Molecules

15 pages, 1617 KiB

Open AccessArticle

Synthesis and Tuberculostatic Activity Evaluation of Novel Benzazoles with Alkyl, Cycloalkyl or Pyridine Moiety

by Malwina Krause, Henryk Foks, Ewa Augustynowicz-Kopeć, Agnieszka Napiórkowska, Małgorzata Szczesio and Katarzyna Gobis

Molecules 2018, 23(4), 985; https://doi.org/10.3390/molecules23040985 - 23 Apr 2018

Cited by 16 | Viewed by 5584

Abstract

Compounds possessing benzimidazole system exhibit significant antituberculous activity. In order to examine how structure modifications affect tuberculostatic activity, a series of benzazole derivatives were synthesized and screened for their antitubercular activity. The compounds 1–20 were obtained by the reaction between o [...] Read more.

Compounds possessing benzimidazole system exhibit significant antituberculous activity. In order to examine how structure modifications affect tuberculostatic activity, a series of benzazole derivatives were synthesized and screened for their antitubercular activity. The compounds 1–20 were obtained by the reaction between o-diamine, o-aminophenol, or o-aminothiophenol with carboxylic acids or thioamides. The newly synthesized compounds were characterized by IR, ¹H-NMR, ¹³C-NMR spectra, and elemental analysis. Synthesized benzazoles were evaluated for their tuberculostatic activity toward Mycobacterium tuberculosis strains. Quantum chemical calculations were performed to study the molecular geometry and the electronic structure of benzimidazoles GK-151B, 4, 6, and benzoxazole 11, using the Gaussian 03W software (Gaussian, Inc., Wallingford, CT, USA). Three-dimensional structure of benzimidazoles 1–3, MC-9, and GK-151B was determined by ab initio calculation using Gamess-US software. The activity of the received benzimidazoles was moderate or good. All of the benzoxazoles and benzothiazoles demonstrated much lower activity. Benzoxazoles were less active by about 50 times, and benzothiazole by 100 times than the benzimidazole analogs. Quantum chemical calculations showed differences in the distribution of electrostatic potential in the benzazole system of benzimidazoles and benzoxazoles. Three-dimensional structure calculations revealed how the parity of the alkyl substituent at the C2 position impacts the activity. Benzimidazole system is essential for the antituberculosis activity that is associated with the presence of the imine nitrogen atom in N-1 position. Its replacement by an oxygen or sulfur atom results in a decrease of the activity. The parity of the alkyl substituent at the C-2 position also modifies the activity. Full article

(This article belongs to the Collection Antibiotics & Superbugs: New Strategies to Combat Antimicrobial Resistance)

► Show Figures

Figure 1

16 pages, 1386 KiB

Open AccessArticle

Quantitative Analysis of Four Catechins from Green Tea Extract in Human Plasma Using Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry for Pharmacokinetic Studies

by Jeong-Eun Park, Tae-Eun Kim and Kwang-Hee Shin

Molecules 2018, 23(4), 984; https://doi.org/10.3390/molecules23040984 - 23 Apr 2018

Cited by 12 | Viewed by 6311

Abstract

Green tea is consumed as a beverage worldwide and has beneficial effects, such as a lower risk of cardiovascular disease and cancer. A quantitative analysis of the beneficial components in plasma is important for understanding the potential health benefits of green tea. Four [...] Read more.

Green tea is consumed as a beverage worldwide and has beneficial effects, such as a lower risk of cardiovascular disease and cancer. A quantitative analysis of the beneficial components in plasma is important for understanding the potential health benefits of green tea. Four catechins—epigallocatechin-3-gallate (EGCG), epicatechin-3-gallate (ECG), epigallocatechin (EGC), and epicatechin (EC)—which account for the majority of the components of green tea, were analyzed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). In this study, a validated method was optimized to obtain the blood concentrations after the one-time ingestion of 630 mg green tea extract with digoxin and then after the ingestion of 630 mg green tea repeatedly for 15 days. The calibration curve, including the LLOQ, was constructed over 1–500 ng/mL for EGCG, ECG, and EGC and 0.1–50 ng/mL for EC. The method for inter- and intra-validation was applied, acceptable for both accuracy and precision. We successfully developed an appropriate UPLC-MS/MS method for human plasma with good reproducibility and sensitivity. Thus, this method could be applied for future preclinical and clinical studies on EGCG, ECG, EGC, and EC. Full article

(This article belongs to the Collection Advances in Liquid Separation Techniques for Food and Pharmaceutical Analysis)

► Show Figures

Graphical abstract

12 pages, 4445 KiB

Open AccessArticle

Plasma and Salivary Non-Urate Total Antioxidant Capacity Does Not Depend on Dietary Vitamin C, E, or β-Carotene Intake in Older Subjects

by Anna Gawron-Skarbek, Agnieszka Guligowska, Anna Prymont-Przymińska, Dariusz Nowak and Tomasz Kostka

Molecules 2018, 23(4), 983; https://doi.org/10.3390/molecules23040983 - 23 Apr 2018

Cited by 7 | Viewed by 4086

Abstract

The native Total Antioxidant Capacity (TAC) of plasma and saliva is generally determined by uric acid (UA). Several studies have assessed the impact of habitual dietary antioxidative vitamin intake on TAC, but it remains unknown whether it influences Non-Urate Total Antioxidant Capacity (Nu-TAC), [...] Read more.

The native Total Antioxidant Capacity (TAC) of plasma and saliva is generally determined by uric acid (UA). Several studies have assessed the impact of habitual dietary antioxidative vitamin intake on TAC, but it remains unknown whether it influences Non-Urate Total Antioxidant Capacity (Nu-TAC), i.e., TAC after enzymatic UA elimination. The purpose of this study was to assess whether the intake of antioxidative vitamins C, E, and β-carotene, provided with usual daily food rations, affects plasma and salivary Nu-TAC. The study involved 56 older subjects (aged 66.9 ± 4.3 years), divided into two age- and sex-matched groups: group 1 (n = 28), with lower combined vitamin C, E, and β-carotene intake, and group 2 (n = 28), with higher intake. A 24 h dietary recall was obtained from each individual. Nu-TAC was assessed simultaneously with two methods in plasma (Ferric Reducing Ability of Plasma—Nu-FRAP, 2.2-diphenyl-1-picryl-hydrazyl—Nu-DPPH) and in saliva (Nu-FRAS and Nu-DPPHS test). No differences were found in the Nu-TAC parameters between the groups, either in plasma (Nu-FRAP, Nu-DPPH) or in saliva (Nu-FRAS, Nu-DPPHS) (p > 0.05). No plasma or salivary Nu-TAC indices correlated with dietary vitamin C, E, or β-carotene intake or with other nutrients. Habitual, not extra-supplemented dietary intake does not significantly affect plasma or salivary Nu-TAC. Full article

(This article belongs to the Special Issue Dietary Antioxidants: Evidence of Protective Effects against Chronic Disease)

► Show Figures

Figure 1

14 pages, 3475 KiB

Open AccessArticle

Development of Triamcinolone Acetonide-Loaded Nanostructured Lipid Carriers (NLCs) for Buccal Drug Delivery Using the Box-Behnken Design

by Pakorn Kraisit and Narong Sarisuta

Molecules 2018, 23(4), 982; https://doi.org/10.3390/molecules23040982 - 23 Apr 2018

Cited by 37 | Viewed by 5731

Abstract

The aim of this present work was to prepare triamcinolone acetonide (TA)-loaded nanostructured lipid carriers (TA-loaded NLCs) for buccal drug delivery systems using the Box-Behnken design. A hot homogenization method was used to prepare the TA-loaded NLCs. Spermaceti (X₁), soybean oil [...] Read more.

The aim of this present work was to prepare triamcinolone acetonide (TA)-loaded nanostructured lipid carriers (TA-loaded NLCs) for buccal drug delivery systems using the Box-Behnken design. A hot homogenization method was used to prepare the TA-loaded NLCs. Spermaceti (X₁), soybean oil (X₂), and Tween 80 (X₃) were used as solid lipid, liquid lipid, and stabilizer, respectively. The particle size of TA-loaded NLCs was lower than 200 nm and the zeta potential displayed the negative charge in all formulations. The percentage encapsulation efficiency (%EE) of the TA-loaded NLCs showed that it was higher than 80% for all formulations. Field emission scanning electron microscope (FESEM) confirmed that the size of TA-loaded NLCs was approximately 100 nm and energy-dispersive X-ray spectroscopy (EDS) confirmed that the TA could be incorporated in the NLC system. The Higuchi model gave the highest value of the R², indicating that this model was a fit for the TA release profiles of TA-loaded NLCs. Confocal laser scanning microscopy (CLSM) was used to observe the drug penetration within the porcine buccal mucosa and Nile red-loaded NLCs showed significantly higher penetration depth at 8 h than at 2 h. Therefore, TA-loaded NLCs could be an efficient carrier for drug delivery through the buccal mucosa. Full article

► Show Figures

Graphical abstract

10 pages, 1494 KiB

Open AccessArticle

Synthesis of a 1,2-Dithienylethene-Containing Donor-Acceptor Polymer via Palladium-Catalyzed Direct Arylation Polymerization (DArP)

by Masayuki Wakioka, Natsumi Yamashita, Hiroki Mori, Yasushi Nishihara and Fumiyuki Ozawa

Molecules 2018, 23(4), 981; https://doi.org/10.3390/molecules23040981 - 23 Apr 2018

Cited by 16 | Viewed by 5621

Abstract

This paper reports the synthesis of D-A polymers containing 1,2-dithienylethene (DTE) units via palladium-catalyzed direct arylation polymerization (DArP). The reaction of dibromoisoindigo (1-Br) and DTE (2-H), in the presence of Pd₂(dba)₃·CHCl [...] Read more.

This paper reports the synthesis of D-A polymers containing 1,2-dithienylethene (DTE) units via palladium-catalyzed direct arylation polymerization (DArP). The reaction of dibromoisoindigo (1-Br) and DTE (2-H), in the presence of Pd₂(dba)₃·CHCl₃ (0.5 mol%), P(2-MeOC₆H₄)₃ (L1) (2 mol%), pivalic acid (1 equiv) as catalyst precursors, and Cs₂CO₃ (3 equiv) as a base affords poly(1-alt-2) with a high molecular weight (M_n up to 44,900). Although, it has been known that monomers, with plural C–H bonds, tend to form insoluble materials via direct arylation at undesirable C–H positions; the reaction of 1-Br and 2-H cleanly proceeds without insolubilization. The resulting polymer has a well-controlled structure and exhibits good charge transfer characteristics in an organic field-effect transistor (OFET), compared to the polymer produced by Migita–Kosugi–Stille cross-coupling polymerization. The DArP product displays an ideal linear relationship in the current–voltage curve, whereas the Migita–Kosugi–Stille product shows a V_G-dependent change in the charge mobility. Full article

(This article belongs to the Special Issue Direct (Hetero)Arylation: A New Tool for Organic Electronics)

► Show Figures

Graphical abstract

2 pages, 145 KiB

Open AccessEditorial

Biomedical Applications of Polylactide (PLA) and Its Copolymers

by Gaetano Giammona and Emanuela Fabiola Craparo

Molecules 2018, 23(4), 980; https://doi.org/10.3390/molecules23040980 - 23 Apr 2018

Cited by 20 | Viewed by 3877

Abstract

n/a Full article

(This article belongs to the Special Issue Biomedical Applications of Polylactide (PLA) and its Copolymers)

11 pages, 1316 KiB

Open AccessFeature PaperCommunication

In(III)-TMSBr-Catalyzed Cascade Reaction of Diarylalkynes with Acrylates for the Synthesis of Aryldihydronaphthalene Derivatives

by Qiu-Chi Zhang, Wen-Wei Zhang, Liang Shen, Zhi-Liang Shen and Teck-Peng Loh

Molecules 2018, 23(4), 979; https://doi.org/10.3390/molecules23040979 - 23 Apr 2018

Cited by 3 | Viewed by 5093

Abstract

A combined Lewis acid system comprising of two or more Lewis acids occasionally exhibits augmented catalytic activity in organic transformations which are otherwise unrealizable by either of the components exclusively. On the other hand, the efficient construction of multiple new C-C bonds and [...] Read more.

A combined Lewis acid system comprising of two or more Lewis acids occasionally exhibits augmented catalytic activity in organic transformations which are otherwise unrealizable by either of the components exclusively. On the other hand, the efficient construction of multiple new C-C bonds and polycyclic structures in minimal steps remains a subject of great interest in both academia and industry. Herein we report an efficient method to assemble aryldihydronaphthalene derivatives via a cascade reaction of diarylalkynes with acrylates under the catalysis of a combined Lewis acid derived from In(III) salt and TMSBr. Full article

(This article belongs to the Special Issue Indium in Organic Synthesis)

► Show Figures

Graphical abstract

11 pages, 942 KiB

Open AccessArticle

Anti-Helicobacter, Antitubercular and Cytotoxic Activities of Scalaranes from the Red Sea Sponge Hyrtios erectus

by Abdulrahman M. Alahdal, Hani Z. Asfour, Safwat A. Ahmed, Ahmad O. Noor, Ahmed M. Al-Abd, Mahmoud A. Elfaky and Sameh S. Elhady

Molecules 2018, 23(4), 978; https://doi.org/10.3390/molecules23040978 - 23 Apr 2018

Cited by 33 | Viewed by 5447

Abstract

The Red Sea specimen of the marine sponge Hyrtios erectus (order Dictyoceratida) was found to contain scalarane-type sesterterpenes. 12-O-deacetyl-12,19-di-epi-scalarin (14), a new scalarane sesterterpenoid, along with fourteen previously-reported scalarane-type sesterterpenes (1–13 and 15) [...] Read more.

The Red Sea specimen of the marine sponge Hyrtios erectus (order Dictyoceratida) was found to contain scalarane-type sesterterpenes. 12-O-deacetyl-12,19-di-epi-scalarin (14), a new scalarane sesterterpenoid, along with fourteen previously-reported scalarane-type sesterterpenes (1–13 and 15) have been isolated. The chemical structures of the isolated compounds were elucidated on the basis of detailed 1D and 2D NMR spectral data and mass spectroscopy, as well as by comparison with reported data. The anti-Helicobacter pylori, antitubercular and cytotoxic activities of all fifteen compounds were evaluated to reveal the potency of Compounds 1, 2, 3, 4, 6, 7 and 10. Amongst these, Compounds 1, 3, 4, 6 and 10 displayed a promising bioactivity profile, possessing potent activities in the antitubercular and anti-H. pylori bioassay. Compounds 2 and 7 showed the most promising cytotoxic profile, while Compounds 1 and 10 showed a moderate cytotoxic profile against MCF-7, HCT-116 and HepG2 cell lines. Full article

(This article belongs to the Section Natural Products Chemistry)

► Show Figures

Graphical abstract

13 pages, 7609 KiB

Open AccessArticle

Novel Inhibitor Discovery of Staphylococcus aureus Sortase B and the Mechanism Confirmation via Molecular Modeling

by Guizhen Wang, Xiyan Wang, Lin Sun, Yawen Gao, Xiaodi Niu and Hongsu Wang

Molecules 2018, 23(4), 977; https://doi.org/10.3390/molecules23040977 - 23 Apr 2018

Cited by 7 | Viewed by 4001

Abstract

SortaseB (SrtB) plays a critical role in Staphylococcus aureus (S. aureus) infections. According to the reports in the literature, SrtB can anchor the IsdC to the cell wall to capture iron from the host to achieve a successful invasion. On the [...] Read more.

SortaseB (SrtB) plays a critical role in Staphylococcus aureus (S. aureus) infections. According to the reports in the literature, SrtB can anchor the IsdC to the cell wall to capture iron from the host to achieve a successful invasion. On the other hand, SrtB could also affect the adhesion of S. aureus to host cells based on previous studies. Here, we report about a novel SrtB inhibitor, coptisine, a natural compound that does not exhibit antibacterial activity but can inhibit the SrtB activity in vitro. A cytotoxicity test indicated that coptisine protects human lung epithelial cells from S. aureus. In addition, coptisine can reduce the adhesion of S. aureus to human lung epithelial cells based on the result of plate colony counting assay. Molecular dynamics simulation revealed that coptisine can bind to the active pocket of SrtB, leading to its activity loss. Through the calculation of binding free energy between ligand and protein, site-directed mutagenesis and fluorescence spectroscopy quenching methods, it was confirmed that residues of Arg115, Asn116, and Ile182 played a vital role in the interaction of SrtB with coptisine. These data provide the theoretical basis for the therapy option to the infections caused by S. aureus. Full article

► Show Figures

Figure 1

8 pages, 1526 KiB

Open AccessArticle

Convenient Synthesis of Thiohydantoins, Imidazole-2-thiones and Imidazo[2,1-b]thiazol-4-iums from Polymer-Supported α-Acylamino Ketones

by Petra Králová, Michal Maloň, Hiroyuki Koshino and Miroslav Soural

Molecules 2018, 23(4), 976; https://doi.org/10.3390/molecules23040976 - 23 Apr 2018

Cited by 5 | Viewed by 4416

Abstract

The preparation of 5-methylene-thiohydantoins using solid-phase synthesis is reported in this paper. After sulfonylation of immobilized Ser (t-Bu)-OH with 4-nitrobenzenesulfonyl chloride followed by alkylation with various bromoketones, the 4-Nos group was removed and the resulting polymer-supported α-acylamino ketones reacted with Fmoc-isothiocyanate. [...] Read more.

The preparation of 5-methylene-thiohydantoins using solid-phase synthesis is reported in this paper. After sulfonylation of immobilized Ser (t-Bu)-OH with 4-nitrobenzenesulfonyl chloride followed by alkylation with various bromoketones, the 4-Nos group was removed and the resulting polymer-supported α-acylamino ketones reacted with Fmoc-isothiocyanate. Cleavage of the Fmoc protecting group was followed by the spontaneous cyclative cleavage releasing the 5-methylene-thiohydantoin derivatives from the polymer support. Reduction with triethylsilane (TES) yielded the corresponding 5-methyl-thiohydantoins. When Fmoc-isothiocyanate was replaced with alkyl isothiocyanates, the trifluoroacetic acid (TFA) mediated cleavage from the polymer support, which was followed by the cyclization reaction and the imidazo[2,1-b]thiazol-4-iums were obtained. Their conversion in deuterated dimethylsulfoxide led to imidazole-2-thiones. Full article

(This article belongs to the Special Issue Solid Phase Synthesis)

► Show Figures

Graphical abstract

12 pages, 3221 KiB

Open AccessArticle

Study on the Bactericidal Mechanism of Atmospheric-Pressure Low-Temperature Plasma against Escherichia coli and Its Application in Fresh-Cut Cucumbers

by Yan Sun, Zhiwei Zhang and Shiqing Wang

Molecules 2018, 23(4), 975; https://doi.org/10.3390/molecules23040975 - 22 Apr 2018

Cited by 28 | Viewed by 5843

Abstract

Atmospheric-pressure low-temperature plasma (APLTP) was used to study the bactericidal mechanism against Escherichia coli (E. coli) and its application in the sterilization of fresh-cut cucumbers. The morphological changes of E. coli cells subjected to APLTP were observed by scanning electron microscopy [...] Read more.

Atmospheric-pressure low-temperature plasma (APLTP) was used to study the bactericidal mechanism against Escherichia coli (E. coli) and its application in the sterilization of fresh-cut cucumbers. The morphological changes of E. coli cells subjected to APLTP were observed by scanning electron microscopy (SEM). Cell death was evaluated by fluorescence microscopy (FM). Cell membrane permeability was measured by conductivity changes, and the amount of soluble protein leakage in the bacterial supernatant was determined by measurement of protein concentration. Additionally, the effects of APLTP on the physicochemical and sensory quality of fresh-cut cucumber were studied by assessing the changes of moisture content, soluble solid content (SSC), pH value, color, relative conductivity, malondialdehyde (MDA) level, vitamin C (Vc) content, aroma composition and microstructure. The results showed that the E. coli cell morphology was changed due to the charged particles and active components produced by APLTP. The E. coli cell wall and cell membrane ruptured, cell content leaked out, cells lost the ability to reproduce and self-replicate, and the function of cell metabolism was directly affected and led to E. coli inactivation. In addition, there was no significant effect on physicochemical properties and sensory quality of fresh-cut cucumbers. Full article

► Show Figures

Graphical abstract

11 pages, 1498 KiB

Open AccessArticle

Application of the Response Surface Methodology to Optimize the Fermentation Parameters for Enhanced Docosahexaenoic Acid (DHA) Production by Thraustochytrium sp. ATCC 26185

by Kang Wu, Lijian Ding, Peng Zhu, Shuang Li and Shan He

Molecules 2018, 23(4), 974; https://doi.org/10.3390/molecules23040974 - 22 Apr 2018

Cited by 20 | Viewed by 4330

Abstract

The aim of this study was to determine the cumulative effect of fermentation parameters and enhance the production of docosahexaenoic acid (DHA) by Thraustochytrium sp. ATCC 26185 using response surface methodology (RSM). Among the eight variables screened for effects of fermentation parameters on [...] Read more.

The aim of this study was to determine the cumulative effect of fermentation parameters and enhance the production of docosahexaenoic acid (DHA) by Thraustochytrium sp. ATCC 26185 using response surface methodology (RSM). Among the eight variables screened for effects of fermentation parameters on DHA production by Plackett-Burman design (PBD), the initial pH, inoculum volume, and fermentation volume were found to be most significant. The Box-Behnken design was applied to derive a statistical model for optimizing these three fermentation parameters for DHA production. The optimal parameters for maximum DHA production were initial pH: 6.89, inoculum volume: 4.16%, and fermentation volume: 140.47 mL, respectively. The maximum yield of DHA production was 1.68 g/L, which was in agreement with predicted values. An increase in DHA production was achieved by optimizing the initial pH, fermentation, and inoculum volume parameters. This optimization strategy led to a significant increase in the amount of DHA produced, from 1.16 g/L to 1.68 g/L. Thraustochytrium sp. ATCC 26185 is a promising resource for microbial DHA production due to the high-level yield of DHA that it produces, and the capacity for large-scale fermentation of this organism. Full article

(This article belongs to the Section Natural Products Chemistry)

► Show Figures

Figure 1

14 pages, 7585 KiB

Open AccessArticle

Antioxidant and Cytoprotective Effects of Kukoamines A and B: Comparison and Positional Isomeric Effect

by Xican Li, Jian Lin, Ban Chen, Hong Xie and Dongfeng Chen

Molecules 2018, 23(4), 973; https://doi.org/10.3390/molecules23040973 - 21 Apr 2018

Cited by 25 | Viewed by 4970

Abstract

In this study, two natural phenolic polyamines, kukoamine A and B, were comparatively investigated for their antioxidant and cytoprotective effects in Fenton-damaged bone marrow-derived mesenchymal stem cells (bmMSCs). When compared with kukoamine B, kukoamine A consistently demonstrated higher IC₅₀ values in PTIO•-scavenging [...] Read more.

In this study, two natural phenolic polyamines, kukoamine A and B, were comparatively investigated for their antioxidant and cytoprotective effects in Fenton-damaged bone marrow-derived mesenchymal stem cells (bmMSCs). When compared with kukoamine B, kukoamine A consistently demonstrated higher IC₅₀ values in PTIO•-scavenging (pH 7.4), Cu²⁺-reducing, DPPH•-scavenging, •O₂⁻-scavenging, and •OH-scavenging assays. However, in the PTIO•-scavenging assay, the IC₅₀ values of each kukoamine varied with pH value. In the Fe²⁺-chelating assay, kukoamine B presented greater UV-Vis absorption and darker color than kukoamine A. In the HPLC–ESI–MS/MS analysis, kukoamine A with DPPH• produced radical-adduct-formation (RAF) peaks (m/z 922 and 713). The 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl (MTT) assay suggested that both kukoamines concentration-dependently increased the viabilities of Fenton-damaged bmMSCs at 56.5–188.4 μM. However, kukoamine A showed lower viability percentages than kukoamine B. In conclusion, the two isomers kukoamine A and B can protect bmMSCs from Fenton-induced damage, possibly through direct or indirect antioxidant pathways, including electron-transfer, proton-transfer, hydrogen atom transfer, RAF, and Fe²⁺-chelating. Since kukoamine B possesses higher potentials than kukoamine A in these pathways, kukoamine B is thus superior to kukoamine A in terms of cytoprotection. These differences can ultimately be attributed to positional isomeric effects. Full article

(This article belongs to the Special Issue The Antioxidant Capacities of Natural Products)

► Show Figures

Graphical abstract

14 pages, 14761 KiB

Open AccessArticle

The Effects of Chinese Herbal Medicines on the Quorum Sensing-Regulated Virulence in Pseudomonas aeruginosa PAO1

by Yee Meng Chong, Kah Yan How, Wai Fong Yin and Kok Gan Chan

Molecules 2018, 23(4), 972; https://doi.org/10.3390/molecules23040972 - 21 Apr 2018

Cited by 16 | Viewed by 5146

Abstract

The quorum sensing (QS) system has been used by many opportunistic pathogenic bacteria to coordinate their virulence determinants in relation to cell-population density. As antibiotic-resistant bacteria are on the rise, interference with QS has been regarded as a novel way to control bacterial [...] Read more.

The quorum sensing (QS) system has been used by many opportunistic pathogenic bacteria to coordinate their virulence determinants in relation to cell-population density. As antibiotic-resistant bacteria are on the rise, interference with QS has been regarded as a novel way to control bacterial infections. As such, many plant-based natural products have been widely explored for their therapeutic roles. These natural products may contain anti-QS compounds that could block QS signals generation or transmission to combat QS pathogens. In this study, we report the anti-QS activities of four different Chinese herbal plant extracts: Poria cum Radix pini, Angelica dahurica, Rhizoma cibotii and Schizonepeta tenuifolia, on Pseudomonas aeruginosa PAO1. All the plants extracted using hexane, chloroform and methanol were tested and found to impair swarming motility and pyocyanin production in P. aeruginosa PAO1, particularly by Poria cum Radix pini. In addition, all the plant extracts also inhibited violacein production in C. violaceum CV026 up to 50% while bioluminescence activities were reduced in lux-based E. coli biosensors, pSB401 and pSB1075, up to about 57%. These anti-QS properties of the four medicinal plants are the first documentation that demonstrates a potential approach to attenuate pathogens’ virulence determinants. Full article

(This article belongs to the Section Medicinal Chemistry)

► Show Figures

Figure 1

10 pages, 1828 KiB

Open AccessArticle

Evaluation of Manganese Chloride’s Effect on Biosynthetic Properties of In Vitro Cultures of Eschscholzia californica Cham.

by Andrea Balažová, Júlia Urdová, František Bilka, Ivana Holková, Branislav Horváth, Vladimír Forman and Pavel Mučaji

Molecules 2018, 23(4), 971; https://doi.org/10.3390/molecules23040971 - 21 Apr 2018

Cited by 4 | Viewed by 4109

Abstract

The basal production of secondary metabolites in medicinal plants is limited. One of the effective approaches that encourages plants to produce a remarkable amount of precious compounds is an application of elicitors. Our work was focused on the elicitation of Eschscholzia californica Cham. [...] Read more.

The basal production of secondary metabolites in medicinal plants is limited. One of the effective approaches that encourages plants to produce a remarkable amount of precious compounds is an application of elicitors. Our work was focused on the elicitation of Eschscholzia californica Cham. suspension cultures using various concentrations of MnCl₂ (5; 10; 15 mg/L) with the aim of evaluating its effect on sanguinarine, chelerythrine, and macarpine production and gene expression of enzymes involved in the biosynthesis of mentioned secondary metabolites (BBE, 4′-OMT, CYP80B1) or in defense processes (LOX). Suspension cultures were exposed to elicitor for 24, 48, and 72 h. The content of alkaloids in phytomass was determined on the basis of their fluorescence properties. The relative mRNA expression of selected genes was analyzed using the ΔΔCt value method. PCR products were evaluated by melting curve analysis to confirm the specific amplification. Our results demonstrated that Eschscholzia californica Cham. cell suspension cultures evince sensitivity to the presence of MnCl₂ in growth media resulting in the increased production of benzophenanthridine alkaloids and gene expression of selected enzymes. Manganese chloride seems to be a potential elicitor supporting natural biosynthetic properties in plant cell cultures and can be applied for the sustained production of valuable secondary metabolites. Full article

(This article belongs to the Section Natural Products Chemistry)

► Show Figures

Figure 1

11 pages, 3450 KiB

Open AccessArticle

Microbial Oxidation of the Fusidic Acid Side Chain by Cunninghamella echinulata

by Abdel-Rahim S. Ibrahim, Khaled M. Elokely, Daneel Ferreira and Amany E. Ragab

Molecules 2018, 23(4), 970; https://doi.org/10.3390/molecules23040970 - 21 Apr 2018

Cited by 6 | Viewed by 4963

Abstract

Biotransformation of fusidic acid (1) was accomplished using a battery of microorganisms including Cunninghamella echinulata NRRL 1382, which converted fusidic acid (1) into three new metabolites 2–4 and the known metabolite 5. These metabolites were identified [...] Read more.

Biotransformation of fusidic acid (1) was accomplished using a battery of microorganisms including Cunninghamella echinulata NRRL 1382, which converted fusidic acid (1) into three new metabolites 2–4 and the known metabolite 5. These metabolites were identified using 1D and 2D NMR and HRESI-FTMS data. Structural assignment of the compounds was supported via computation of ¹H- and ¹³C-NMR chemical shifts. Compounds 2 and 3 were assigned as the 27-hydroxy and 26-hydroxy derivatives of fusidic acid, respectively. Subsequent oxidation of 3 afforded aldehyde 4 and the dicarboxylic acid 5. Compounds 2, 4 and 5 were screened for antimicrobial activity against different Gram positive and negative bacteria, Mycobacterium smegmatis, M. intercellulare and Candida albicans. The compounds showed lower activity compared to fusidic acid against the tested strains. Molecular docking studies were carried out to assist the structural assignments and predict the binding modes of the metabolites. Full article

(This article belongs to the Special Issue Isolation and Structure Elucidation of Bioactive Compounds (Dedicated to the memory of the late Professor Charles D. Hufford))

► Show Figures

Graphical abstract

15 pages, 3287 KiB

Open AccessArticle

Self-Assembly Behavior of Amphiphilic Janus Dendrimers in Water: A Combined Experimental and Coarse-Grained Molecular Dynamics Simulation Approach

by Mariana E. Elizondo-García, Valeria Márquez-Miranda, Ingrid Araya-Durán, Jesús A. Valencia-Gallegos and Fernando D. González-Nilo

Molecules 2018, 23(4), 969; https://doi.org/10.3390/molecules23040969 - 21 Apr 2018

Cited by 8 | Viewed by 6529

Abstract

Amphiphilic Janus dendrimers (JDs) are repetitively branched molecules with hydrophilic and hydrophobic components that self-assemble in water to form a variety of morphologies, including vesicles analogous to liposomes with potential pharmaceutical and medical application. To date, the self-assembly of JDs has not been [...] Read more.

Amphiphilic Janus dendrimers (JDs) are repetitively branched molecules with hydrophilic and hydrophobic components that self-assemble in water to form a variety of morphologies, including vesicles analogous to liposomes with potential pharmaceutical and medical application. To date, the self-assembly of JDs has not been fully investigated thus it is important to gain insight into its mechanism and dependence on JDs’ molecular structure. In this study, the aggregation behavior in water of a second-generation bis-MPA JD was evaluated using experimental and computational methods. Dispersions of JDs in water were carried out using the thin-film hydration and ethanol injection methods. Resulting assemblies were characterized by dynamic light scattering, confocal microscopy, and atomic force microscopy. Furthermore, a coarse-grained molecular dynamics (CG-MD) simulation was performed to study the mechanism of JDs aggregation. The obtaining of assemblies in water with no interdigitated bilayers was confirmed by the experimental characterization and CG-MD simulation. Assemblies with dendrimersome characteristics were obtained using the ethanol injection method. The results of this study establish a relationship between the molecular structure of the JD and the properties of its aggregates in water. Thus, our findings could be relevant for the design of novel JDs with tailored assemblies suitable for drug delivery systems. Full article

(This article belongs to the Special Issue Dendrimers in Medicine)

► Show Figures

Graphical abstract

13 pages, 12352 KiB

Open AccessArticle

Investigation on Species Authenticity for Herbal Products of Celastrus Orbiculatus and Tripterygum Wilfordii from Markets Using ITS2 Barcoding

by Jingjing Zhang, Xin Hu, Ping Wang, Bisheng Huang, Wei Sun, Chao Xiong, Zhigang Hu and Shilin Chen

Molecules 2018, 23(4), 967; https://doi.org/10.3390/molecules23040967 - 21 Apr 2018

Cited by 13 | Viewed by 4744

Abstract

Herbal material is both a medicine and a commodity. Accurate identification of herbal materials is necessary to ensure the safety and effectiveness of medication. With this work, we initiated an identification method to investigate the species authenticity for herbal products of Celastrus orbiculatus [...] Read more.

Herbal material is both a medicine and a commodity. Accurate identification of herbal materials is necessary to ensure the safety and effectiveness of medication. With this work, we initiated an identification method to investigate the species authenticity for herbal products of Celastrus orbiculatus and Tripterygum wilfordii utilizing DNA barcoding technology. An ITS2 (internal transcribed spacer two) barcode database including 59 sequences was successfully established to estimate the reliability of species-level identification for Celastrus and Tripterygium. Our findings showed that ITS2 can effectively and clearly distinguish C. orbiculatus, T. wilfordii and its congeners. Then, we investigated the proportions and varieties of adulterant species in the herbal markets. The data from ITS2 region indicated that 13 (62%) of the 21 samples labeled as “Nan-she-teng” and eight (31%) of the 26 samples labeled as “Lei-gong-teng” were authentic; the remaining were adulterants. Of the 47 herbal products, approximately 55% of the product identity were not in accordance with the label. In summary, we support the efficacy of the ITS2 barcode for the traceability of C. orbiculatus and T. wilfordii, and the present study provides one method and reference for the identification of the herbal materials and adulterants in the medicinal markets. Full article

► Show Figures

Graphical abstract

15 pages, 39278 KiB

Open AccessArticle

Co-Localization of Crotamine with Internal Membranes and Accentuated Accumulation in Tumor Cells

by Nicole Caroline Mambelli-Lisboa, Juliana Mozer Sciani, Alvaro Rossan Brandão Prieto da Silva and Irina Kerkis

Molecules 2018, 23(4), 968; https://doi.org/10.3390/molecules23040968 - 20 Apr 2018

Cited by 15 | Viewed by 5758

Abstract

Crotamine is a highly cationic; cysteine rich, cross-linked, low molecular mass cell penetrating peptide (CPP) from the venom of the South American rattlesnake. Potential application of crotamine in biomedicine may require its large-scale purification. To overcome difficulties related with the purification of natural [...] Read more.

Crotamine is a highly cationic; cysteine rich, cross-linked, low molecular mass cell penetrating peptide (CPP) from the venom of the South American rattlesnake. Potential application of crotamine in biomedicine may require its large-scale purification. To overcome difficulties related with the purification of natural crotamine (nCrot) we aimed in the present study to synthesize and characterize a crotamine analog (sCrot) as well investigate its CPP activity. Mass spectrometry analysis demonstrates that sCrot and nCrot have equal molecular mass and biological function—the capacity to induce spastic paralysis in the hind limbs in mice. sCrot CPP activity was evaluated in a wide range of tumor and non-tumor cell tests performed at different time points. We demonstrate that sCrot-Cy3 showed distinct co-localization patterns with intracellular membranes inside the tumor and non-tumor cells. Time-lapse microscopy and quantification of sCrot-Cy3 fluorescence signalss in living tumor versus non-tumor cells revealed a significant statistical difference in the fluorescence intensity observed in tumor cells. These data suggest a possible use of sCrot as a molecular probe for tumor cells, as well as, for the selective delivery of anticancer molecules into these tumors. Full article

(This article belongs to the Special Issue Natural Toxins/Molecules (and Derivatives) from Animal Venoms: From Basic Research to Therapeutic Applications)

► Show Figures

Graphical abstract

15 pages, 8741 KiB

Open AccessFeature PaperReview

Dentromers, a Family of Super Dendrimers with Specific Properties and Applications

by Didier Astruc, Christophe Deraedt, Rodrigue Djeda, Catia Ornelas, Xiang Liu, Amalia Rapakousiou, Jaime Ruiz, Yanlan Wang and Qi Wang

Molecules 2018, 23(4), 966; https://doi.org/10.3390/molecules23040966 - 20 Apr 2018

Cited by 20 | Viewed by 5927

Abstract

Dentromers (from dentro, δεντρο: tree in Greek), and meros (μεροσ, in greek: part) are introduced as a family of dendrimers constructed according to successive divergent 1 → 3 branching. The smaller dentromers have 27 terminal branches. With alcohol termini they were originally [...] Read more.

Dentromers (from dentro, δεντρο: tree in Greek), and meros (μεροσ, in greek: part) are introduced as a family of dendrimers constructed according to successive divergent 1 → 3 branching. The smaller dentromers have 27 terminal branches. With alcohol termini they were originally named arborols by Newkome, who pioneered 1 → 3 constructions of dendrimers and dendrons. Giant dentromers have been constructed and decorated in particular with ferrocene and other redox active groups. The synthesis, specific properties, and applications are examined in this mini review article dedicated to Don Tomalia, with an emphasis on dense peripheral packing favoring the functions of encapsulation, redox sensing, and micellar template for catalysis in water and aqueous solvents. Full article

(This article belongs to the Special Issue Dendrimers: A Themed Issue in Honor of Professor Donald A. Tomalia on the Occasion of His 80th Birthday)

► Show Figures

Figure 1

11 pages, 4568 KiB

Open AccessReview

The Role of Catechins in Cellular Responses to Oxidative Stress

by Jurga Bernatoniene and Dalia Marija Kopustinskiene

Molecules 2018, 23(4), 965; https://doi.org/10.3390/molecules23040965 - 20 Apr 2018

Cited by 361 | Viewed by 20577

Abstract

Catechins are polyphenolic compounds—flavanols of the flavonoid family found in a variety of plants. Green tea, wine and cocoa-based products are the main dietary sources of these flavanols. Catechins have potent antioxidant properties, although in some cases they may act in the cell [...] Read more.

Catechins are polyphenolic compounds—flavanols of the flavonoid family found in a variety of plants. Green tea, wine and cocoa-based products are the main dietary sources of these flavanols. Catechins have potent antioxidant properties, although in some cases they may act in the cell as pro-oxidants. Catechins are reactive oxygen species (ROS) scavengers and metal ion chelators, whereas their indirect antioxidant activities comprise induction of antioxidant enzymes, inhibition of pro-oxidant enzymes, and production of the phase II detoxification enzymes and antioxidant enzymes. Oxidative stress and ROS are implicated in aging and related dysfunctions, such as neurodegenerative disease, cancer, cardiovascular diseases, and diabetes. Due to their antioxidant properties, catechins may be beneficial in preventing and protecting against diseases caused by oxidative stress. This article reviews the biochemical properties of catechins, their antioxidant activity, and the mechanisms of action involved in the prevention of oxidative stress-caused diseases. Full article

(This article belongs to the Special Issue Catechin in Human Health and Disease)

► Show Figures

Figure 1

18 pages, 1783 KiB

Open AccessArticle

Magnetic Properties of Metal–Organic Coordination Networks Based on 3d Transition Metal Atoms

by María Blanco-Rey, Ane Sarasola, Corneliu Nistor, Luca Persichetti, Christian Stamm, Cinthia Piamonteze, Pietro Gambardella, Sebastian Stepanow, Mikhail M. Otrokov, Vitaly N. Golovach and Andres Arnau

Molecules 2018, 23(4), 964; https://doi.org/10.3390/molecules23040964 - 20 Apr 2018

Cited by 9 | Viewed by 6400

Abstract

The magnetic anisotropy and exchange coupling between spins localized at the positions of 3d transition metal atoms forming two-dimensional metal–organic coordination networks (MOCNs) grown on a Au(111) metal surface are studied. In particular, we consider MOCNs made of Ni or Mn metal centers [...] Read more.

The magnetic anisotropy and exchange coupling between spins localized at the positions of 3d transition metal atoms forming two-dimensional metal–organic coordination networks (MOCNs) grown on a Au(111) metal surface are studied. In particular, we consider MOCNs made of Ni or Mn metal centers linked by 7,7,8,8-tetracyanoquinodimethane (TCNQ) organic ligands, which form rectangular networks with 1:1 stoichiometry. Based on the analysis of X-ray magnetic circular dichroism (XMCD) data taken at T = 2.5 K, we find that Ni atoms in the Ni–TCNQ MOCNs are coupled ferromagnetically and do not show any significant magnetic anisotropy, while Mn atoms in the Mn–TCNQ MOCNs are coupled antiferromagnetically and do show a weak magnetic anisotropy with in-plane magnetization. We explain these observations using both a model Hamiltonian based on mean-field Weiss theory and density functional theory calculations that include spin–orbit coupling. Our main conclusion is that the antiferromagnetic coupling between Mn spins and the in-plane magnetization of the Mn spins can be explained by neglecting effects due to the presence of the Au(111) surface, while for Ni–TCNQ the metal surface plays a role in determining the absence of magnetic anisotropy in the system. Full article

(This article belongs to the Special Issue Electronic Structure Calculations Applied to Magnetic Phenomena)

► Show Figures

Figure 1

34 pages, 1517 KiB

Open AccessReview

Modified Fusarium Mycotoxins in Cereals and Their Products—Metabolism, Occurrence, and Toxicity: An Updated Review

by Marcin Bryła, Agnieszka Waśkiewicz, Edyta Ksieniewicz-Woźniak, Krystyna Szymczyk and Renata Jędrzejczak

Molecules 2018, 23(4), 963; https://doi.org/10.3390/molecules23040963 - 20 Apr 2018

Cited by 88 | Viewed by 8227

Abstract

Mycotoxins are secondary fungal metabolites, toxic to humans, animals and plants. Under the influence of various factors, mycotoxins may undergo modifications of their chemical structure. One of the methods of mycotoxin modification is a transformation occurring in plant cells or under the influence [...] Read more.

Mycotoxins are secondary fungal metabolites, toxic to humans, animals and plants. Under the influence of various factors, mycotoxins may undergo modifications of their chemical structure. One of the methods of mycotoxin modification is a transformation occurring in plant cells or under the influence of fungal enzymes. This paper reviews the current knowledge on the natural occurrence of the most important trichothecenes and zearalenone in cereals/cereal products, their metabolism, and the potential toxicity of the metabolites. Only very limited data are available for the majority of the identified mycotoxins. Most studies concern biologically modified trichothecenes, mainly deoxynivalenol-3-glucoside, which is less toxic than its parent compound (deoxynivalenol). It is resistant to the digestion processes within the gastrointestinal tract and is not absorbed by the intestinal epithelium; however, it may be hydrolysed to free deoxynivalenol or deepoxy-deoxynivalenol by the intestinal microflora. Only one zearalenone derivative, zearalenone-14-glucoside, has been extensively studied. It appears to be more reactive than deoxynivalenol-3-glucoside. It may be readily hydrolysed to free zearalenone, and the carbonyl group in its molecule may be easily reduced to α/β-zearalenol and/or other unspecified metabolites. Other derivatives of deoxynivalenol and zearalenone are poorly characterised. Moreover, other derivatives such as glycosides of T-2 and HT-2 toxins have only recently been investigated; thus, the data related to their toxicological profile and occurrence are sporadic. The topics described in this study are crucial to ensure food and feed safety, which will be assisted by the provision of widespread access to such studies and obtained results. Full article

► Show Figures

Figure 1

10 pages, 1229 KiB

Open AccessFeature PaperArticle

Direct (Hetero)Arylation Polymerization of a Spirobifluorene and a Dithienyl-Diketopyrrolopyrrole Derivative: New Donor Polymers for Organic Solar Cells

by Pierre Josse, Sergey Dayneko, Yangqian Zhang, Sylvie Dabos-Seignon, Shiming Zhang, Philippe Blanchard, Gregory C. Welch and Clément Cabanetos

Molecules 2018, 23(4), 962; https://doi.org/10.3390/molecules23040962 - 20 Apr 2018

Cited by 12 | Viewed by 5479

Abstract

The synthesis and preliminary evaluation as donor material for organic photovoltaics of the poly(diketopyrrolopyrrole-spirobifluorene) (PDPPSBF) is reported herein. Prepared via homogeneous and heterogeneous direct (hetero)arylation polymerization (DHAP), through the use of different catalytic systems, conjugated polymers with comparable molecular weights were [...] Read more.

The synthesis and preliminary evaluation as donor material for organic photovoltaics of the poly(diketopyrrolopyrrole-spirobifluorene) (PDPPSBF) is reported herein. Prepared via homogeneous and heterogeneous direct (hetero)arylation polymerization (DHAP), through the use of different catalytic systems, conjugated polymers with comparable molecular weights were obtained. The polymers exhibited strong optical absorption out to 700 nm as thin-films and had appropriate electronic energy levels for use as a donor with PC₇₀BM. Bulk heterojunction solar cells were fabricated giving power conversion efficiencies above 4%. These results reveal the potential of such polymers prepared in only three steps from affordable and commercially available starting materials. Full article

(This article belongs to the Special Issue Direct (Hetero)Arylation: A New Tool for Organic Electronics)

► Show Figures

Graphical abstract

12 pages, 3684 KiB

Open AccessFeature PaperCommunication

Catalytic Enantioselective Addition of Organozirconium Reagents to Aldehydes

by Ricard Solà, Marcos Veguillas, María José González-Soria, Nicholas Carter, M. Angeles Fernández-Ibáñez and Beatriz Maciá

Molecules 2018, 23(4), 961; https://doi.org/10.3390/molecules23040961 - 20 Apr 2018

Cited by 4 | Viewed by 5583

Abstract

A catalytic enantioselective addition reaction of alkylzirconium species to aromatic aldehydes is reported. The reaction, facilitated by a chiral nonracemic diol ligand complex with Ti(OⁱPr)₄, proceeds under mild and convenient conditions, and no premade organometallic reagents are required since [...] Read more.

A catalytic enantioselective addition reaction of alkylzirconium species to aromatic aldehydes is reported. The reaction, facilitated by a chiral nonracemic diol ligand complex with Ti(OⁱPr)₄, proceeds under mild and convenient conditions, and no premade organometallic reagents are required since the alkylzirconium nucleophiles are generated in situ by hydrozirconation of alkenes with the Schwartz reagent. The methodology is compatible with functionalized nucleophiles and a broad range of aromatic aldehydes. Full article

(This article belongs to the Special Issue Stereogenic Centers)

► Show Figures

Graphical abstract

11 pages, 490 KiB

Open AccessArticle

The Chemical Composition and Metabolic Effects of Attalea phalerata Nut Oil in Hyperlipidemic Rats Induced by a High-Fructose Diet

by Débora Da Silva Baldivia, Eliana Janet Sanjinez-Argandonã, Kátia Ávila Antunes, Izabel Cristina Freitas Moraes, Edson Lucas Dos Santos and Kely De Picoli Souza

Molecules 2018, 23(4), 960; https://doi.org/10.3390/molecules23040960 - 20 Apr 2018

Cited by 5 | Viewed by 3989

Abstract

The fatty acids found in nuts are important regulators of the metabolism. These acids are frequently associated with a reduction of serum cholesterol and body fat and a lower risk of developing cardiovascular disease. In this context, the aim of this study was [...] Read more.

The fatty acids found in nuts are important regulators of the metabolism. These acids are frequently associated with a reduction of serum cholesterol and body fat and a lower risk of developing cardiovascular disease. In this context, the aim of this study was to identify and quantify the nut oil fatty acids from Attalea phalerata and investigate their metabolic effects in rats with hyperlipidemia induced by a diet rich in fructose. Oleic and lauric acids were the major compounds found in the A. phalerata nut oil (APNO). Hyperlipidemic rats treated with APNO showed a reduction in the total serum cholesterol similar to those treated with simvastatin, an increased body temperature by 1 °C, and a reduction in the body weight gain and mesenteric depot of white adipose tissue compared to the hyperlipidemic controls rats. There was an increase in the relative liver weight of rats treated with APNO, without, however, any change in the serum markers of hepatic toxicity. In addition, there was an increase in the moisture and lipid content of the feces of the rats treated with APNO compared to the controls. Together, these results suggest that APNO has potential use in health foods and nutritional supplements to control hypercholesterolemia and obesity. Full article

(This article belongs to the Collection Phytochemicals: Biosynthesis, Metabolism and Biological Activities)

► Show Figures

Figure 1

18 pages, 2805 KiB

Open AccessReview

Using Peptidomimetics and Constrained Peptides as Valuable Tools for Inhibiting Protein–Protein Interactions

by Naomi S. Robertson and David R. Spring

Molecules 2018, 23(4), 959; https://doi.org/10.3390/molecules23040959 - 19 Apr 2018

Cited by 68 | Viewed by 10287

Abstract

Protein–protein interactions (PPIs) are tremendously important for the function of many biological processes. However, because of the structure of many protein–protein interfaces (flat, featureless and relatively large), they have largely been overlooked as potential drug targets. In this review, we highlight the current [...] Read more.

Protein–protein interactions (PPIs) are tremendously important for the function of many biological processes. However, because of the structure of many protein–protein interfaces (flat, featureless and relatively large), they have largely been overlooked as potential drug targets. In this review, we highlight the current tools used to study the molecular recognition of PPIs through the use of different peptidomimetics, from small molecules and scaffolds to peptides. Then, we focus on constrained peptides, and in particular, ways to constrain α-helices through stapling using both one- and two-component techniques. Full article

(This article belongs to the Special Issue Protein-Protein Interactions)

► Show Figures

Figure 1

14 pages, 2102 KiB

Open AccessArticle

Anti-Diabetic Effects of Acankoreagenin from the Leaves of Acanthopanax Gracilistylus Herb in RIN-m5F Cells via Suppression of NF-κB Activation

by Man-Xia Lu, Yang Yang, Qin-Peng Zou, Jiao Luo, Bin-Bei Zhang, Xiang-Qian Liu and Eun-Hee Hwang

Molecules 2018, 23(4), 958; https://doi.org/10.3390/molecules23040958 - 19 Apr 2018

Cited by 17 | Viewed by 5006

Abstract

Diabetes mellitus is a chronic degenerative disease that causes long-term complications and represents a serious public health problem. In this manuscript, acankoreagenin isolated from the leaves of Acanthopanax gracilistylus (LAG) is thought to possess excellent anti-diabetic properties. In vitro, anti-diabetic activities were assessed [...] Read more.

Diabetes mellitus is a chronic degenerative disease that causes long-term complications and represents a serious public health problem. In this manuscript, acankoreagenin isolated from the leaves of Acanthopanax gracilistylus (LAG) is thought to possess excellent anti-diabetic properties. In vitro, anti-diabetic activities were assessed based on the inhibitory activities with α-glucosidase (IC₅₀ 13.01 μM), α-amylase (IC₅₀ 30.81 μM), and PTP1B (IC₅₀ 16.39 μM). Acankoreagenin showed better anti-diabetic effects. Then, an investigation was performed to analyze the insulin secretion effects of the insulin-secreting cell line in RIN-m5F cells. It was found that acankoreagenin could increase the insulin release in RIN-m5F cells. It was also found that acankoreagenin reduced NO production, activity of caspase-3, and the reactive oxygen species levels in the cells injured by processing of cytokines. In western blotting, inactivation of NF-κB signaling was confirmed. Acankoreagenin (20 μM) showed a higher I-κBα expression and lower NF-κB expression than the control group and showed a better expression than the positive control L-NAME (1 mM) (p < 0.05). This study demonstrates the anti-diabetic effects of acankoreagenin in vitro and suggests acankoreagenin might offer therapeutic potential for treating diabetes mellitus. Full article

(This article belongs to the Special Issue Medicinal Plants and Diabetes)

► Show Figures

Graphical abstract

18 pages, 2547 KiB

Open AccessArticle

Multi-Response Extraction Optimization Based on Anti-Oxidative Activity and Quality Evaluation by Main Indicator Ingredients Coupled with Chemometric Analysis on Thymus quinquecostatus Celak

by Yan-Li Chang, Meng Shen, Xue-Yang Ren, Ting He, Le Wang, Shu-Sheng Fan, Xiu-Huan Wang, Xiao Li, Xiao-Ping Wang, Xiao-Yi Chen, Hong Sui and Gai-Mei She

Molecules 2018, 23(4), 957; https://doi.org/10.3390/molecules23040957 - 19 Apr 2018

Cited by 11 | Viewed by 4196

Abstract

Thymus quinquecostatus Celak is a species of thyme in China and it used as condiment and herbal medicine for a long time. To set up the quality evaluation of T. quinquecostatus, the response surface methodology (RSM) based on its 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical [...] Read more.

Thymus quinquecostatus Celak is a species of thyme in China and it used as condiment and herbal medicine for a long time. To set up the quality evaluation of T. quinquecostatus, the response surface methodology (RSM) based on its 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was introduced to optimize the extraction condition, and the main indicator components were found through an UPLC-LTQ-Orbitrap MSⁿ method. The ethanol concentration, solid-liquid ratio, and extraction time on optimum conditions were 42.32%, 1:17.51, and 1.8 h, respectively. 35 components having 12 phenolic acids and 23 flavonoids were unambiguously or tentatively identified both positive and negative modes to employ for the comprehensive analysis in the optimum anti-oxidative part. A simple, reliable, and sensitive HPLC method was performed for the multi-component quantitative analysis of T. quinquecostatus using six characteristic and principal phenolic acids and flavonoids as reference compounds. Furthermore, the chemometrics methods (principal components analysis (PCA) and hierarchical clustering analysis (HCA)) appraised the growing areas and harvest time of this herb closely relative to the quality-controlled. This study provided full-scale qualitative and quantitative information for the quality evaluation of T. quinquecostatus, which would be a valuable reference for further study and development of this herb and related laid the foundation of further study on its pharmacological efficacy. Full article

(This article belongs to the Collection Recent Advances in Flavors and Fragrances)

► Show Figures

Figure 1

20 pages, 2124 KiB

Open AccessReview

HIV Resistance Prediction to Reverse Transcriptase Inhibitors: Focus on Open Data

by Olga Tarasova and Vladimir Poroikov

Molecules 2018, 23(4), 956; https://doi.org/10.3390/molecules23040956 - 19 Apr 2018

Cited by 16 | Viewed by 4452

Abstract

Research and development of new antiretroviral agents are in great demand due to issues with safety and efficacy of the antiretroviral drugs. HIV reverse transcriptase (RT) is an important target for HIV treatment. RT inhibitors targeting early stages of the virus-host interaction are [...] Read more.

Research and development of new antiretroviral agents are in great demand due to issues with safety and efficacy of the antiretroviral drugs. HIV reverse transcriptase (RT) is an important target for HIV treatment. RT inhibitors targeting early stages of the virus-host interaction are of great interest for researchers. There are a lot of clinical and biochemical data on relationships between the occurring of the single point mutations and their combinations in the pol gene of HIV and resistance of the particular variants of HIV to nucleoside and non-nucleoside reverse transcriptase inhibitors. The experimental data stored in the databases of HIV sequences can be used for development of methods that are able to predict HIV resistance based on amino acid or nucleotide sequences. The data on HIV sequences resistance can be further used for (1) development of new antiretroviral agents with high potential for HIV inhibition and elimination and (2) optimization of antiretroviral therapy. In our communication, we focus on the data on the RT sequences and HIV resistance, which are available on the Internet. The experimental methods, which are applied to produce the data on HIV-1 resistance, the known data on their concordance, are also discussed. Full article

(This article belongs to the Special Issue Recent Trends on Enzymes Inhibitors and Activators in Drug Research)

► Show Figures

Graphical abstract

Journal Menu

Journal Browser

Molecules, Volume 23, Issue 4 (April 2018) – 277 articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI