aretia section is unique and reported here for the first time. Additionally, eleven other saponins were determined by HRMS and MS/MS spectra. The isolated lanostane saponins can be considered as chemotaxonomic markers of the family Primulaceae. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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13 pages, 2342 KiB

Open AccessArticle

Flavonoid Glycosides from Endemic Bulgarian Astragalus aitosensis (Ivanisch.)

by Hristo Vasilev, Samir Ross, Karel Šmejkal, Petr Maršík, Dagmar Jankovská, Jaroslav Havlík and Ondřej Veselý

Molecules 2019, 24(7), 1419; https://doi.org/10.3390/molecules24071419 - 11 Apr 2019

Cited by 6 | Viewed by 4454

Abstract

Astragalus is a very interesting plant genus, well-known for its content of flavonoids, triterpenes and polysaccharides. Its secondary metabolites are described as biologically active compounds showing several activities, e.g., immunomodulating, antibacterial, antiviral and hepatoprotective. This inspired us to analyze the Bulgarian endemic A. [...] Read more.

Astragalus is a very interesting plant genus, well-known for its content of flavonoids, triterpenes and polysaccharides. Its secondary metabolites are described as biologically active compounds showing several activities, e.g., immunomodulating, antibacterial, antiviral and hepatoprotective. This inspired us to analyze the Bulgarian endemic A. aitosensis (Ivanisch.) to obtain deeper information about its phenolic components. We used extensive chromatographic separation of A. aitosensis extract to obtain seven phenolic compounds (1–7), which were identified using combined LC-MS and NMR spectral studies. The 1D and 2D NMR analyses and HR-MS allowed us to resolve the structures of known compounds 5–7 as isorhamnetin-3-O-robinobioside, isorhamnetin-3-O-(2,6-di-O-α-rhamno-pyranosyl-β-galactopyranoside), and alangiflavoside, respectively, and further comparison of these spectral data with available literature helped us with structural analysis of newly described flavonoid glycosides 1–4. These were described in plant source for the first time. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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13 pages, 809 KiB

Open AccessArticle

New Dammarane-Type Saponins from Gynostemma pentaphyllum

by Po-Yen Chen, Chih-Chao Chang, Hui-Chi Huang, Li-Jie Zhang, Chia-Ching Liaw, Yu-Chi Lin, Nham-Linh Nguyen, Thanh-Hoa Vo, Yung-Yi Cheng, Susan L. Morris-Natschke, Kuo-Hsiung Lee and Yao-Haur Kuo

Molecules 2019, 24(7), 1375; https://doi.org/10.3390/molecules24071375 - 08 Apr 2019

Cited by 12 | Viewed by 4474

Abstract

Six new dammarane-type saponins, gypenosides CP1-6 (1–6), along with 19 known compounds 7–25, were isolated and characterized from the aerial parts of Gynostemma pentaphyllum. Among these compounds, eight dammarane-type saponins, 2, 5, 6 [...] Read more.

Six new dammarane-type saponins, gypenosides CP1-6 (1–6), along with 19 known compounds 7–25, were isolated and characterized from the aerial parts of Gynostemma pentaphyllum. Among these compounds, eight dammarane-type saponins, 2, 5, 6, 7, 11, 12, 13, and 15, exhibited the greatest antiproliferative effects against two human tumor cell lines (A549 and HepG2). Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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15 pages, 636 KiB

Open AccessArticle

Isolation and Purification of Bioactive Compounds from the Stem Bark of Jatropha podagrica

by Truong Ngoc Minh, Tran Dang Xuan, Hoang-Dung Tran, Truong Mai Van, Yusuf Andriana, Tran Dang Khanh, Nguyen Van Quan and Ateeque Ahmad

Molecules 2019, 24(5), 889; https://doi.org/10.3390/molecules24050889 - 03 Mar 2019

Cited by 37 | Viewed by 6158

Abstract

This paper reports the successive isolation and purification of bioactive compounds from the stem bark of Jatropha podagrica, a widely known medicinal plant. The ethyl acetate extract of the stem bark exhibited the strongest antioxidant activity assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) [...] Read more.

This paper reports the successive isolation and purification of bioactive compounds from the stem bark of Jatropha podagrica, a widely known medicinal plant. The ethyl acetate extract of the stem bark exhibited the strongest antioxidant activity assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, and ferric reducing antioxidant power (FRAP) assays (IC₅₀ = 46.7, 66.0, and 492.6, respectively). By column chromatography (CC) with elution of hexane and ethyl acetate at 8:2, 7:3, and 6:4 ratios, the isolation of this active extract yielded five fractions (C1–C5). Chemical structures of the constituents included in C1–C5 were elucidated by gas chromatography-mass spectrometry (GC-MS), electrospray ionization-mass spectrometry (ESI-MS), and nuclear magnetic resonance (NMR) and resolved as methyl gallate (C1, C2, C3, C4), gallic acid (C1, C2), fraxetin (C2, C3, C4, C5), and tomentin (C3). Mixture C2 (IC₅₀ DPPH and ABTS = 2.5 µg/mL) and C3 (IC₅₀ FRAP = 381 µg/mL) showed the highest antioxidant properties. Among the isolated fractions, C4 was the most potential agent in growth inhibition of six bacterial strains including Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Listeria monocytogenes, Bacillus subtilis, and Proteus mirabilis (MIC = 5, 20, 30, 20, 25, and 20 mg/mL, respectively). All identified constituents exerted an inhibitory activity on the growth of Lactuca sativa, of which the mixture C3 performed the maximal inhibition on shoot (IC₅₀ = 49.4 µg/mL) and root (IC₅₀ = 47.1 µg/mL) growth. Findings of this study suggest that gallic acid, methyl gallate, fraxetin, and tomentin isolated from J. podagrica possessed antioxidant, antibacterial, and growth inhibitory potentials. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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9 pages, 1082 KiB

Open AccessArticle

Novel Substituted Thiophenes and Sulf-Polyacetylene Ester from Echinops ritro L.

by Liang-Bo Li, Guang-Da Xiao, Wei Xiang, Xing Yang, Ke-Xin Cao and Rong-Shao Huang

Molecules 2019, 24(4), 805; https://doi.org/10.3390/molecules24040805 - 22 Feb 2019

Cited by 12 | Viewed by 3535

Abstract

Three new substituted bithiophenes (1–3), and one new sulf-polyacetylene ester, ritroyne A (16) were isolated from the whole plant of Echinops ritro together with twelve known substituted thiophenes. The structures were elucidated on the basis of extensive [...] Read more.

Three new substituted bithiophenes (1–3), and one new sulf-polyacetylene ester, ritroyne A (16) were isolated from the whole plant of Echinops ritro together with twelve known substituted thiophenes. The structures were elucidated on the basis of extensive spectroscopic analysis including 1D and 2D NMR as well as MS. Furthermore, the absolute configuration of ritroyne A (16) was established by computational methods. In bioscreening experiments, four compounds (2, 4, 12, 14) showed similar antibacterial activity against Staphylococcus aureus ATCC 2592 with levofloxacin (8 µg/mL). Five compounds (2, 4, 9, 12, 14) exhibited antibacterial activities against Escherichia coli ATCC 25922, with minimum inhibitory concentration (MIC) values of 32–64 µg/mL. Three compounds (2, 4, 12) exhibited antifungal activities against Candida albicans ATCC 2002 with MIC values of 32–64 µg/mL. However, compound 16 did not exhibit antimicrobial activities against three microorganisms. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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16 pages, 1397 KiB

Open AccessArticle

Acylated Flavonoid Glycosides are the Main Pigments that Determine the Flower Colour of the Brazilian Native Tree Tibouchina pulchra (Cham.) Cogn.

by Fernanda Mendes Rezende, Marcelo José Pena Ferreira, Mads Hartvig Clausen, Magdalena Rossi and Claudia Maria Furlan

Molecules 2019, 24(4), 718; https://doi.org/10.3390/molecules24040718 - 16 Feb 2019

Cited by 29 | Viewed by 4464

Abstract

Tibouchina pulchra (Cham.) Cogn. is a plant native to Brazil whose genus and family (Melastomataceae) are poorly studied with regards to its metabolite profile. Phenolic pigments of pink flowers were studied by ultra-performance liquid chromatography with a photodiode array detector and electrospray ionization [...] Read more.

Tibouchina pulchra (Cham.) Cogn. is a plant native to Brazil whose genus and family (Melastomataceae) are poorly studied with regards to its metabolite profile. Phenolic pigments of pink flowers were studied by ultra-performance liquid chromatography with a photodiode array detector and electrospray ionization quadrupole time-of-flight mass spectrometry. Therein, twenty-three flavonoids were identified with eight flavonols isolated by preparative high-performance liquid chromatography and analysed by one- and two-dimensional nuclear magnetic resonance. Kaempferol derivatives were the main flavonols, encompassing almost half of the detected compounds with different substitution patterns, such as glucoside, pentosides, galloyl-glucoside, p-coumaroyl-glucoside, and glucuronide. Concerning the anthocyanins, petunidin p-coumaroyl-hexoside acetylpentoside and malvidin p-coumaroyl-hexoside acetylpentoside were identified and agreed with previous reports on acylated anthocyanins from Melastomataceae. A new kaempferol glucoside was identified as kaempferol-(2′′-O-methyl)-4′-O-α-d-glucopyranoside. Moreover, twelve compounds were described for the first time in the genus with five being new to the family, contributing to the chemical characterisation of these taxa. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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8 pages, 716 KiB

Open AccessArticle

Gastroprotection of Calein D against Ethanol-Induced Gastric Lesions in Mice: Role of Prostaglandins, Nitric Oxide and Sulfhydryls

by María Elena Sánchez-Mendoza, Yaraset López-Lorenzo, Leticia Cruz-Antonio, Audifás-Salvador Matus-Meza, Yolanda Sánchez-Mendoza and Jesús Arrieta

Molecules 2019, 24(3), 622; https://doi.org/10.3390/molecules24030622 - 11 Feb 2019

Cited by 22 | Viewed by 3300

Abstract

Peptic ulcers are currently treated with various drugs, all having serious side effects. The aim of this study was to evaluate the gastroprotective activity of calein D (from Calea urticifolia), a sesquiterpene lactone with a germacrane skeleton. Gastric lesions were induced in [...] Read more.

Peptic ulcers are currently treated with various drugs, all having serious side effects. The aim of this study was to evaluate the gastroprotective activity of calein D (from Calea urticifolia), a sesquiterpene lactone with a germacrane skeleton. Gastric lesions were induced in mice by administering ethanol (0.2 mL) after oral treatment with calein D at 3, 10 and 30 mg/kg, resulting in 13.15 ± 3.44%, 77.65 ± 7.38% and 95.76 ± 2.18% gastroprotection, respectively, to be compared with that of the control group. The effect found for 30 mg/kg of calein D was not reversed by pretreatment with N^G-nitro-l-arginine methyl ester (l-NAME, 70 mg/kg, ip), indomethacin (10 mg/kg, sc) or N-ethylmaleimide (NEM, 10 mg/kg, sc). Hence, the mechanism of action of calein D does not involve NO, prostaglandins or sulfhydryl compounds. Calein D was more potent than carbenoxolone, the reference drug. The findings for the latter are in agreement with previous reports. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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7 pages, 719 KiB

Open AccessArticle

Three New 2-(2-Phenylethyl)chromone Derivatives of Agarwood Originated from Gyrinops salicifolia

by Wen-Hua Dong, Hao Wang, Feng-Juan Guo, Wen-Li Mei, Hui-Qin Chen, Fan-Dong Kong, Wei Li, Kai-Bing Zhou and Hao-Fu Dai

Molecules 2019, 24(3), 576; https://doi.org/10.3390/molecules24030576 - 06 Feb 2019

Cited by 12 | Viewed by 2764

Abstract

Two new 2-(2-phenylethyl)chromone derivatives (1–2), comprising 5,6,7,8-tetrahydro-2-(2-phenylethyl)chromone and benzylacetone moieties, together with one new 2-(2-phenylethenyl)chromone (3) were isolated from the ethyl acetate extraction of agarwood originated from Gyrinops salicifolia Ridl. All structures were unambiguously elucidated on the [...] Read more.

Two new 2-(2-phenylethyl)chromone derivatives (1–2), comprising 5,6,7,8-tetrahydro-2-(2-phenylethyl)chromone and benzylacetone moieties, together with one new 2-(2-phenylethenyl)chromone (3) were isolated from the ethyl acetate extraction of agarwood originated from Gyrinops salicifolia Ridl. All structures were unambiguously elucidated on the basis of 1D and 2D NMR spectra as well as by HRESIMS data. All isolated compounds were tested for acetylcholinesterase (AChE) inhibitory activity and cytotoxic activity against human myeloid leukemia cell line (K562). However, none of the compounds displayed AChE inhibitory activity at a concentration of 50 µg mL⁻¹ or cytotoxic activity against K562 cell line. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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12 pages, 857 KiB

Open AccessArticle

Phytochemical Analysis and Potential Biological Activities of Essential Oil from Rice Leaf

by Truong Ngoc Minh, Tran Dang Xuan, Truong Mai Van, Yusuf Andriana, Tran Duc Viet, Tran Dang Khanh and Hoang-Dung Tran

Molecules 2019, 24(3), 546; https://doi.org/10.3390/molecules24030546 - 02 Feb 2019

Cited by 10 | Viewed by 6736

Abstract

Although many investigations on phytochemicals in rice plant parts and root exudates have been conducted, information on the chemical profile of essential oil (EO) and potent biological activities has been limited. In this study, chemical compositions of rice leaf EO and in vitro [...] Read more.

Although many investigations on phytochemicals in rice plant parts and root exudates have been conducted, information on the chemical profile of essential oil (EO) and potent biological activities has been limited. In this study, chemical compositions of rice leaf EO and in vitro biological activities were investigated. From 1.5 kg of fresh rice leaves, an amount of 20 mg EO was obtained by distillation and analyzed by gas chromatography-mass spectrometry (GC-MS), electrospray ionization (ESI), and atmospheric pressure chemical ionization (APCI) to reveal the presence of twelve volatile constituents, of which methyl ricinoleate (27.86%) was the principal compound, followed by palmitic acid (17.34%), and linolenic acid (11.16%), while 2-pentadecanone was the least (2.13%). Two phytoalexin momilactones A and B were first time identified in EO using ultra-performance liquid chromatography coupled with electrospray mass spectrometry (UPLC/ESI-MS) (9.80 and 4.93 ng/g fresh weight, respectively), which accounted for 7.35% and 3.70% of the EO, respectively. The assays of DPPH (IC₅₀ = 73.1 µg/mL), ABTS (IC₅₀ = 198.3 µg/mL), FRAP (IC₅₀ = 700.8 µg/mL) and β-carotene oxidation (LPI = 79%) revealed that EO possessed an excellent antioxidant activity. The xanthine oxidase assay indicated that the anti-hyperuricemia potential was in a moderate level (IC₅₀ = 526 µg/mL) as compared with the standard allopurinol. The EO exerted potent inhibition on growth of Raphanus sativus, Lactuca sativa, and two noxious weeds Echinochloa crus-galli, and Bidens pilosa, but in contrast, the growth of rice seedlings was promoted. Among the examined plants, the growth of the E. crus-galli root was the most inhibited, proposing that constituents found in EO may have potential for the control of the problematic paddy weed E. crus-galli. It was found that the EO of rice leaves contained rich phytochemicals, which were potent in antioxidants and gout treatment, as well as weed management. Findings of this study highlighted the potential value of rice leaves, which may provide extra benefits for rice farmers. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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9 pages, 587 KiB

Open AccessArticle

Novel Cucurbitane Triterpenes from the Tubers of Hemsleya amabilis with Their Cytotoxic Acitivity

by Wei Feng, Yuan Zhou, Ling-Yu Zhou, Li-Ying Kang, Xiang Wang, Bao-Lin Li, Qing Li and Li-Ying Niu

Molecules 2019, 24(2), 331; https://doi.org/10.3390/molecules24020331 - 17 Jan 2019

Cited by 6 | Viewed by 2944

Abstract

Chemical research of the medicinal plant Hemsleya amabilis (Cucurbitaceae) yielded five new cucurbitane-type triterpenes hemslelis A–E (1–5) by silica gel column, ODS column, and semi-HPLC techniques. Their structures were determined by spectroscopic analysis and examined alongside existing data from [...] Read more.

Chemical research of the medicinal plant Hemsleya amabilis (Cucurbitaceae) yielded five new cucurbitane-type triterpenes hemslelis A–E (1–5) by silica gel column, ODS column, and semi-HPLC techniques. Their structures were determined by spectroscopic analysis and examined alongside existing data from prior studies. Compounds 1–5 were evaluated for their cytotoxic activities against three human tumor cell lines, Hela, HCT-8, and HepG-2, with the IC₅₀ ranging from 5.9 to 33.9 μM compared to Cisplatin. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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10 pages, 1206 KiB

Open AccessArticle

Triterpenes from the Mushroom Hypholoma lateritium: Isolation, Structure Determination and Investigation in Bdelloid Rotifer Assays

by Bayar Chuluunbaatar, Zoltán Béni, Miklós Dékány, Bernadett Kovács, András Sárközy, Zsolt Datki, Lilla Mácsai, János Kálmán, Judit Hohmann and Attila Ványolós

Molecules 2019, 24(2), 301; https://doi.org/10.3390/molecules24020301 - 15 Jan 2019

Cited by 10 | Viewed by 4741

Abstract

Twelve compounds (1–12) were isolated from the methanol extract of brick cap mushroom (Hypholoma lateritium (Schaeff.) P. Kumm.). The structures of the compounds were elucidated using extensive spectroscopic analyses, including NMR and MS measurements. Lanosta-7,9(11)-diene-12β,21α-epoxy-2α,3β,24β,25-tetraol (1) [...] Read more.

Twelve compounds (1–12) were isolated from the methanol extract of brick cap mushroom (Hypholoma lateritium (Schaeff.) P. Kumm.). The structures of the compounds were elucidated using extensive spectroscopic analyses, including NMR and MS measurements. Lanosta-7,9(11)-diene-12β,21α-epoxy-2α,3β,24β,25-tetraol (1) and 8-hydroxy-13-oxo-9E,11E-octa-decadienoic acid (2) were identified as new natural products, together with ten known compounds, from which 3β-hydroxyergosta-7,22-diene (4), demethylincisterol A2 (5), cerevisterol (6), 3β-O-glucopyranosyl-5,8-epidioxyergosta-6,22-diene (7), fasciculol E (9), and uridine (12) were identified in this species for the first time. The isolated triterpenes (1, 3–11) were investigated for their toxicity in vivo using bdelloid rotifer assays. Most of the examined steroids in general showed low toxicity, although the effects of the compounds varied in a wider range from the non-toxic lanosta-7,9(11)-diene-12β,21α-epoxy-2α,3β,24β,25-tetraol (1) to the significantly toxic cerevisterol (6), with substantial dependence in some cases on the presence of nutrient in the experimental environment. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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9 pages, 697 KiB

Open AccessCommunication

Antiproliferative and Enzyme Docking Analysis of Engleromycin from Engleromyces goetzei

by Yongli Zhang, Guilin Chen, Hong Ma and Mingquan Guo

Molecules 2019, 24(1), 166; https://doi.org/10.3390/molecules24010166 - 04 Jan 2019

Cited by 10 | Viewed by 3455

Abstract

Engleromyces goetzei P. Henn. (E. goetzei) has been widely used as a traditional herb for many years in Kenya due to its diverse biological effects. Although engleromycin was first isolated from E. goetzei in 1980, its pharmacological activity is still unknown. [...] Read more.

Engleromyces goetzei P. Henn. (E. goetzei) has been widely used as a traditional herb for many years in Kenya due to its diverse biological effects. Although engleromycin was first isolated from E. goetzei in 1980, its pharmacological activity is still unknown. In this study, engleromycin from E. goetzei was identified by spectroscopic analyses, and subsequently examined for its antiproliferative activity using human cancer cell lines of SGC-7901, HT-29, HeLa and A549. As a result, it was revealed that engleromycin strongly inhibited the growth of SGC-7901, HT-29, HeLa and A549 cells with IC₅₀ values at 26.77 ± 1.69 µM, 7.73 ± 0.18 µM, 7.00 ± 0.12 µM and 3.14 ± 0.03 µM, respectively. The results of topoisomerase II (Top II) inhibition assay in vitro implied that engleromycin might be a Top II inhibitor. Further insights into the potential mechanism of antiproliferative activity displayed that engleromycin could dock into the binding pockets of Top II, like the clinical inhibitor doxorubicin, and then inhibit the biological activity of Top II. Taken together, our findings suggest that engleromycin has an anticancer potential, and may serve as a leading compound for the development of antitumor agents. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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11 pages, 1827 KiB

Open AccessArticle

Cytotoxic Effects of Compounds Isolated from Ricinodendron heudelotii

by Omolara F. Yakubu, Abiodun H. Adebayo, Titilope M. Dokunmu, Ying-Jun Zhang and Emeka E.J. Iweala

Molecules 2019, 24(1), 145; https://doi.org/10.3390/molecules24010145 - 02 Jan 2019

Cited by 13 | Viewed by 4491

Abstract

This study was designed to explore the in vitro anticancer effects of the bioactive compounds isolated from Ricinodendron heudelotii on selected cancer cell lines. The leaves of the plant were extracted with ethanol and partitioned in sequence with petroleum ether, ethyl acetate, and [...] Read more.

This study was designed to explore the in vitro anticancer effects of the bioactive compounds isolated from Ricinodendron heudelotii on selected cancer cell lines. The leaves of the plant were extracted with ethanol and partitioned in sequence with petroleum ether, ethyl acetate, and n-butanol. The ethyl acetate fraction was phytochemically studied using thin layer chromatography (TLC) and column chromatography (CC). Structural elucidation of pure compounds obtained from the ethyl acetate fraction was done using mass spectra, ¹H-NMR, and ¹³C-NMR analysis. The isolated compounds were subsequently screened using five different cancer cell lines: HL-60, SMMC-7721, A-549, MCF-7, SW-480, and normal lung epithelial cell line, BEAS-2B, to assess their cytotoxic effects. Nine compounds were isolated and structurally elucidated as gallic acid, gallic acid ethyl ester, corilagin, quercetin-3-O-rhamnoside, myricetin-3-O-rhamnoside, 1,4,6-tri-O-galloyl glucose, 3,4,6-tri-O-galloyl glucose, 1,2,6-tri-O-galloyl glucose, and 4,6-di-O-galloyl glucose. Corilagin exhibited the most cytotoxic activity with an IC₅₀ value of 33.18 μg/mL against MCF-7 cells, which were comparable to cisplatin with an IC₅₀ value of 27.43 µg/mL. The result suggests that corilagin isolated from R. heudelotii has the potential to be developed as an effective therapeutic agent against the growth of breast cancer cells. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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12 pages, 2395 KiB

Open AccessArticle

Bioactivity-Guided Purification of Novel Herbal Antioxidant and Anti-NO Compounds from Euonymus laxiflorus Champ.

by Van Bon Nguyen, San-Lang Wang, Anh Dzung Nguyen, Zhi-Hu Lin, Chien Thang Doan, Thi Ngoc Tran, Hung Tse Huang and Yao-Haur Kuo

Molecules 2019, 24(1), 120; https://doi.org/10.3390/molecules24010120 - 30 Dec 2018

Cited by 13 | Viewed by 3587

Abstract

Euonymus laxiflorus Champ., a medicinal herb collected in Vietnam, has been reported to show several potent bioactivities, including anti-NO, enzyme inhibition, hypoglycemic and antidiabetic effects. Recently, the antioxidant activity of Euonymus laxiflorus Champ. trunk bark (ELCTB) has also been reported. However, the active [...] Read more.

Euonymus laxiflorus Champ., a medicinal herb collected in Vietnam, has been reported to show several potent bioactivities, including anti-NO, enzyme inhibition, hypoglycemic and antidiabetic effects. Recently, the antioxidant activity of Euonymus laxiflorus Champ. trunk bark (ELCTB) has also been reported. However, the active antioxidant and anti-NO constituents existing in ELCTB have not been reported in the literature. The objective of this study was to purify the active antioxidants from ELCTB and investigate the anti-NO effect of the major constituents. Twenty-two phenolics isolated from ELCTB, including 12 compounds newly isolated in this study (1–12) and 10 constituents obtained from our previous work, were evaluated for their antioxidant activity. Of these, 12 compounds (4–6, 9, 13–15, 18–22) showed a potent antioxidant capacity (FRS50 = 7.8–58.11 µg/mL), in comparison to α-tocopherol (FRS50 = 23 µg/mL). In the anti-NO activity tests, Walterolactone A (1a) and B (1b) β-d-glucopyranoside (13) demonstrated the most effective and comparable activity to that of quercetin with max inhibition and IC₅₀ values of 100%, 1.3 µg/mL, and 100%, 1.21 µg/mL, respectively. The crude extract and its major compounds showed no cytotoxicity on normal cells. Notably, three constituents (9, 11, and 12) were identified as new compounds, another three constituents, including 1, 7, and 8, were found to be new natural products, constituents 9 and 13 were determined to be new antioxidants, and compound 13 was reported to have novel potent anti-NO activity for the first time. The results of this study contribute to the enrichment of new natural products and compounds, as well as the novel biological activity of constituents isolated from Euonymus laxiflorus Champ. The current study also indicates ELCTB as a rich natural source of active phenolics. It is suggested that ELCTB could be developed as a health food with promising antioxidant and anti-NO effects, as well as other beneficial biological activities. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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12 pages, 1333 KiB

Open AccessArticle

Cycloartane and Oleanane Glycosides from the Tubers of Eranthis cilicica

by Kazuki Watanabe, Yoshihiro Mimaki, Haruhiko Fukaya and Yukiko Matsuo

Molecules 2019, 24(1), 69; https://doi.org/10.3390/molecules24010069 - 25 Dec 2018

Cited by 10 | Viewed by 2961

Abstract

Phytochemical analysis of the tubers of Eranthis cilicica was performed as part of our continuous study on the plants of the family Ranunculaceae, which resulted in the isolation of eleven new cycloartane glycosides (1–11) and one new oleanane [...] Read more.

Phytochemical analysis of the tubers of Eranthis cilicica was performed as part of our continuous study on the plants of the family Ranunculaceae, which resulted in the isolation of eleven new cycloartane glycosides (1–11) and one new oleanane glycoside (13), together with one known oleanane glycoside (12). The structures of the new compounds were determined by extensive spectroscopic analysis, including two-dimensional (2D) NMR, and enzymatic hydrolysis followed by either X-ray crystallographic or chromatographic analysis. The aglycone (1a) of 2 and its C-23 epimer (8a), and the oleanane glycosides (12 and 13) showed cytotoxic activity against HL-60 leukemia cells with IC₅₀ values ranging from 10.6 μM to 101.6 μM. HL-60 cells were much more sensitive to 8a (IC₅₀ 14.8 μM) than 1a (IC₅₀ 101.1 μM), indicating that the C-23 configuration is associated with the cytotoxicity of these cycloartane derivatives. Compound 12 was revealed so as to partially induce apoptotic cell death in HL-60 cells, as was evident from morphology of HL-60 cells treated with 12. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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13 pages, 2555 KiB

Open AccessArticle

Identification of Pinocembrin as an Anti-Glycation Agent and α-Glucosidase Inhibitor from Fingerroot (Boesenbergia rotunda): The Tentative Structure–Activity Relationship towards MG-Trapping Activity

by Thammatee Potipiranun, Sirichai Adisakwattana, Wisuttaya Worawalai, Rico Ramadhan and Preecha Phuwapraisirisan

Molecules 2018, 23(12), 3365; https://doi.org/10.3390/molecules23123365 - 19 Dec 2018

Cited by 26 | Viewed by 5372

Abstract

Diabetes mellitus (DM) is a disease that is caused by a malfunction of carbohydrate metabolism, which plays an important role in the development of long-term diabetic complications. The excess glucose can be transformed to methylglyoxal (MG), a potential precursor of glycation. Glycation is [...] Read more.

Diabetes mellitus (DM) is a disease that is caused by a malfunction of carbohydrate metabolism, which plays an important role in the development of long-term diabetic complications. The excess glucose can be transformed to methylglyoxal (MG), a potential precursor of glycation. Glycation is a spontaneous non-enzymatic reaction that initially yields advanced glycation end-products (AGEs), which ultimately triggers several severe complications. Therefore, the inhibition of AGEs formation is the imperative approach for alleviating diabetic complications. The aim of this research was to investigate the glycation and α-glucosidase inhibitory abilities of compounds isolated from fingerroot. The dichloromethane extract afforded three flavanones, two chalcones, two dihydrochalcones, and one kavalactone. Most of the isolated compounds showed higher inhibition effect against AGEs formation than aminoguanidine (AG). Subsequent evaluation in MG-trapping assay indicated that their trapping potency was relatively comparable to AG. Their structure-activity relationships (SAR) of MG-trapping activity were investigated using the comparison of the structures of flavonoids. In addition, pinocembrin displayed moderate α-glucosidase inhibition against both maltase and sucrose, with IC₅₀ values of 0.35 ± 0.021 and 0.39 ± 0.020 mM, respectively. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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18 pages, 1297 KiB

Open AccessArticle

Phytochemical Profile, Antioxidant and Antidiabetic Activities of Adansonia digitata L. (Baobab) from Mali, as a Source of Health-Promoting Compounds

by Alessandra Braca, Chiara Sinisgalli, Marinella De Leo, Beatrice Muscatello, Pier Luigi Cioni, Luigi Milella, Angela Ostuni, Sergio Giani and Rokia Sanogo

Molecules 2018, 23(12), 3104; https://doi.org/10.3390/molecules23123104 - 27 Nov 2018

Cited by 72 | Viewed by 8345

Abstract

Background: Adansonia digitata L. (Malvaceae), also known as baobab, is a tree attracting recent interest especially due to the high nutritional value of the fruit pulp. However, few studies are reported on the secondary metabolite content, showing high variability depending on the [...] Read more.

Background: Adansonia digitata L. (Malvaceae), also known as baobab, is a tree attracting recent interest especially due to the high nutritional value of the fruit pulp. However, few studies are reported on the secondary metabolite content, showing high variability depending on the geographic region. Methods: In this study, the chemical profiles of Malian commercial baobab fruits and leaves, focused on phenolic content, were investigated by HPLC coupled with a photodiode array (PDA)/UV and an electrospray ionization (ESI) mass spectrometer (MS) and gas chromatography (GC)/MS. In addition, the extracts of fruit pulps obtained from three different markets (Fruits 1, 2, and 3) were evaluated for their total phenolic content (TPC), antioxidant activity and α-glucosidase inhibition. Results: Baobab fruit pulps were found to be rich in procyanidins and flavonol glycosides, with tiliroside as the major constituent. The baobab leaves showed a similar profile respect to the fruits, but with more detected phenolics. All fruit pulp extracts exerted antioxidant activity (highest for Fruit 3) and higher α-glucosidase inhibition than acarbose used as standard. Conclusions: This study confirmed the variability of baobab with different origins and indicated Malian species baobab as a promising source of health-promoting substances. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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6 pages, 971 KiB

Open AccessFeature PaperCommunication

An Example of a Novel Efficient Plant Extraction Technique: Electromagnetic Induction Heating

by Francesco Epifano, Francesca Preziuso, Vito Alessandro Taddeo, Serena Fiorito and Salvatore Genovese

Molecules 2018, 23(11), 3048; https://doi.org/10.3390/molecules23113048 - 21 Nov 2018

Cited by 2 | Viewed by 3078

Abstract

A simple and easy to handle extraction procedure based on the use of electromagnetic induction heating is described. To assess the potential, scopes, and limitations of this novel process, extraction and subsequent HPLC quantification of emodin from an hydroalcoholic extract of rhizome of [...] Read more.

A simple and easy to handle extraction procedure based on the use of electromagnetic induction heating is described. To assess the potential, scopes, and limitations of this novel process, extraction and subsequent HPLC quantification of emodin from an hydroalcoholic extract of rhizome of Rheum palmatum (Chinese rhubarb) was selected as the reference experiment. Maceration at room temperature and by heating, ultrasound-assisted, and microwave-assisted extractions were also carried out for comparison. Results obtained with electromagnetic induction heating showed that this methodology performed largely better both in terms of time process and extraction yields. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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10 pages, 898 KiB

Open AccessArticle

Six New Phragmalin Limonoids from the Stems of Chukrasia tabularis A. Juss

by Yan-Cui Wang, Fan-Dong Kong, Hao Wang, Wen-Li Mei, Shou-Bai Liu, You-Xing Zhao and Hao-Fu Dai

Molecules 2018, 23(11), 3024; https://doi.org/10.3390/molecules23113024 - 20 Nov 2018

Cited by 8 | Viewed by 3224

Abstract

Six new phragmalin limonoids, named moluccensin Z1 (1), moluccensin Z2 (2), carapanolide Y (3), tabulalin N (4), chukvelutilide A1 (5), and velutinasin J (6), as well as two known compounds, chukvelutilide [...] Read more.

Six new phragmalin limonoids, named moluccensin Z1 (1), moluccensin Z2 (2), carapanolide Y (3), tabulalin N (4), chukvelutilide A1 (5), and velutinasin J (6), as well as two known compounds, chukvelutilide A (7) and velutinasin D (8) were isolated from the stems of Chukrasia tabularis A. Juss. The structures of the new compounds 1–6 were confirmed by spectroscopic methods, including IR and HRESIMS, as well as 1D and 2D NMR, and by comparisons with the data of known analogues. All compounds were tested for α-glucosidase and acetylcholinesterase inhibitory activities. However, none of the compounds was active against α-glucosidase and acetylcholinesterase in vitro. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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10 pages, 1325 KiB

Open AccessArticle

Isolation of Chavibetol and Methyleugenol from Essential Oil of Pimenta pseudocaryophyllus by High Performance Liquid Chromatography

by Edenilson dos Santos Niculau, Leandro do Prado Ribeiro, Thiago Felipe Ansante, João Batista Fernandes, Moacir Rossi Forim, Paulo Cezar Vieira, José Djair Vendramim and Maria Fátima das Graças Fernandes Da Silva

Molecules 2018, 23(11), 2909; https://doi.org/10.3390/molecules23112909 - 08 Nov 2018

Cited by 15 | Viewed by 4486

Abstract

A high performance liquid chromatography (HPLC) method was developed for the simultaneous isolation, on a semi-preparative scale, of chavibetol and methyleugenol from the crude essential oil of P. pseudocaryophyllus leaves. The purity of the isolated compounds and their quantifications were developed using GC/FID. [...] Read more.

A high performance liquid chromatography (HPLC) method was developed for the simultaneous isolation, on a semi-preparative scale, of chavibetol and methyleugenol from the crude essential oil of P. pseudocaryophyllus leaves. The purity of the isolated compounds and their quantifications were developed using GC/FID. Chavibetol was isolated with high purity (98.7%) and mass recovery (94.6%). The mass recovery (86.4%) and purity (85.3%) of methyleugenol were lower than those of chavibetol. Both compounds were identified on the basis of spectral analysis. The results suggest that the method can provide chavibetol with high purity, mass recovery, and productivity from crude essential, which will be used in bioassays against stored insect pests. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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12 pages, 982 KiB

Open AccessArticle

Isolation and Identification of Potent Antidiabetic Compounds from Antrodia cinnamomea—An Edible Taiwanese Mushroom

by Hung Tse Huang, San-Lang Wang, Van Bon Nguyen and Yao-Haur Kuo

Molecules 2018, 23(11), 2864; https://doi.org/10.3390/molecules23112864 - 02 Nov 2018

Cited by 31 | Viewed by 4565

Abstract

Antrodia cinnamomea (AC), an edible Taiwanese mushroom, has been recognized as a valuable natural resource with vast biological and medicinal benefits. Recently, the hypoglycemic and anti-diabetic effects of AC were mentioned in several studies. However, no studies have investigated α-glucosidase inhibitors from AC [...] Read more.

Antrodia cinnamomea (AC), an edible Taiwanese mushroom, has been recognized as a valuable natural resource with vast biological and medicinal benefits. Recently, the hypoglycemic and anti-diabetic effects of AC were mentioned in several studies. However, no studies have investigated α-glucosidase inhibitors from AC fruiting bodies (ACFB) as they relate to type 2 diabetes (T2D) treatment. The purpose of this study was to gain evidence of potent α-glucosidase inhibitory effects, as well as isolate, identify and characterize the active compounds of ACFB. The MeOH extract of ACFB demonstrated potent α-glucosidase inhibitory activity, and possessed high pH stability (pH 2–11) and thermostable properties at 40–50 °C. Further purification led to the isolation of eight constituents from ACFB, identified as: 25S-antcin K (1), 25R-antcin K (2), dehydrosulphurenic acid (3), 25S-antcin I (4), 25S-antcin B (5), 25R-antcin B (6), dehydroeburicoic acid (7) and eburicoic acid (8). Notably, the ACFB extract and its identified compounds, except 1, 4, and 6 demonstrated a greater effect (EC₅₀ = 0.025–0.21 mg/mL) than acarbose (EC₅₀ = 0.278 mg/mL). As such, these active compounds were determined to be new potent mushroom α-glucosidase inhibitors. These active compounds were also identified on the HPLC fingerprints of ACFB. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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12 pages, 7544 KiB

Open AccessArticle

Phytotoxic Compounds Isolated from Leaves of the Invasive Weed Xanthium spinosum

by Zhuogeng Yuan, Xiangwei Zheng, Yu Zhao, Ying Liu, Shixing Zhou, Caixia Wei, Yunxia Hu and Hua Shao

Molecules 2018, 23(11), 2840; https://doi.org/10.3390/molecules23112840 - 01 Nov 2018

Cited by 31 | Viewed by 4796

Abstract

The aim of this study was to identify bioactive compounds from leaves of the invasive plant Xanthium spinosum and assess their phytotoxic activity. Activity-guided fractionation led to the isolation of 6 bioactive compounds: xanthatin (1), 1α,5α-epoxyxanthatin (2), 4-epiisoxanthanol ( [...] Read more.

The aim of this study was to identify bioactive compounds from leaves of the invasive plant Xanthium spinosum and assess their phytotoxic activity. Activity-guided fractionation led to the isolation of 6 bioactive compounds: xanthatin (1), 1α,5α-epoxyxanthatin (2), 4-epiisoxanthanol (3), 4-epixanthanol (4), loliolide (5) and dehydrovomifoliol (6). Of them, compounds 2–6 were isolated from the X. spinosum for the first time. The structures of 1–6 were elucidated on the basis of extensive NMR studies and ESI-MS measurements as well as comparison with literature data. All of compounds were evaluated for their phytotoxic activity. Among them, compounds 1–4 exhibited stronger activity on 2 receiver plants compared with the other 2 compounds, with xanthatin (1) being the most potent compound, which suppressed root growth of the dicot plant Amaranthus retroflexus by 32.5%, 39.4%, 84.7% when treated xanthatin (1) at 5, 20, and 100 µg/mL, while for the monocot plant, root growth was inhibited by 14.7%, 28.0%, and 40.0%, respectively. Seedling growth was nearly completely inhibited when the concentration of xanthanolides increased to 500 µg/mL, whereas there was still some seedling growth when loliolide (5) and dehydrovomifoliol (6) were applied at the same concentration. Dehydrovomifoliol (6) did not negatively affect seedling growth of P. annua at all tested concentrations, and root length was still 42.0% of the control when the highest concentration 500 µg/mL was used. This is the first report of the phytotoxicity of 1α,5α-epoxyxanthatin (2), 4-epiisxanthanol (3) and 4-epixanthanol (4). These compounds have the potential to be utilized as natural herbicides, especially 4-epiisoxanthanol (3), which exhibited significant selective activity between the dicot and monocot plants. On the other hand, whether these bioactive substances serve as allelochemicals to facilitate the invasion success of X. spinosum needs to be further studied. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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17 pages, 3710 KiB

Open AccessArticle

Comparative Gene Expression Analysis in WM164 Melanoma Cells Revealed That β-β-Dimethylacrylshikonin Leads to ROS Generation, Loss of Mitochondrial Membrane Potential, and Autophagy Induction

by Nadine Kretschmer, Alexander Deutsch, Christin Durchschein, Beate Rinner, Alexander Stallinger, Juan Carlos Higareda-Almaraz, Marcel Scheideler, Birgit Lohberger and Rudolf Bauer

Molecules 2018, 23(11), 2823; https://doi.org/10.3390/molecules23112823 - 30 Oct 2018

Cited by 20 | Viewed by 4036

Abstract

Skin cancer is currently diagnosed as one in every three cancers. Melanoma, the most aggressive form of skin cancer, is responsible for 79% of skin cancer deaths and the incidence is rising faster than in any other solid tumor type. Previously, we have [...] Read more.

Skin cancer is currently diagnosed as one in every three cancers. Melanoma, the most aggressive form of skin cancer, is responsible for 79% of skin cancer deaths and the incidence is rising faster than in any other solid tumor type. Previously, we have demonstrated that dimethylacrylshikonin (DMAS), isolated from the roots of Onosma paniculata (Boraginaceae), exhibited the lowest IC₅₀ values against different tumor types out of several isolated shikonin derivatives. DMAS was especially cytotoxic towards melanoma cells and led to apoptosis and cell cycle arrest. In this study, we performed a comprehensive gene expression study to investigate the mechanism of action in more detail. Gene expression signature was compared to vehicle-treated WM164 control cells after 24 h of DMAS treatment; where 1192 distinct mRNAs could be identified as expressed in all replicates and 89 were at least 2-fold differentially expressed. DMAS favored catabolic processes and led in particular to p62 increase which is involved in cell growth, survival, and autophagy. More in-depth experiments revealed that DMAS led to autophagy, ROS generation, and loss of mitochondrial membrane potential in different melanoma cells. It has been reported that the induction of an autophagic cell death represents a highly effective approach in melanoma therapy. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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12 pages, 2575 KiB

Open AccessArticle

Isolation of Tricin as a Xanthine Oxidase Inhibitor from Sweet White Clover (Melilotus albus) and Its Distribution in Selected Gramineae Species

by Xiao-Xiao Liu, Shi-Wei Sun, Wen-Jing Yuan, Hua Gao, Yue-Yue Si, Kun Liu, Shuang Zhang, Yang Liu and Wei Wang

Molecules 2018, 23(10), 2719; https://doi.org/10.3390/molecules23102719 - 22 Oct 2018

Cited by 8 | Viewed by 4121

Abstract

Xanthine oxidase, an enzyme present in significant levels in the intestine and liver, metabolizes hypoxanthine to xanthine and xanthine to uric acid in the purine catabolic pathway. An inhibitory compound acting against xanthine oxidase was isolated from sweet white clover (Melilotus albus [...] Read more.

Xanthine oxidase, an enzyme present in significant levels in the intestine and liver, metabolizes hypoxanthine to xanthine and xanthine to uric acid in the purine catabolic pathway. An inhibitory compound acting against xanthine oxidase was isolated from sweet white clover (Melilotus albus) by bioassay and high-performance liquid chromatography guided separation. It was identified as tricin by spectroscopic analysis. Tricin possessed a potent xanthine oxidase inhibitory activity with an IC₅₀ value of 4.13 μM. Further inhibition kinetics data indicated it to be a mixed-type inhibitor and K_i and K_I values were determined to be 0.47 μM and 4.41 μM. To find a rich source of tricin, the distribution of tricin in seven different tissues from four Gramineae species was investigated by high-performance liquid chromatography analysis. The highest amount (1925.05 mg/kg dry materials) was found in the straw of wheat, which is considered as a potentially valuable source of natural tricin. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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16 pages, 1489 KiB

Open AccessFeature PaperArticle

Characterization of Red Wine Proanthocyanidins Using a Putative Proanthocyanidin Database, Amide Hydrophilic Interaction Liquid Chromatography (HILIC), and Time-of-Flight Mass Spectrometry

by Scott Frost, Larry A. Lerno, Jerry Zweigenbaum, Hildegarde Heymann and Susan E. Ebeler

Molecules 2018, 23(10), 2687; https://doi.org/10.3390/molecules23102687 - 18 Oct 2018

Cited by 14 | Viewed by 4161

Abstract

Proanthocyanidins are complex polymers of flavan-3-ol monomers and play a key sensory and health role in foods and beverages. We describe here a novel method for characterizing wine proanthocyanidins using a theoretical database comprised of the chemical formula and exact mass of 996 [...] Read more.

Proanthocyanidins are complex polymers of flavan-3-ol monomers and play a key sensory and health role in foods and beverages. We describe here a novel method for characterizing wine proanthocyanidins using a theoretical database comprised of the chemical formula and exact mass of 996 compounds. The database was constructed using the four primary grape and wine proanthocyanidin monomers: (epi)catechin, (epi)catechin-3-O-gallate, (epi)gallocatechin, and (epi)gallocatechin-3-O-gallate, each combined in all possible combinations up to a polymerization of 10. The database was queried against spectra collected using ultrahigh performance liquid chromatography (UHLPC) with a hydrophilic interaction liquid chromatography (HILIC) column and coupled to a high-resolution accurate mass quadrupole time-of-flight mass spectrometer (Q-TOF MS). Two wine samples produced with different post fermentation maceration were analyzed using the presented method to demonstrate application for analysis of diverse proanthocyanidins. The first sample was pressed immediately at the end of fermentation when all sugar had been utilized and the second received eight weeks of post fermentation maceration. The HILIC column combined with high resolution tandem mass spectrometry and database matching provided tentative identification of 89 compounds with excellent resolution and without the need for two-dimensional separations. The identified compounds were visualized with Kendrick mass analysis, a simple technique allowing for rapid visualization of which compounds are present in a given sample. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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17 pages, 1135 KiB

Open AccessArticle

Antioxidant Activity and Phytochemical Characterization of Senecio clivicolus Wedd.

by Immacolata Faraone, Dilip K. Rai, Lucia Chiummiento, Eloy Fernandez, Alka Choudhary, Flavio Prinzo and Luigi Milella

Molecules 2018, 23(10), 2497; https://doi.org/10.3390/molecules23102497 - 29 Sep 2018

Cited by 32 | Viewed by 4572

Abstract

Antioxidant phytochemicals play a key role in oxidative stress control and in the prevention of related disorders, such as premature aging, degenerative diseases, diabetes, and cancer. The aim of this study was to investigate the potential antioxidant activity and the phytochemical profile of [...] Read more.

Antioxidant phytochemicals play a key role in oxidative stress control and in the prevention of related disorders, such as premature aging, degenerative diseases, diabetes, and cancer. The aim of this study was to investigate the potential antioxidant activity and the phytochemical profile of Senecio clivicolus Wedd., a perennial shrub, belonging to the Asteraceae family. Despite the wide interest of this family, this specie has not been investigated yet. S. clivicolus aerial parts were extracted with 96% ethanol. Then, the ethanol extract was fractionated by liquid/liquid extraction using an increasing solvents polarity. Total polyphenol and terpenoid contents were measured. Moreover, the antioxidant activity was evaluated by six different complementary in vitro assays. The Relative Antioxidant Capacity Index (RACI) was used to compare data obtained by different tests. The sample showing the highest RACI was subjected to characterization and quantitation of its phenolic composition using LC-MS/MS analysis. The ethyl acetate fraction, investigated by LC-MS/MS analysis, showed 30 compounds, most of them are chlorogenic acid and flavonoid derivatives. To the best of our knowledge, this is the first report about the evaluation of antioxidant activity and phytochemical profile of S. clivicolus, underlying the importance of this species as a source of health-promoting phytochemicals. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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12 pages, 1306 KiB

Open AccessArticle

Azukisapogenol Triterpene Glycosides from Oxytropis chiliophylla Royle

by Jun Wang, Hongshuai Yang, Yang Liu, Kelsang Norbo, Kewu Zeng, Mingbo Zhao, Hong Liang, Pengfei Tu and Qingying Zhang

Molecules 2018, 23(10), 2448; https://doi.org/10.3390/molecules23102448 - 25 Sep 2018

Cited by 1 | Viewed by 2929

Abstract

Eight azukisapogenol triterpene glycosides, including five new compounds, oxychiliotriterpenosides A–E (1–5), two new methyl glucuronide derivatives that proved to be artifacts, oxychiliotriterpenoside E-glucuronic acid methyl ester (6) and myrioside B-glucuronic acid methyl ester (7), and [...] Read more.

Eight azukisapogenol triterpene glycosides, including five new compounds, oxychiliotriterpenosides A–E (1–5), two new methyl glucuronide derivatives that proved to be artifacts, oxychiliotriterpenoside E-glucuronic acid methyl ester (6) and myrioside B-glucuronic acid methyl ester (7), and a known one, myrioside B (8), was isolated from the aerial part of Oxytropis chiliophylla Royle. Their structures were elucidated based on extensive spectroscopic analyses and chemical methods. Triterpene glycosides were first obtained from O. chiliophylla, and those containing a galactose unit (1, 2, 5 and 6) and diglucosidic or triglucosidic linkage at C-29 (1–4), were reported from Oxytropis species for the first time, which might be recognized as a chemotaxonomic feature of O. chiliophylla. All isolated compounds were evaluated for their anti-inflammatory activities against NO production using lipopolysaccharide (LPS)-induced RAW 264.7 cells, but no compounds showed potent inhibition on NO production. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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13 pages, 2473 KiB

Open AccessArticle

Isolation, Characterization and Antitumor Effect on DU145 Cells of a Main Polysaccharide in Pollen of Chinese Wolfberry

by Fei Chen, Linwu Ran, Jia Mi, Yamei Yan, Lu Lu, Bo Jin, Xiaoying Li and Youlong Cao

Molecules 2018, 23(10), 2430; https://doi.org/10.3390/molecules23102430 - 21 Sep 2018

Cited by 26 | Viewed by 4001

Abstract

Modern studies have shown that pollen has a certain role in the treatment of prostate-related diseases. In the present study, pollen polysaccharides from Chinese wolfberry (WPPs) were extracted by hot-water extraction and ethanol precipitation, further purified by chromatography on a DEAE-cellulose column and [...] Read more.

Modern studies have shown that pollen has a certain role in the treatment of prostate-related diseases. In the present study, pollen polysaccharides from Chinese wolfberry (WPPs) were extracted by hot-water extraction and ethanol precipitation, further purified by chromatography on a DEAE-cellulose column and Sephadex G-100 column. Homogeneous polysaccharide CF1 of WPPS was obtained, the molecular weight of which was estimated to be 1540.10 ± 48.78 kDa by HPGPC-ELSD. HPLC with PMP derivatization analysis indicated that the monosaccharide compositions of CF1 were mannose, glucuronic acid, galacturonic acid, xylose, galactose, arabinose, and trehalose, in a molar ratio of 0.68:0.59:0.27:0.24:0.22:0.67:0.08. The antitumor effects of CF1 upon MTT, Tunel assay and flow cytometry assay were investigated in vitro. The results showed that CF1 exhibited a dose-dependent antiproliferative effect, with an IC50 value of 374.11 μg/mL against DU145 prostate cancer cells. Tunel assay and flow cytometry assay showed that the antitumor activity of CF1 was related to apoptosis in vitro. The present study suggested that the CF1 of WPPs might be a potential source of antitumor functional food or agent. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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20 pages, 4053 KiB

Open AccessArticle

Influence of Eugenia uniflora Extract on Adhesion to Human Buccal Epithelial Cells, Biofilm Formation, and Cell Surface Hydrophobicity of Candida spp. from the Oral Cavity of Kidney Transplant Recipients

by Luanda B. F. C. Souza, Walicyranison P. Silva-Rocha, Magda R. A. Ferreira, Luiz Alberto L. Soares, Terezinha I. E. Svidzinski, Eveline P. Milan, Regina H. Pires, Ana Marisa Fusco Almeida, Maria José S. Mendes-Giannini and Guilherme Maranhão Chaves

Molecules 2018, 23(10), 2418; https://doi.org/10.3390/molecules23102418 - 20 Sep 2018

Cited by 26 | Viewed by 4677

Abstract

This study evaluated the influence of the extract of Eugenia uniflora in adhesion to human buccal epithelial cells (HBEC) biofilm formation and cell surface hydrophobicity (CSH) of Candida spp. isolated from the oral cavity of kidney transplant patients. To evaluate virulence attributes in [...] Read more.

This study evaluated the influence of the extract of Eugenia uniflora in adhesion to human buccal epithelial cells (HBEC) biofilm formation and cell surface hydrophobicity (CSH) of Candida spp. isolated from the oral cavity of kidney transplant patients. To evaluate virulence attributes in vitro, nine yeasts were grown in the presence and absence of 1000 μg/mL of the extract. Adhesion was quantified using the number of Candida cells adhered to 150 HBEC determined by optical microscope. Biofilm formation was evaluated using two methodologies: XTT (2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) and crystal violet assay, and further analyzed by electronic scan microscopy. CSH was quantified with the microbial adhesion to hydrocarbons test. We could detect that the extract of E. uniflora was able to reduce adhesion to HBEC and CSH for both Candida albicans and non-Candida albicans Candida species. We also observed a statistically significant reduced ability to form biofilms in biofilm-producing strains using both methods of quantification. However, two highly biofilm-producing strains of Candida tropicalis had a very large reduction in biofilm formation. This study reinforces the idea that besides growth inhibition, E. uniflora may interfere with the expression of some virulence factors of Candida spp. and may be possibly applied in the future as a novel antifungal agent. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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21 pages, 2885 KiB

Open AccessArticle

Characterization of α-Glucosidase Inhibitors from Clinacanthus nutans Lindau Leaves by Gas Chromatography-Mass Spectrometry-Based Metabolomics and Molecular Docking Simulation

by Suganya Murugesu, Zalikha Ibrahim, Qamar-Uddin Ahmed, Nik-Idris Nik Yusoff, Bisha-Fathamah Uzir, Vikneswari Perumal, Faridah Abas, Khozirah Saari, Hesham El-Seedi and Alfi Khatib

Molecules 2018, 23(9), 2402; https://doi.org/10.3390/molecules23092402 - 19 Sep 2018

Cited by 55 | Viewed by 7790

Abstract

Background: Clinacanthus nutans (C. nutans) is an Acanthaceae herbal shrub traditionally consumed to treat various diseases including diabetes in Malaysia. This study was designed to evaluate the α-glucosidase inhibitory activity of C. nutans leaves extracts, and to identify the metabolites responsible [...] Read more.

Background: Clinacanthus nutans (C. nutans) is an Acanthaceae herbal shrub traditionally consumed to treat various diseases including diabetes in Malaysia. This study was designed to evaluate the α-glucosidase inhibitory activity of C. nutans leaves extracts, and to identify the metabolites responsible for the bioactivity. Methods: Crude extract obtained from the dried leaves using 80% methanolic solution was further partitioned using different polarity solvents. The resultant extracts were investigated for their α-glucosidase inhibitory potential followed by metabolites profiling using the gas chromatography tandem with mass spectrometry (GC-MS). Results: Multivariate data analysis was developed by correlating the bioactivity, and GC-MS data generated a suitable partial least square (PLS) model resulting in 11 bioactive compounds, namely, palmitic acid, phytol, hexadecanoic acid (methyl ester), 1-monopalmitin, stigmast-5-ene, pentadecanoic acid, heptadecanoic acid, 1-linolenoylglycerol, glycerol monostearate, alpha-tocospiro B, and stigmasterol. In-silico study via molecular docking was carried out using the crystal structure Saccharomyces cerevisiae isomaltase (PDB code: 3A4A). Interactions between the inhibitors and the protein were predicted involving residues, namely LYS156, THR310, PRO312, LEU313, GLU411, and ASN415 with hydrogen bond, while PHE314 and ARG315 with hydrophobic bonding. Conclusion: The study provides informative data on the potential α-glucosidase inhibitors identified in C. nutans leaves, indicating the plant’s therapeutic effect to manage hyperglycemia. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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15 pages, 2276 KiB

Open AccessArticle

Expression of Bioactive Lunasin Peptide in Transgenic Rice Grains for the Application in Functional Food

by Guixing Ren, Yuqiong Hao, Yingying Zhu, Zhenxing Shi and Gang Zhao

Molecules 2018, 23(9), 2373; https://doi.org/10.3390/molecules23092373 - 17 Sep 2018

Cited by 11 | Viewed by 6013

Abstract

Lunasin, a bioactive peptide initially isolated from soybean, has anticancer, anti-inflammatory, and antioxidant activity. Due its great application value, lunasin seems to be a candidate gene in improving the nutritional value of crops. In this study, lunasin was inserted into the rice genome [...] Read more.

Lunasin, a bioactive peptide initially isolated from soybean, has anticancer, anti-inflammatory, and antioxidant activity. Due its great application value, lunasin seems to be a candidate gene in improving the nutritional value of crops. In this study, lunasin was inserted into the rice genome to evaluate whether it was feasible to express lunasin using the rice expression system and improve the bioactivity of protein in rice for our needs. We generatedlunasin-overexpressing rice lines, and chose three independent transgenic rice lines for further study. The lunasin content in trans-lunasin rice detected by UPLC-MS/MS was 1.01 × 10⁻³ g·kg⁻¹ dry rice flour with grease removal in the lunasin extracts. The antioxidant efficacy of LET (lunasin-enriched fraction from trans-lunasin rice) and PEW (peptide-enriched fraction from wild type rice) was compared. Due to the presence of lunasin, LET showed higher (p < 0.05) antioxidant activity than PEW. LET exhibited high DPPH radical scavenging activity (IC₅₀ value, 8 g·L⁻¹), strong ABTS⁺ radical scavenging activity (IC₅₀ value, 1.18 g·L⁻¹), and great oxygen radical scavenging activity (170 μmol·L⁻¹ Trolox equivalents when the concentration reached 4 g·L⁻¹). Moreover, LET presented significantly higher (p < 0.05) anti-inflammatory activity on macrophage cells, and the NO production and the release of pro-inflammatory cytokines (IL-6, MCP1, and TNF-α) were significantly inhibited by LET. However, because of the low purity, LET showed weaker antioxidant and anti-inflammatory activity when compared to the Lunasin standard. These results suggested that it is feasible to use the rice expression system to express the exogenous lunasin in rice, and lunasin-overexpressing rice seems to be a candidate resource for application in functional food. Rice rich in lunasin is beneficial for human health, and could be used as a functional food in the diets of cancer and obese patients in the future. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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15 pages, 3360 KiB

Open AccessArticle

Antioxidant Activity and Neuroprotective Activity of Stilbenoids in Rat Primary Cortex Neurons via the PI3K/Akt Signalling Pathway

by Haichao Wen, Zheng Fu, Yangji Wei, Xiaoxu Zhang, Liyan Ma, Liwei Gu and Jingming Li

Molecules 2018, 23(9), 2328; https://doi.org/10.3390/molecules23092328 - 12 Sep 2018

Cited by 23 | Viewed by 4184

Abstract

Antioxidant activity and neuroprotective activity of three stilbenoids, namely, trans-4-hydroxystilbene (THS), trans-3,5,4′-trihydroxy-stilbene (resveratrol, RES), and trans-3′,4′,3,5-tetrahydroxy-stilbene (piceatannol, PIC), against β-amyloid (Aβ)-induced neurotoxicity in rat primary cortex neurons were evaluated. THS, RES, and PIC significantly scavenged DPPH• and •OH radicals. All [...] Read more.

Antioxidant activity and neuroprotective activity of three stilbenoids, namely, trans-4-hydroxystilbene (THS), trans-3,5,4′-trihydroxy-stilbene (resveratrol, RES), and trans-3′,4′,3,5-tetrahydroxy-stilbene (piceatannol, PIC), against β-amyloid (Aβ)-induced neurotoxicity in rat primary cortex neurons were evaluated. THS, RES, and PIC significantly scavenged DPPH• and •OH radicals. All three stilbenoids were able to inhibit Aβ neurotoxicity by decreasing intracellular reactive oxygen species (ROS) via the PI3K/Akt signalling pathway. Specifically, stilbenoids significantly promoted Akt phosphorylation; suppressed Bcl-2/Bax expression; and inhibited caspase-9, caspase-3, and PARP cleavage. Molecular docking between stilbenoids with Akt indicated that stilbenoids could form hydrogen bond interactions with the COOH-terminal region of Akt. Additionally, the neuroprotective activity of stilbenoids correlated with the number and position of hydroxyl groups. The lack of meta-dihydroxyl groups on THS did not affect its neuroprotective activity in comparison with RES, whereas the ortho-dihydroxyl moiety on PIC significantly enhanced neuroprotective activity. These results provide new insights into the correlation between the biological activity and chemical structure of stilbenoids. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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15 pages, 1803 KiB

Open AccessArticle

Depsidone Derivatives and a Cyclopeptide Produced by Marine Fungus Aspergillus unguis under Chemical Induction and by Its Plasma Induced Mutant

by Wen-Cong Yang, Hai-Yan Bao, Ya-Yue Liu, Ying-Ying Nie, Jing-Ming Yang, Peng-Zhi Hong and Yi Zhang

Molecules 2018, 23(9), 2245; https://doi.org/10.3390/molecules23092245 - 03 Sep 2018

Cited by 28 | Viewed by 4582

Abstract

A new depsidone derivative (1), aspergillusidone G, was isolated from a marine fungus Aspergillus unguis, together with eight known depsidones (2‒9) and a cyclic peptide (10): agonodepside A (2), nornidulin (3 [...] Read more.

A new depsidone derivative (1), aspergillusidone G, was isolated from a marine fungus Aspergillus unguis, together with eight known depsidones (2‒9) and a cyclic peptide (10): agonodepside A (2), nornidulin (3), nidulin (4), aspergillusidone F (5), unguinol (6), aspergillusidone C (7), 2-chlorounguinol (8), aspergillusidone A (9), and unguisin A (10). Compounds 1‒4 and 7‒9 were obtained from the plasma induced mutant of this fungus, while 5, 6, and 10 were isolated from the original strain under chemical induction. Their structures were identified using spectroscopic analysis, as well as by comparison with literature data. The HPLC fingerprint analysis indicates that chemical induction and plasma mutagenesis effectively influenced the secondary metabolism, which may be due to their regulation in the key steps in depsidone biosynthesis. In bioassays, compound 9 inhibited acetylcholinesterase (AChE) with IC₅₀ in 56.75 μM. Compounds 1, 5, 7, 8, and 9 showed moderate to strong activity towards different microbes. Compounds 3, 4, and 5 exhibited potent larvicidality against brine shrimp. In docking studies, higher negative CDOCKER interaction energy and richer strong interactions between AChE and 9 explained the greater activity of 9 compared to 1. Chemical induction and plasma mutagenesis can be used as tools to expand the chemodiversity of fungi and obtain useful natural products. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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14 pages, 2075 KiB

Open AccessArticle

A Comparative Metabolomics Analysis Reveals the Tissue-Specific Phenolic Profiling in Two Acanthopanax Species

by Ke-Xin Wu, Jia Liu, Yang Liu, Xiao-Rui Guo, Li-Qiang Mu, Xiao-Hang Hu and Zhong-Hua Tang

Molecules 2018, 23(8), 2078; https://doi.org/10.3390/molecules23082078 - 20 Aug 2018

Cited by 23 | Viewed by 4029

Abstract

Acanthopanax senticosus (Rupr. Maxim.) Harms (ASH) and Acanthopanax sessiliflorus (Rupr. Maxim.) Seem (ASS), are members of the Araliaceae family, and both are used in Asian countries. These herbals have drawn much attention in recent years due to their strong biological activity, with innocuity [...] Read more.

Acanthopanax senticosus (Rupr. Maxim.) Harms (ASH) and Acanthopanax sessiliflorus (Rupr. Maxim.) Seem (ASS), are members of the Araliaceae family, and both are used in Asian countries. These herbals have drawn much attention in recent years due to their strong biological activity, with innocuity and little side effects. However, the common and distinct mode of compound profiles between ASH and ASS is still unclear. In this study, a high performance liquid chromatograph-mass spectrometry (HPLC-MS) method was developed to simultaneously quantify the seven major active compounds, including protocatechuate, eleutheroside B, eleutheroside E, isofraxidin, hyperoside, kaempferol and oleanolic acid. Then the targeted metabolomics were conducted to identify 19 phenolic compounds, with tight relation to the above mentioned active compounds, including nine C6C3C6-type, six C6C3-type and four C6C1-type in the two Acanthopanax species studied here. The results showed that the seven active compounds presented a similar trend of changes in different tissues, with more abundant accumulation in roots and stems for both plants. From the view of plant species, the ASH plants possess higher abundance of compounds, especially in the tissues of roots and stems. For phenolics, the 19 phenols detected here could be clearly grouped into five main clusters based on their tissue-specific accumulation patterns. Roots are the tissue for the most abundance of their accumulations. C6C3C6-type compounds are the most widely existing type in both plants. In conclusion, the tissue- and species-specificity in accumulation of seven active compounds and phenolics were revealed in two Acanthopanax species. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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14 pages, 1772 KiB

Open AccessArticle

Effect of Volatile Organic Chemicals in Chrysanthemum indicum Linné on Blood Pressure and Electroencephalogram

by Da-Som Kim, Young-Min Goo, Jinju Cho, Jookyeong Lee, Dong Yeol Lee, Seung Mi Sin, Young Sook Kil, Won Min Jeong, Keon Hee Ko, Ki Jeung Yang, Yun Geun Kim, Sang Gon Kim, Kiseong Kim, Young Jun Kim, Jae Kyeom Kim and Eui-Cheol Shin

Molecules 2018, 23(8), 2063; https://doi.org/10.3390/molecules23082063 - 17 Aug 2018

Cited by 28 | Viewed by 6504

Abstract

This study identified the volatile organic compounds in the essential oils that are extracted from Chrysanthemum indicum Linné (C. indicum Linné) and investigated the effects of the inhalation of these compounds. We detected a total of 41 volatile organic compounds, including 32 [...] Read more.

This study identified the volatile organic compounds in the essential oils that are extracted from Chrysanthemum indicum Linné (C. indicum Linné) and investigated the effects of the inhalation of these compounds. We detected a total of 41 volatile organic compounds, including 32 hydrocarbons, four acids, three alcohols, two ketones, and one aldehyde. In a sniffing test, seven types of volatile organic compounds were identified. Furthermore, the volatile organic compounds in C. indicum Linné that were identified were found to be derived from 1,8-cineole and camphor. After inhalation of the essential oils, the subjects’ systolic blood pressure and heart rate decreased. This indicates that inhalation of the essential oils extracted from C. indicum Linné provides mental and physical relaxation. We examined the changes in electroencephalogram findings that are observed after C. indicum Linné essential oil inhalation. An increase in theta and alpha waves, which usually appear during relaxation, as well as a decrease in beta and gamma waves, which appear during brain activity such as excessive attention, were noted. These results indicate that C. indicum Linné essential oil inhalation helps to reduce blood pressure and may provide mental and physical relaxation. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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7 pages, 795 KiB

Open AccessArticle

Isolation and Purification of Galloyl, Caffeoyl, and Hexahydroxydiphenoyl Esters of Glucoses from Balanophora simaoensis by High-Speed Countercurrent Chromatography and Their Antioxidant Activities In Vitro

by Lei Fang, Tian-Tian He, Xiao Wang and Jie Zhou

Molecules 2018, 23(8), 2027; https://doi.org/10.3390/molecules23082027 - 14 Aug 2018

Cited by 10 | Viewed by 3291

Abstract

High-speed counter-current chromatography was used to separate and purify galloyl, caffeoyl, and hexahydroxydiphenoyl esters of glucoses from the aerial parts of the parasitic plant Balanophora simaoensis for the first time using n-hexane-ethyl acetate-methanol-water (1:2:1:2, v/v) as the optimum solvent [...] Read more.

High-speed counter-current chromatography was used to separate and purify galloyl, caffeoyl, and hexahydroxydiphenoyl esters of glucoses from the aerial parts of the parasitic plant Balanophora simaoensis for the first time using n-hexane-ethyl acetate-methanol-water (1:2:1:2, v/v) as the optimum solvent system. Accordingly, 1-O-(E)-caffeoyl-3-O-galloyl-β-d-glucopyranose (I, 12.5 mg), 1-O-(E)-caffeoyl-3-O-galloyl-4,6-(S)-hexahydroxydiphenoyl-β-d-glucopyranose (II, 27.2 mg), and 1-O-(E)-caffeoyl-4,6-(S)-hexahydroxydiphenoyl-β-d-glucopyranose (III, 52.8 mg) with 98.0%, 98.5%, and 98.7% purities, respectively, were purified from 210 mg crude extract of B. simaoensis in a one-step separation. The structures of the glucose esters were identified by electrospray ionization mass spectrometry (ESI-MS) and nuclear magnetic resonance spectra (NMR). Their antioxidant activities were evaluated by measuring their inhibition activity on liver microsomal lipid peroxidation induced by the Fe²⁺-Cys system in vitro. Compounds I–III showed significant antioxidant activities with IC₅₀ values ranging from 2.51 to 6.68 μm, respectively. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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10 pages, 3679 KiB

Open AccessCommunication

DPP-IV Inhibitory Potentials of Flavonol Glycosides Isolated from the Seeds of Lens culinaris: In Vitro and Molecular Docking Analyses

by Bo-Ram Kim, Hyo Young Kim, Inhee Choi, Jin-Baek Kim, Chang Hyun Jin and Ah-Reum Han

Molecules 2018, 23(8), 1998; https://doi.org/10.3390/molecules23081998 - 10 Aug 2018

Cited by 70 | Viewed by 5058

Abstract

Dipeptidyl peptidase IV (DPP-IV), a new target for the treatment of type 2 diabetes mellitus, degrades incretins such as glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide. DPP-IV inhibitors shorten the inactivation of GLP-1, permitting the incretin to stimulate insulin release, thereby combating [...] Read more.

Dipeptidyl peptidase IV (DPP-IV), a new target for the treatment of type 2 diabetes mellitus, degrades incretins such as glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide. DPP-IV inhibitors shorten the inactivation of GLP-1, permitting the incretin to stimulate insulin release, thereby combating hyperglycemia. In our ongoing search for new DPP-IV inhibitors from medicinal plants and foods, three flavonol glycosides (1–3) were isolated from the seeds of Lens culinaris Medikus (Fabaceae) and tested for their DPP-IV–inhibitory activity. We demonstrated for the first time, that compounds 1–3 inhibited DPP-IV activity in a concentration-dependent manner in our in vitro bioassay system. In addition, molecular docking experiments of compounds 1–3 within the binding pocket of DPP-IV were conducted. All investigated compounds readily fit within the active sites of DPP-IV, in low-energy conformations characterized by the flavone core structure having optimal electrostatic attractive interactions with the catalytic triad residues of DPP-IV. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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17 pages, 2718 KiB

Open AccessArticle

Toxin-Pathogen Synergy Reshaping Detoxification and Antioxidant Defense Mechanism of Oligonychus afrasiaticus (McGregor)

by Ahmed Mohammed AlJabr, Abid Hussain and Muhammad Rizwan-ul-haq

Molecules 2018, 23(8), 1978; https://doi.org/10.3390/molecules23081978 - 08 Aug 2018

Cited by 12 | Viewed by 3448

Abstract

Current study reveals the likelihood to use pathogen and toxin mutually as an effective and eco-friendly strategy for Oligonychus afrasiaticus (McGregor) management, which could reduce toxicant dose and host killing time. Therefore, phytol and Beauveria bassiana in different proportions were evaluated to determine [...] Read more.

Current study reveals the likelihood to use pathogen and toxin mutually as an effective and eco-friendly strategy for Oligonychus afrasiaticus (McGregor) management, which could reduce toxicant dose and host killing time. Therefore, phytol and Beauveria bassiana in different proportions were evaluated to determine their effectiveness. Prior to ascertaining host mortality and defense mechanisms, we have recorded in vitro action of phytol using different concentrations (0.70, 1.40, 2.10, 2.80, and 3.50 mg/mL) against B. bassiana suspension. In vitro compatibility assays revealed that growth parameters (vegetative growth, sporulation, and viability) of B. bassiana were least affected by the action of phytol at all tested concentrations. Biological Index of B. bassiana exhibited compatibility with phytol allowed us to conduct Joint toxicity bioassays in which phytol and spores mixed in different proportions in order to attain maximum treatment effect in terms of high mortality at low concentration under short time. Results revealed that joint-application exhibited both synergistic (treatments with higher proportions of phytol), and antagonistic interaction (treatments with higher proportions of spores) interactions. Biochemical mechanisms involved in host antioxidant and detoxification response were explored by quantifying their respective enzymatic activities. Lethality of different treatments induced different patterns of detoxification enzymes including glutathione S-transferase (GST) and acetylcholinesterase (AchE). Overall, the least potent treatments (20% phytol:80% spores, and 40% phytol:60% spores) established in the current study induced relatively higher GST and AchE activities. On the other hand, the most potent treatment (80% phytol:20% spores) at its maximum concentration exhibited negligible relative GST and AchE activities. Antioxidant enzyme activities of CAT and SOD measured in the current study showed moderate to complex interaction might because of toxin-pathogen remarkable synergy. This study suggested that joint application of phytol with B. bassiana spores have shown tremendous acaricidal potential and found to be promising new strategy for controlling old world date mites. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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22 pages, 1787 KiB

Open AccessReview

Allamanda cathartica: A Review of the Phytochemistry, Pharmacology, Toxicology, and Biotechnology

by Vera L. Petricevich and Rodolfo Abarca-Vargas

Molecules 2019, 24(7), 1238; https://doi.org/10.3390/molecules24071238 - 29 Mar 2019

Cited by 17 | Viewed by 10910

Abstract

In this work, we explore the current knowledge about the phytochemistry and in vitro and in vivo evaluations of the extracts and, where appropriate, the main active components characterized and isolated from the Allamanda cathartica. Of the 15 Allamanda species, most phytochemical, [...] Read more.

In this work, we explore the current knowledge about the phytochemistry and in vitro and in vivo evaluations of the extracts and, where appropriate, the main active components characterized and isolated from the Allamanda cathartica. Of the 15 Allamanda species, most phytochemical, pharmacological, and toxicological studies have focused on A. cathartica. These plants are used for the treatment of various health disorders. Numerous phytochemical investigations of plants from the A. cathartica have shown the presence of hydrocarbons, alcohols, esters, ethers, aldehydes, ketones, fatty acids, phospholipids, volatile compounds, phenolic compounds, flavonoids, alkaloids, steroids, terpenes, lactones, and carbohydrates. Various studies have confirmed that extracts and active substances isolated from the A. cathartica have multiple pharmacological activities. The species A. cathartica has emerged as a source of traditional medicine used for human health. Further studies on the phytochemical, pharmacological, and toxicological properties and their mechanisms of action, safety, and efficacy in the species of A. cathartica is recommended. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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33 pages, 15038 KiB

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Linear Triquinane Sesquiterpenoids: Their Isolation, Structures, Biological Activities, and Chemical Synthesis

by Yi Qiu, Wen-Jian Lan, Hou-Jin Li and Liu-Ping Chen

Molecules 2018, 23(9), 2095; https://doi.org/10.3390/molecules23092095 - 21 Aug 2018

Cited by 40 | Viewed by 6434

Abstract

Linear triquinane sesquiterpenoids represent an important class of natural products. Most of these compounds were isolated from fungi, sponges, and soft corals, and many of them displayed a wide range of biological activities. On account of their structural diversity and complexity, linear triquinane [...] Read more.

Linear triquinane sesquiterpenoids represent an important class of natural products. Most of these compounds were isolated from fungi, sponges, and soft corals, and many of them displayed a wide range of biological activities. On account of their structural diversity and complexity, linear triquinane sesquiterpenoids present new challenges for chemical structure identification and total synthesis. 118 linear triquinane sesquiterpenoids were classified into 8 types, named types I–VIII, based on the carbon skeleton and the position of carbon substituents. Their isolation, structure elucidations, biological activities, and chemical synthesis were reviewed. This paper cited 102 articles from 1947 to 2018. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

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