Molecules

720 KiB

Open AccessArticle

Characterization of Phosphate Solubilizing Bacteria in Sediments from a Shallow Eutrophic Lake and a Wetland: Isolation, Molecular Identification and Phosphorus Release Ability Determination

by Yichao Qian, Jiyan Shi, Yingxu Chen, Liping Lou, Xinyi Cui, Rukun Cao, Pengfei Li and Jie Tang

Molecules 2010, 15(11), 8518-8533; https://doi.org/10.3390/molecules15118518 - 22 Nov 2010

Cited by 56 | Viewed by 10884

Abstract

The transformation of phosphorus (P) is a major factor of lake eutrophication, and phosphate releasing bacteria play an important role in the release process. Experiments were conducted to investigate P content and characterize phosphate solubilizing bacterial composition at the molecular level in a [...] Read more.

The transformation of phosphorus (P) is a major factor of lake eutrophication, and phosphate releasing bacteria play an important role in the release process. Experiments were conducted to investigate P content and characterize phosphate solubilizing bacterial composition at the molecular level in a shallow eutrophic lake and a wetland. Results showed that P concentrations were relatively high and derived from agricultural runoff and domestic or industrial pollution. Enumeration and molecular identification of these strains indicated that these bacterial groups were abundant in the ecosystem and various kinds of bacteria participated in the phosphorus release process. Twelve phosphate solubilizing bacteria, including eight organic P-solubilizing bacteria (OPBs) and four inorganic P-solubilizing bacteria (IPBs), which belonged to three different families, were isolated and identified. Cupriavidus basilensis was found for the first time to have the ability to mineralize organic P (OP). Laboratory tests on P release ability revealed that IPBs were more effective at releasing P than OPBs. The most efficient IPB strain could accumulate over 170 mg·L^-1 orthophosphate, while the equivalent OPB strain only liberated less than 4 mg·L^-1 orthophosphate in liquid culture. The results obtained from this investigation should help clarify the roles of microorganisms in aquatic systems and the mechanisms of eutrophication. Full article

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286 KiB

Open AccessArticle

Antioxidant, Anti-Inflammatory and Anti-Influenza Properties of Components from Chaenomeles speciosa

by Li Zhang, Yong-Xian Cheng, Ai-Lin Liu, Hai-Di Wang, Ya-Ling Wang and Guan-Hua Du

Molecules 2010, 15(11), 8507-8517; https://doi.org/10.3390/molecules15118507 - 22 Nov 2010

Cited by 84 | Viewed by 14731

Abstract

The fruit of Chaenomeles speciosa is a traditional Chinese medicine used for the treatment of dyspepsia and various inflammatory diseases. In the present study, we evaluated the potential radical scavenging capacity, and activity against nitrous oxide, inflammatory cytokines production and neuramindase (NA) of [...] Read more.

The fruit of Chaenomeles speciosa is a traditional Chinese medicine used for the treatment of dyspepsia and various inflammatory diseases. In the present study, we evaluated the potential radical scavenging capacity, and activity against nitrous oxide, inflammatory cytokines production and neuramindase (NA) of its isolates. The results showed that 3,4-dihydroxybenzoic acid (1) displayed higher inhibitory activities on DPPH and NA with IC₅₀ values of 1.02 mg/mL and 1.27 mg/mL respectively, and quercetin (2) also showed significant inhibitory action on DPPH and NA, with IC₅₀values of 3.82 mg/mL and 1.90 mg/mL. Compounds 1, 2 and methyl 3-hydroxybutanedioic ester (3) could inhibit the production of TNF-a by 22.73%, 33.14% and 37.19% at 5 mg/mL (P < 0.05) compared with the control. In addition, compound 2 was found to be active on the release of IL-6 in RAW264.7 macrophage cells, with an inhibitory rate of 39.79% (P < 0.05). The anti-inflammatory effect of compound 3 is disclosed for the first time in this study. Avian influenza is usually accompanied by virus invasion followed by the occurrence of oxidative stress and serious inflammation, so the multiple effects of the isolates may play a cocktail-like role in the treatment of avian influenza, and C. speciosa components, especially quercetin, might be a potent source for anti-viral and anti-inflammatory agents. Full article

(This article belongs to the Special Issue Antioxidants)

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178 KiB

Open AccessCommunication

Synthesis of Seco-Chlorinated Derivatives of Phenanthroindolizidine Precursors via Friedel-Crafts Reaction

by Songtao Li, Li Han, Jiang Liu, Yihan Hu, Dan Zheng, Yingbo Fu and Xueshi Huang

Molecules 2010, 15(11), 8501-8506; https://doi.org/10.3390/molecules15118501 - 22 Nov 2010

Cited by 2 | Viewed by 5806

Abstract

In the course of synthesizing 3-demethyltylophorine (1) by Lewis acid catalyzed intramolecular Friedel-Crafts reaction starting from N-(3-hydroxy-2,6,7-trimethoxy-phenanthr-9-ylmethyl)-2-chloromethylpyrrolidine, two chlorinated phenanthrene derivatives N-(4,10-dichloro-3-hydroxy-2,6,7-trimethoxyphenanthr-9-ylmethyl)-2-chloromethylpyrrolidine (4) and N-(4-chloro-3-hydroxy-2,6,7-trimethoxyphenanthr-9-ylmethyl)-2-chloromethylpyrrolidine (5) were obtained. The structures of these compounds were determined by spectroscopic analysis. Full article

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Open AccessArticle

Selective Inhibitory Effect of Epigallocatechin-3-gallate on Migration of Vascular Smooth Muscle Cells

by Dong-Wook Han, Mi Hee Lee, Byeong-Ju Kwon, Hye-Lee Kim, Suong-Hyu Hyon and Jong-Chul Park

Molecules 2010, 15(11), 8488-8500; https://doi.org/10.3390/molecules15118488 - 19 Nov 2010

Cited by 11 | Viewed by 9605

Abstract

In order to prevent restenosis after angioplasty or stenting, one of the most popular targets is suppression of the abnormal growth and excess migration of vascular smooth muscle cells (VSMCs) with drugs. However, the drugs also adversely affect vascular endothelial cells (VECs), leading [...] Read more.

In order to prevent restenosis after angioplasty or stenting, one of the most popular targets is suppression of the abnormal growth and excess migration of vascular smooth muscle cells (VSMCs) with drugs. However, the drugs also adversely affect vascular endothelial cells (VECs), leading to the induction of late thrombosis. We have investigated the effect of epigallocatechin-3-gallate (EGCG) on the proliferation and migration of VECs and VSMCs. Both cells showed dose-dependent decrease of viability in response to EGCG while they have different IC₅₀ values of EGCG (VECs, 150 mM and VSMCs, 1050 mM). Incubating both cells with EGCG resulted in significant reduction in cell proliferation irrespective of cell type. The proliferation of VECs were greater affected than that of VSMCs at the same concentrations of EGCG. EGCG exerted differential migration-inhibitory activity in VECs vs. VSMCs. The migration of VECs was not attenuated by 200 mM EGCG, but that of VSMCs was significantly inhibited at the same concentration of EGCG. It is suggested that that EGCG can be effectively used as an efficient drug for vascular diseases or stents due to its selective activity, completely suppressing the proliferation and migration of VSMCs, but not adversely affecting VECs migration in blood vessels. Full article

(This article belongs to the Special Issue Antioxidants)

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299 KiB

Open AccessArticle

The Pharmacokinetics of Raloxifene and Its Interaction with Apigenin in Rat

by Yan Chen, Xiaobin Jia, Jian Chen, Jinyan Wang and Ming Hu

Molecules 2010, 15(11), 8478-8487; https://doi.org/10.3390/molecules15118478 - 18 Nov 2010

Cited by 20 | Viewed by 9690

Abstract

Purpose: Raloxifene is a selective estrogen receptor modulator which is structurally similar to tamoxifen. As flavonoids can interact with raloxifene in vitro, we evaluated the in vivo pharmacokinetics of raloxifene in rats when co-administered with apigenin. Methods: The pharmacokinetics of [...] Read more.

Purpose: Raloxifene is a selective estrogen receptor modulator which is structurally similar to tamoxifen. As flavonoids can interact with raloxifene in vitro, we evaluated the in vivo pharmacokinetics of raloxifene in rats when co-administered with apigenin. Methods: The pharmacokinetics of raloxifene in the absence or presence of apigenin was investigated in rats after different dosage regimens. The plasma concentrations before and after enzymatic hydrolysis were analyzed by HPLC, and the pharmacokinetic profiles of raloxifene administered alone and in combination with apigenin were compared. Results: Co-administration of apigenin with raloxifene in a 1:2 ratio by weight resulted in a 55% and 37% increase in the C_max and AUC of intact raloxifene, respectively. When equal proportions of raloxifene and apigenin (1:1) were administered, the C_max and AUC of intact raloxifene were increased by 173% and 97% respectively. This increase in intact raloxifene was not associated with an increase in total raloxifene (intact plus conjugated raloxifene) because AUC and C_max of total raloxifene when administered alone or in combination with apigenin were found to be similar. The results indicated that apigenin inhibited the glucuronidation and sulfation of raloxifene in the intestine bringing about an increased bioavailability of the drug. Conclusions: The results showed that apigenin decreased the first-pass metabolism of raloxifene but did not increase its absorption from the gastrointestinal tract. Full article

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Open AccessArticle

Antiseptic Activity and Phenolic Constituents of the Aerial Parts of Vitex negundo var. cannabifolia

by Tie-Jun Ling, Wei-Wei Ling, Yuan-Jun Chen, Xiao-Chun Wan, Tao Xia, Xian-Feng Du and Zheng-Zhu Zhang

Molecules 2010, 15(11), 8469-8477; https://doi.org/10.3390/molecules15118469 - 18 Nov 2010

Cited by 47 | Viewed by 11346

Abstract

Four phenolics, salviaplebeiaside (1), γ-tocopherol (2), chrysosplenol-D (4), and isovitexin (5), along with α-tocoquinone (3) and β-sitosterol (6) were isolated from the aerial parts of Vitex negundo var. [...] Read more.

Four phenolics, salviaplebeiaside (1), γ-tocopherol (2), chrysosplenol-D (4), and isovitexin (5), along with α-tocoquinone (3) and β-sitosterol (6) were isolated from the aerial parts of Vitex negundo var. cannabifolia. The isolation was performed using bio-assay tracking experiments. The structures of compounds 1-5 were established by spectroscopic means. The antibacterial activities of the compounds were assessed against Escherichia coli, Bacillus subtilis, Micrococcus tetragenus and Pseudomonas fluorescens. Chrysosplenol-D (4) exhibited activities against all the four spoilage microorganisms. Full article

(This article belongs to the Special Issue Phenolics and Polyphenolics)

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Open AccessReview

Sorption Speciation of Lanthanides/Actinides on Minerals by TRLFS, EXAFS and DFT Studies: A Review

by Xiaoli Tan, Ming Fang and Xiangke Wang

Molecules 2010, 15(11), 8431-8468; https://doi.org/10.3390/molecules15118431 - 17 Nov 2010

Cited by 146 | Viewed by 16718

Abstract

Lanthanides/actinides sorption speciation on minerals and oxides by means of time resolved laser fluorescence spectroscopy (TRLFS), extended X-ray absorption fine structure spectroscopy (EXAFS) and density functional theory (DFT) is reviewed in the field of nuclear disposal safety research. The theoretical aspects of the [...] Read more.

Lanthanides/actinides sorption speciation on minerals and oxides by means of time resolved laser fluorescence spectroscopy (TRLFS), extended X-ray absorption fine structure spectroscopy (EXAFS) and density functional theory (DFT) is reviewed in the field of nuclear disposal safety research. The theoretical aspects of the methods are concisely presented. Examples of recent research results of lanthanide/actinide speciation and local atomic structures using TRLFS, EXAFS and DFT are discussed. The interaction of lanthanides/actinides with oxides and minerals as well as their uptake are also of common interest in radionuclide chemistry. Especially the sorption and inclusion of radionuclides into several minerals lead to an improvement in knowledge of minor components in solids. In the solid-liquid interface, the speciation and local atomic structures of Eu(III), Cm(III), U(VI), and Np(IV/VI) in several natural and synthetic minerals and oxides are also reviewed and discussed. The review is important to understand the physicochemical behavior of lanthanides/actinides at a molecular level in the natural environment. Full article

(This article belongs to the Special Issue Radiochemistry)

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Open AccessArticle

Microwave-Assisted Synthesis of Novel 2,3-Dihydro-4-Pyridinones

by Bahjat A. Saeed, Rita S. Elias and Wisam A. Radhi

Molecules 2010, 15(11), 8425-8430; https://doi.org/10.3390/molecules15118425 - 17 Nov 2010

Cited by 6 | Viewed by 5518

Abstract

Novel 2,3-dihydro-4-pyridinones were synthesized via the reaction of curcumin and primary amines or amine acetates under microwave irradiation. Montmorillonite K-10 was used as a catalyst. Reaction times did not exceed 120 s. The structures of the compounds were established by elemental analysis and [...] Read more.

Novel 2,3-dihydro-4-pyridinones were synthesized via the reaction of curcumin and primary amines or amine acetates under microwave irradiation. Montmorillonite K-10 was used as a catalyst. Reaction times did not exceed 120 s. The structures of the compounds were established by elemental analysis and from their mass, ¹H- and ¹³C-NMR spectra. Full article

(This article belongs to the Section Organic Chemistry)

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456 KiB

Open AccessReview

Combining the Benefits of Homogeneous and Heterogeneous Catalysis with Tunable Solvents and Nearcritical Water

by Ali Z. Fadhel, Pamela Pollet, Charles L. Liotta and Charles A. Eckert

Molecules 2010, 15(11), 8400-8424; https://doi.org/10.3390/molecules15118400 - 16 Nov 2010

Cited by 105 | Viewed by 17148

Abstract

The greatest advantage of heterogeneous catalysis is the ease of separation, while the disadvantages are often limited activity and selectivity. We report solvents that use tunable phase behavior to achieve homogeneous catalysis with ease of separation. Tunable solvents are homogeneous mixtures of water [...] Read more.

The greatest advantage of heterogeneous catalysis is the ease of separation, while the disadvantages are often limited activity and selectivity. We report solvents that use tunable phase behavior to achieve homogeneous catalysis with ease of separation. Tunable solvents are homogeneous mixtures of water or polyethylene glycol with organics such as acetonitrile, dioxane, and THF that can be used for homogeneously catalyzed reactions. Modest pressures of a soluble gas, generally CO₂, achieve facile post-reaction heterogeneous separation of products from the catalyst. Examples shown here are rhodium-catalyzed hydroformylation of 1-octene and p-methylstyrene and palladium catalyzed C-O coupling to produce o-tolyl-3,5-xylyl ether and 3,5-di-tert-butylphenol. Both were successfully carried out in homogeneous tunable solvents followed by separation efficiencies of up to 99% with CO₂ pressures of 3 MPa. Further examples in tunable solvents are enzyme catalyzed reactions such as kinetic resolution of rac-1-phenylethyl acetate and hydrolysis of 2-phenylethyl acetate (2PEA) to 2-phenylethanol (2PE). Another tunable solvent is nearcritical water (NCW), whose unique properties offer advantages for developing sustainable alternatives to traditional processes. Some examples discussed are Friedel-Crafts alkylation and acylation, hydrolysis of benzoate esters, and water-catalyzed deprotection of N-Boc-protected amine compounds. Full article

(This article belongs to the Special Issue Heterogeneous Catalysis)

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173 KiB

Open AccessArticle

Comparative Analysis of Headspace Volatiles of Chinese Rosa rugosa

by Li-Guo Feng, Chen Chen, Li-Xia Sheng, Ping Liu, Jun Tao, Jia-Le Su and Lan-Yong Zhao

Molecules 2010, 15(11), 8390-8399; https://doi.org/10.3390/molecules15118390 - 16 Nov 2010

Cited by 40 | Viewed by 9711

Abstract

The floral headspace compounds of Chinese Rosa rugosa germplasms that were isolated by an automated headspace sampler with built-in trap, and followed by gas chromatography-mass spectrometry for identification and quantification. Up to 33 volatile compounds were identified from the 23 rose germplasms, including [...] Read more.

The floral headspace compounds of Chinese Rosa rugosa germplasms that were isolated by an automated headspace sampler with built-in trap, and followed by gas chromatography-mass spectrometry for identification and quantification. Up to 33 volatile compounds were identified from the 23 rose germplasms, including nine alcohols, five esters, three alkanes, 10 terpenes, three aldehydes, two ketones, and one ether. The main floral components identified were 2-phenylethanol, β-citronellol, ethanol, and n-hexane. ‘xizi’, ‘miaofengshan’, ‘xiangciguo’, and ‘tangbai’ contained the highest amounts of 2-phenylethanol at 84.66 μg·g^-1, β-citronellol at 70.98 μg·g^-1, ethanol at 83.87 μg·g^-1, and n-hexane at 18.23 μg·g^-1, respectively. ‘Rongchengyesheng’, ‘tanghong’, ‘xizi’, ‘miaofengshan’, and ‘baizizhi’ could be considered good materials for extracting rose oil and breeding new cultivars. Full article

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Open AccessArticle

Anti-Neoplastic Effects of Gallic Acid, a Major Component of Toona sinensis Leaf Extract, on Oral Squamous Carcinoma Cells

by Yi-Chen Chia, Ranjan Rajbanshi, Colonya Calhoun and Robert H. Chiu

Molecules 2010, 15(11), 8377-8389; https://doi.org/10.3390/molecules15118377 - 16 Nov 2010

Cited by 113 | Viewed by 11855

Abstract

Extract of Toona sinensis (TS) has been reported to have various effects on cultured cell lines, including anti-proliferative activity in cancer cells. We have studied the effects of TS on various human oral squamous carcinoma cell lines (HOSCC), including UM1, UM2, [...] Read more.

Extract of Toona sinensis (TS) has been reported to have various effects on cultured cell lines, including anti-proliferative activity in cancer cells. We have studied the effects of TS on various human oral squamous carcinoma cell lines (HOSCC), including UM1, UM2, SCC-4, and SCC-9. These cell lines were treated with TS leaf extract and screened for viability, apoptosis, necrosis, and apoptotic gene expression. Normal human oral keratinocytes (NHOK) served as a control for cytotoxic assays. Viability of TS-treated HOSCC was reduced, whereas that of NHOK was not affected. FACScan analysis revealed that the leaf extract induced apoptosis or a combination of apoptosis and necrosis, depending on cell type. Microarray and semi-quantitative RT-PCR analysis for apoptotic-related gene expression revealed that 3,4,5-trihydroxybenzoic acid (gallic acid, one of the major bioactive compounds purified from TS extract) up-regulated pro-apoptotic genes such TNF-α, TP53BP2, and GADD45A, and down-regulated the anti-apoptotic genes Survivin and cIAP1, resulting in cell death. This study suggests that gallic acid, the major bioactive compound present, is responsible for the anti-neoplastic effect of Toona sinensis leaf extract. Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessArticle

Median Lethal Dose, Antimalarial Activity, Phytochemical Screening and Radical Scavenging of Methanolic Languas galanga Rhizome Extract

by Abdulelah H. Al-Adhroey, Zurainee M. Nor, Hesham M. Al-Mekhlafi and Rohela Mahmud

Molecules 2010, 15(11), 8366-8376; https://doi.org/10.3390/molecules15118366 - 16 Nov 2010

Cited by 20 | Viewed by 10452

Abstract

The methanolic extract of Languas galanga rhizomes was investigated for antimalarial activity against Plasmodium berghei (NK65) infections in mice. The median lethal dose was determined to ascertain the safety of the extract in ICR mice of both sexes. The antimalarial activities during early [...] Read more.

The methanolic extract of Languas galanga rhizomes was investigated for antimalarial activity against Plasmodium berghei (NK65) infections in mice. The median lethal dose was determined to ascertain the safety of the extract in ICR mice of both sexes. The antimalarial activities during early and established infections, as well as the prophylactic activity were evaluated. Phytochemical screening and radical scavenging activity of the extract were also investigated to elucidate the possible mechanism of the antimalarial properties. The acute oral toxicity (LD₅₀) of Languas galanga extract in mice was established to be 4,998 mg/kg. The extract of Languas galanga rhizomes demonstrated significant antiplasmodial activity in all the three models of the antimalarial evaluations. Phytochemical screening revealed the presence of some vital antiplasmodial constituents such as terpenoids and flavonoids. The extract also exhibited a moderate capacity to scavenge the free radicals. The rhizome extract of Languas galanga thus possesses antimalarial activity, which explains the rational usage of this plant in traditional Malaysian medicine. Full article

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Open AccessArticle

A Novel 18-Norclerodane Diterpenoid from the Roots of Tinospora sagittata var. yunnanensis

by Xiang-Zhong Huang, Chun-Mei Cheng, Yun Dai, Guang-Miao Fu, Jun-Ming Guo, Yan Yin and Hui Liang

Molecules 2010, 15(11), 8360-8365; https://doi.org/10.3390/molecules15118360 - 16 Nov 2010

Cited by 13 | Viewed by 8228

Abstract

A novel 18-nor-clerodane diterpenoid named sagitone (1) was isolated from the 95% ethanol extract of dry roots of Tinospora sagittata var. yunnanensis together with the five known diterpenoids columbin (2), palmatoside C (3), fibleucin (4), [...] Read more.

A novel 18-nor-clerodane diterpenoid named sagitone (1) was isolated from the 95% ethanol extract of dry roots of Tinospora sagittata var. yunnanensis together with the five known diterpenoids columbin (2), palmatoside C (3), fibleucin (4), tinophylloloside (5) and epitinophylloloside (6). The structure of the new compound 1 was determined based on MS, IR, 1D and 2D NMR spectral data. The compounds 1~6 did not show significant cytotoxic activity against cancer cell lines K562 and HL-60. Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessArticle

Pancreatic Lipase Inhibition by C-Glycosidic Flavones Isolated from Eremochloa ophiuroides

by Eun Mi Lee, Seung Sik Lee, Byung Yeoup Chung, Jae-Young Cho, In Chul Lee, So Ra Ahn, Soo Jeung Jang and Tae Hoon Kim

Molecules 2010, 15(11), 8251-8259; https://doi.org/10.3390/molecules15118251 - 16 Nov 2010

Cited by 75 | Viewed by 9989

Abstract

Activity-guided fractionation of a methanolic extract of the leaves of Eremochloa ophiuroides (centipede grass) using a pancreatic lipase inhibitory assay led to the isolation and identification of a new C-glycosidic flavone, luteolin 6-C-b-D-boivinopyranoside (1), as well as eight [...] Read more.

Activity-guided fractionation of a methanolic extract of the leaves of Eremochloa ophiuroides (centipede grass) using a pancreatic lipase inhibitory assay led to the isolation and identification of a new C-glycosidic flavone, luteolin 6-C-b-D-boivinopyranoside (1), as well as eight known compounds. The structures of these compounds were established on the basis of interpretation of their spectroscopic data. Among these isolates, the C-glycosidic flavones 1–5 showed potent inhibitory effects on pancreatic lipase, with IC₅₀ values ranging from 18.5 ± 2.6 to 50.5 ± 3.9 mM. Full article

(This article belongs to the Collection Bioactive Compounds)

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Open AccessArticle

Synthesis, Structures and Properties of Cu(II) and Mn(II) Complexes with 1,10-Phenanthroline-2-carboxylic acid and 2,2’-Bipyridine Ligands

by Jingya Sun and Huanzhi Xu

Molecules 2010, 15(11), 8349-8359; https://doi.org/10.3390/molecules15118349 - 15 Nov 2010

Cited by 15 | Viewed by 6477

Abstract

Four new 2,2’-bipyridine and 1,10-phenanthroline complexes, namely [Mn(phenca)₂]·(H₂O)₂ (1), [Cu₄(phen)₄(OH^-)₄(H₂O)₂](DMF)₄(ClO₄^-)₄(H₂O) (2), [Cu₂ [...] Read more.

Four new 2,2’-bipyridine and 1,10-phenanthroline complexes, namely [Mn(phenca)₂]·(H₂O)₂ (1), [Cu₄(phen)₄(OH^-)₄(H₂O)₂](DMF)₄(ClO₄^-)₄(H₂O) (2), [Cu₂(2,2-bipy)₂(C₂O₄^2-)(H₂O)₂(NO₃)₂] (3) and [Cu(2,2-bipy)₂(ClO₄^-)](ClO₄^-) (4) (2,2’-bpy = 2,2’-bipyridine, Hphenca = 1,10-phenanthroline-2-carboxylic acid) have been synthesized by a hydrothermal reaction. The products were characterized by elemental analysis, infrared spectroscopy and X-ray crystal diffraction. While strong hydrogen bonds play central roles in the formation of the 3D structure, the combined influence of the weak interactions such as π···π interactions is also evident in the structures. A preliminary investigation on the ion exchange properties of the complexes is presented. Full article

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Open AccessArticle

Synthesis and Properties of Chiral Thioureas Bearing an Additional Function at a Remote Position Tethered by a 1,5-Disubstituted Triazole

by Kiyosei Takasu, Takumi Azuma, Iderbat Enkhtaivan and Yoshiji Takemoto

Molecules 2010, 15(11), 8327-8348; https://doi.org/10.3390/molecules15118327 - 15 Nov 2010

Cited by 6 | Viewed by 7589

Abstract

The synthesis and properties of multifunctional thioureas bearing a variety of functional groups at a position remote from the thiourea moiety are described. A 1,5-disubstituted triazole tether connected with a thiourea and another functional group was synthesized via ruthenium catalyzed Huisgen cycloaddition. We [...] Read more.

The synthesis and properties of multifunctional thioureas bearing a variety of functional groups at a position remote from the thiourea moiety are described. A 1,5-disubstituted triazole tether connected with a thiourea and another functional group was synthesized via ruthenium catalyzed Huisgen cycloaddition. We demonstrate the utility of the synthetic thioureas as asymmetric catalysts and probes for the mechanistic elucidation of the course of the Michael reaction of an α,β-unsaturated imide Full article

(This article belongs to the Special Issue Bifunctional Catalysis)

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Open AccessArticle

Catalytic Asymmetric Synthesis of Both Enantiomers of 4‑Substituted 1,4-Dihydropyridines with the Use of Bifunctional Thiourea-Ammonium Salts Bearing Different Counterions

by Kohzo Yoshida, Tsubasa Inokuma, Kiyosei Takasu and Yoshiji Takemoto

Molecules 2010, 15(11), 8305-8326; https://doi.org/10.3390/molecules15118305 - 15 Nov 2010

Cited by 28 | Viewed by 7112

Abstract

Organoammonium salts composed of a Brønsted acid and an anilinothiourea promoted the Michael addition of β-keto esters and α,β-unsaturated aldehydes in the presence of primary amines to give functionalized 1,4-dihydropyridines enantioselectively. With the use of the different Brønsted acids such as DFA and [...] Read more.

Organoammonium salts composed of a Brønsted acid and an anilinothiourea promoted the Michael addition of β-keto esters and α,β-unsaturated aldehydes in the presence of primary amines to give functionalized 1,4-dihydropyridines enantioselectively. With the use of the different Brønsted acids such as DFA and HBF₄ with the same bifunctional thiourea, both enantiomers of 4-substituted 1,4-dihydropyridine were synthesized from the same starting materials. Full article

(This article belongs to the Special Issue Bifunctional Catalysis)

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Open AccessArticle

Towards the Development of Synthetic Routes Using Theoretical Calculations: An Application of In Silico Screening to 2,6-Dimethylchroman-4-one

by Kenji Hori, Hirotaka Sadatomi, Atsuo Miyamoto, Takaaki Kuroda, Michinori Sumimoto and Hidetoshi Yamamoto

Molecules 2010, 15(11), 8289-8304; https://doi.org/10.3390/molecules15118289 - 15 Nov 2010

Cited by 9 | Viewed by 7576

Abstract

This study describes an attempt to develop a synthetic route using theoretical calculations, i.e., in silico synthesis route development. The KOSP program created four potential synthetic routes for generating 2,6-dimethylchroman-4-one. In silico screening of these four synthetic routes was then performed. In [...] Read more.

This study describes an attempt to develop a synthetic route using theoretical calculations, i.e., in silico synthesis route development. The KOSP program created four potential synthetic routes for generating 2,6-dimethylchroman-4-one. In silico screening of these four synthetic routes was then performed. In silico screening involves theoretical analysis of synthetic routes prior to actual experimental work. A synthetic route using the Mitsunobu reaction had already been reported by Hoddgets et al. Theoretical investigations were also conducted on two S_NAr reactions as well as a Michael reaction before they were examined experimentally. In silico screening using DFT calculations indicated that only the Michael reaction was likely to produce the target. Experimental work confirmed that the target was obtained in a yield of 76.4% using the Michael reaction. The other two routes, except for the Mitsunobu reaction, failed to generate the target. Our results demonstrate that theoretical calculations can be used to narrow down the number of experiments that need to be conducted when developing novel synthetic routes. Full article

(This article belongs to the Special Issue From Computational Chemistry to Complex Networks)

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Open AccessArticle

MimoDB: a New Repository for Mimotope Data Derived from Phage Display Technology

by Beibei Ru, Jian Huang, Ping Dai, Shiyong Li, Zhongkui Xia, Hui Ding, Hao Lin, Feng-Biao Guo and Xianlong Wang

Molecules 2010, 15(11), 8279-8288; https://doi.org/10.3390/molecules15118279 - 15 Nov 2010

Cited by 43 | Viewed by 11540

Abstract

Peptides selected from phage-displayed random peptide libraries are valuable in two aspects. On one hand, these peptides are candidates for new diagnostics, therapeutics and vaccines. On the other hand, they can be used to predict the networks or sites of protein-protein interactions. MimoDB, [...] Read more.

Peptides selected from phage-displayed random peptide libraries are valuable in two aspects. On one hand, these peptides are candidates for new diagnostics, therapeutics and vaccines. On the other hand, they can be used to predict the networks or sites of protein-protein interactions. MimoDB, a new repository for these peptides, was developed, in which 10,716 peptides collected from 571 publications were grouped into 1,229 sets. Besides peptide sequences, other important information, such as the target, template, library and complex structure, was also included. MimoDB can be browsed and searched through a user-friendly web interface. For computational biologists, MimoDB can be used to derive customized data sets and benchmarks, which are useful for new algorithm development and tool evaluation. For experimental biologists, their results can be searched against the MimoDB database to exclude possible target-unrelated peptides. The MimoDB database is freely accessible at http://immunet.cn/mimodb/. Full article

(This article belongs to the Special Issue Phage Display of Combinatorial Libraries)

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Open AccessReview

Radiolabeled Small Molecule Protein Kinase Inhibitors for Imaging with PET or SPECT

by Justin W. Hicks, Henry F. VanBrocklin, Alan A. Wilson, Sylvain Houle and Neil Vasdev

Molecules 2010, 15(11), 8260-8278; https://doi.org/10.3390/molecules15118260 - 15 Nov 2010

Cited by 56 | Viewed by 12855

Abstract

Imaging protein kinase expression with radiolabeled small molecule inhibitors has been actively pursued to monitor the clinical potential of targeted therapeutics and treatments as well as to determine kinase receptor density changes related to disease progression. The goal of the present review is [...] Read more.

Imaging protein kinase expression with radiolabeled small molecule inhibitors has been actively pursued to monitor the clinical potential of targeted therapeutics and treatments as well as to determine kinase receptor density changes related to disease progression. The goal of the present review is to provide an overview of the breadth of radiolabeled small molecules that have been synthesized to target intracellular protein kinases, not only for imaging in oncology, but also for other areas of interest, particularly the central nervous system. Considerable radiotracer development has focused on imaging receptor tyrosine kinases of growth factors, protein kinases A, B and C, and glycogen synthase kinase–3β. Design considerations, structural attributes and relevant biological results are summarized. Full article

(This article belongs to the Special Issue Radiochemistry)

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Open AccessArticle

Phenolic Compounds from Merremia umbellata subsp. orientalis and Their Allelopathic Effects on Arabidopsis Seed Germination

by Jian Yan, Hai-Hong Bi, Yong-Zhu Liu, Mei Zhang, Zhong-Yu Zhou and Jian-Wen Tan

Molecules 2010, 15(11), 8241-8250; https://doi.org/10.3390/molecules15118241 - 12 Nov 2010

Cited by 22 | Viewed by 11431

Abstract

A bioassay-directed phytochemical study was carried out to investigate potential allelochemicals of the invasive plant Merremia umbellata subsp. orientalis (Hall. f.). Eight phenolic compounds, including a salicylic acid (SA)-derived new natural product, SA 2-O-β-D-(3',6'-dicaffeoyl)-glucopyranoside (1), and seven known ones [...] Read more.

A bioassay-directed phytochemical study was carried out to investigate potential allelochemicals of the invasive plant Merremia umbellata subsp. orientalis (Hall. f.). Eight phenolic compounds, including a salicylic acid (SA)-derived new natural product, SA 2-O-β-D-(3',6'-dicaffeoyl)-glucopyranoside (1), and seven known ones 2-8 were isolated and identified from two bioactive sub-fractions of the acetone extract of this plant. The structure of new compound 1 was established by spectral and chemical methods. The potential allelopathic effects of these compounds at 0.5 and 1.0 mM concentrations on the germination of Arabidopsis seeds were tested. Results showed that 2 remarkably inhibited seed germination at concentrations as low as 0.5 mM. Compound 3 only moderately inhibited seed germination at 0.5 mM, but displayed strong inhibitory bioactivity at 1.0 mM concentration. Compounds 4 and 5 showed only slight inhibitory bioactivity at 1.0 mM, while the other compounds showed no obvious inhibitory effects. Full article

(This article belongs to the Section Natural Products Chemistry)

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325 KiB

Open AccessCommunication

Study on Suitability of KOD DNA Polymerase for Enzymatic Production of Artificial Nucleic Acids Using Base/Sugar Modified Nucleoside Triphosphates

by Masayasu Kuwahara, Yuuki Takano, Yuuya Kasahara, Hiroki Nara, Hiroaki Ozaki, Hiroaki Sawai, Akio Sugiyama and Satoshi Obika

Molecules 2010, 15(11), 8229-8240; https://doi.org/10.3390/molecules15118229 - 12 Nov 2010

Cited by 28 | Viewed by 8714

Abstract

Recently, KOD and its related DNA polymerases have been used for preparing various modified nucleic acids, including not only base-modified nucleic acids, but also sugar-modified ones, such as bridged/locked nucleic acid (BNA/LNA) which would be promising candidates for nucleic acid drugs. However, thus [...] Read more.

Recently, KOD and its related DNA polymerases have been used for preparing various modified nucleic acids, including not only base-modified nucleic acids, but also sugar-modified ones, such as bridged/locked nucleic acid (BNA/LNA) which would be promising candidates for nucleic acid drugs. However, thus far, reasons for the effectiveness of KOD DNA polymerase for such purposes have not been clearly elucidated. Therefore, using mutated KOD DNA polymerases, we studied here their catalytic properties upon enzymatic incorporation of nucleotide analogues with base/sugar modifications. Experimental data indicate that their characteristic kinetic properties enabled incorporation of various modified nucleotides. Among those KOD mutants, one achieved efficient successive incorporation of bridged nucleotides with a 2′-ONHCH₂CH₂-4′ linkage. In this study, the characteristic kinetic properties of KOD DNA polymerase for modified nucleoside triphosphates were shown, and the effectiveness of genetic engineering in improvement of the enzyme for modified nucleotide polymerization has been demonstrated. Full article

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223 KiB

Open AccessArticle

Crucial Role of Selenium in the Virucidal Activity of Benzisoselenazol-3(2H)-ones and Related Diselenides

by Magdalena Pietka-Ottlik, Piotr Potaczek, Egbert Piasecki and Jacek Mlochowski

Molecules 2010, 15(11), 8214-8228; https://doi.org/10.3390/molecules15118214 - 12 Nov 2010

Cited by 55 | Viewed by 11379

Abstract

Various N-substituted benzisoselenazol-3(2H)-ones and their non-selenium-containing analogues have been synthesized and tested against selected viruses (HHV-1, EMCV and VSV) to determine the extent to which selenium plays a role in antiviral activity. The data presented here show that the presence [...] Read more.

Various N-substituted benzisoselenazol-3(2H)-ones and their non-selenium-containing analogues have been synthesized and tested against selected viruses (HHV-1, EMCV and VSV) to determine the extent to which selenium plays a role in antiviral activity. The data presented here show that the presence of selenium is crucial for the antiviral properties of benzisoselenazol-3(2H)-ones since their isostructural analogues having different groups but lacking selenium either did not show any antiviral activity or their activity was substantially lower. The open-chain analogues of benzisoselenazol-3(2H)-ones—diselenides also exhibited high antiviral activity while selenides and disulfides were completely inactive towards model viruses. Full article

(This article belongs to the Special Issue Antivirals)

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Open AccessArticle

A Highly Efficient Bismuth Salts-Catalyzed Route for the Synthesis of α-Aminophosphonates

by Antara Banik, Sahil Batta, Debasish Bandyopadhyay and Bimal K. Banik

Molecules 2010, 15(11), 8205-8213; https://doi.org/10.3390/molecules15118205 - 12 Nov 2010

Cited by 32 | Viewed by 7127

Abstract

A convenient synthesis of different types of α-amino phosphonates via one-pot solvent-free three component reactions of aldehydes, amines and phosphites catalyzed by bismuth salts has been investigated. Bismuth triflate is found to be the most effective catalyst for this reaction. Full article

(This article belongs to the Special Issue Organobismuth Chemistry)

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Open AccessArticle

Chemical Constituents of the Bark of Dipteryx alata Vogel, an Active Species against Bothrops jararacussu Venom

by Pilar Puebla, Yoko Oshima-Franco, Luiz M. Franco, Marcio G. Dos Santos, Renata V. da Silva, Leandro Rubem-Mauro and Arturo San Feliciano

Molecules 2010, 15(11), 8193-8204; https://doi.org/10.3390/molecules15118193 - 12 Nov 2010

Cited by 49 | Viewed by 13181

Abstract

The effect of four sub-extracts prepared from the lyophilized hydroalcoholic bark of Dipteryx alata (Leguminosae-Papilionoideae) dissolved in a methanol-water (80:20) mixture through a liquid-liquid partition procedure has been investigated against the neuromuscular blockade of the venom of the snake Bothrops jararacussu. The [...] Read more.

The effect of four sub-extracts prepared from the lyophilized hydroalcoholic bark of Dipteryx alata (Leguminosae-Papilionoideae) dissolved in a methanol-water (80:20) mixture through a liquid-liquid partition procedure has been investigated against the neuromuscular blockade of the venom of the snake Bothrops jararacussu. The active CH₂Cl₂ sub-extract has been extensively analyzed for its chemical constituents, resulting in the isolation of four lupane-type triterpenoids: lupeol (1), lupenone (2), 28-hydroxylup-20(29)-en-3-one (3), betulin (4), nine isoflavonoids: 8-O-methylretusin (5), 7-hydroxy-5,6,4’-trimethoxyisoflavone (6), afrormosin (8), 7-hydroxy-8,3’,4’-trimethoxyisoflavone (9), 7,3’-dihydroxy-8,4’-dimethoxyisoflavone (10), odoratin (11), 7,8,3’-trihydroxy-4’-methoxyisoflavone (13), 7,8,3’-trihydroxy-6,4’-dimethoxyisoflavone (15), dipteryxin (17), one chalcone: isoliquiritigenin (7), one aurone: sulfuretin (14) and three phenolic compounds: vanillic acid (12),vanillin (16), and protocatechuic acid (18). Their chemical structures were elucidated on the basis of spectroscopic analysis, including HRMS, 1D- and 2D-NMR techniques. Full article

(This article belongs to the Section Natural Products Chemistry)

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188 KiB

Open AccessArticle

Analysis of Protein Pathway Networks Using Hybrid Properties

by Lei Chen, Tao Huang, Xiao-He Shi, Yu-Dong Cai and Kuo-Chen Chou

Molecules 2010, 15(11), 8177-8192; https://doi.org/10.3390/molecules15118177 - 12 Nov 2010

Cited by 49 | Viewed by 10190

Abstract

Given a protein-forming system, i.e., a system consisting of certain number of different proteins, can it form a biologically meaningful pathway? This is a fundamental problem in systems biology and proteomics. During the past decade, a vast amount of information on different [...] Read more.

Given a protein-forming system, i.e., a system consisting of certain number of different proteins, can it form a biologically meaningful pathway? This is a fundamental problem in systems biology and proteomics. During the past decade, a vast amount of information on different organisms, at both the genetic and metabolic levels, has been accumulated and systematically stored in various specific databases, such as KEGG, ENZYME, BRENDA, EcoCyc and MetaCyc. These data have made it feasible to address such an essential problem. In this paper, we have analyzed known regulatory pathways in humans by extracting different (biological and graphic) features from each of the 17,069 protein-formed systems, of which 169 are positive pathways, i.e., known regulatory pathways taken from KEGG; while 16,900 were negative, i.e., not formed as a biologically meaningful pathway. Each of these protein-forming systems was represented by 352 features, of which 88 are graph features and 264 biological features. To analyze these features, the “Minimum Redundancy Maximum Relevance” and the “Incremental Feature Selection” techniques were utilized to select a set of 22 optimal features to query whether a protein-forming system is able to form a biologically meaningful pathway or not. It was found through cross-validation that the overall success rate thus obtained in identifying the positive pathways was 79.88%. It is anticipated that, this novel approach and encouraging result, although preliminary yet, may stimulate extensive investigations into this important topic. Full article

(This article belongs to the Special Issue From Computational Chemistry to Complex Networks)

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Open AccessArticle

5,6-Didehydroginsenosides from the Roots of Panax notoginseng

by Jian-Bo Wan, Qing-Wen Zhang, Si-Jia Hong, Jia Guan, Wen-Cai Ye, Shao-Ping Li, Ming-Yuen Simon Lee and Yi-Tao Wang

Molecules 2010, 15(11), 8169-8176; https://doi.org/10.3390/molecules15118169 - 11 Nov 2010

Cited by 25 | Viewed by 7342

Abstract

Two minor novel dammarane-type saponins—5,6-didehydroginsenoside Rd (1) and 5,6-didehydroginsenoside Rb1 (2)—were isolated from the dried roots of Panax notoginseng along with sixteen known saponins. The structures of the new compounds were elucidated on the basis of spectroscopic and chemical methods. Full article

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Open AccessArticle

Oligomerization of 3,5-Dimethyl Benzyl Alcohol Promoted by Clay: Experimental and Theoretical Study

by José Antonio Morales-Serna, Luis E. López-Duran, Miguel Castro, Luis E. Sansores, Mikhail Zolotukhin and Manuel Salmón

Molecules 2010, 15(11), 8156-8168; https://doi.org/10.3390/molecules15118156 - 11 Nov 2010

Cited by 8 | Viewed by 8902

Abstract

Linear oligomerization of 3,5-dimethyl benzyl alcohol is induced by a montmorillonite clay (Tonsil Optimum Extra), producing 1,3,5,7-tetramethyl-9,10-dihydro-anthracene, which, by loss of protons results in the product 1,3,5,7-tetramethylanthracene. It was also found that the compounds 4-(3´,5´-dimethylbenzyl)-1,3,5,7-tetramethyl-9,10-dihydroanthracece and 4-(3´,5´-dimethylbenzyl)-1,3,5,7-tetra-methylanthracene were formed from 1,3,5,7-tetramethyl-9,10-dihydroanthracene. 1,3,5,7-Tetramethylanthryl radical [...] Read more.

Linear oligomerization of 3,5-dimethyl benzyl alcohol is induced by a montmorillonite clay (Tonsil Optimum Extra), producing 1,3,5,7-tetramethyl-9,10-dihydro-anthracene, which, by loss of protons results in the product 1,3,5,7-tetramethylanthracene. It was also found that the compounds 4-(3´,5´-dimethylbenzyl)-1,3,5,7-tetramethyl-9,10-dihydroanthracece and 4-(3´,5´-dimethylbenzyl)-1,3,5,7-tetra-methylanthracene were formed from 1,3,5,7-tetramethyl-9,10-dihydroanthracene. 1,3,5,7-Tetramethylanthryl radical cation was formed from 1,3,5,7-tetramethyl-9,10-dihydroanthracene; it was characterized by Electronic Paramagnetic Resonance (EPR). On the other hand, a theoretical analysis was performed, allowing the rationalization of the observed products and some of the key reaction steps. Full article

(This article belongs to the Section Organic Chemistry)

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Open AccessArticle

2-Chlorophenyl Zinc Bromide: A Convenient Nucleophile for the Mannich-Related Multicomponent Synthesis of Clopidogrel and Ticlopidine

by Isabelle Aillaud, Caroline Haurena, Erwan Le Gall, Thierry Martens and Gino Ricci

Molecules 2010, 15(11), 8144-8155; https://doi.org/10.3390/molecules15118144 - 11 Nov 2010

Cited by 18 | Viewed by 10775

Abstract

A methodological study devoted to the Mannich-like multicomponent synthesis of the antiplatelet agent (±)‑clopidogrel (7) and the ethyl ester analogue 6 is described. The process involves the formation of 2-chlorophenyl zinc bromide (2) and its subsequent reaction with an [...] Read more.

A methodological study devoted to the Mannich-like multicomponent synthesis of the antiplatelet agent (±)‑clopidogrel (7) and the ethyl ester analogue 6 is described. The process involves the formation of 2-chlorophenyl zinc bromide (2) and its subsequent reaction with an alkyl glyoxylate and 4,5,6,7-tetrahydrothieno[3,2-c]pyridine (3). We demonstrate that the organozinc reagent 2 also constitutes a very convenient nucleophile for the multicomponent synthesis of the benzylamine core of ticlopidine (9). Full article

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17 KiB

Open AccessCorrection

Al-Salahi, R. Synthesis and Reactivity of [1,2,4]Triazolo-annelated Quinazolines. Molecules 2010, 15, 7016-7034

by Rashad A. Al-Salahi and Detlef Geffken

Molecules 2010, 15(11), 8143; https://doi.org/10.3390/molecules15118143 - 10 Nov 2010

Cited by 2 | Viewed by 6357

Abstract

The authors wish to make the following corrections to the paper published in Molecules [1]: The authorship of the paper is changed to Rashad A. Al-Salahi and Detlef Geffken. [...] Full article

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Molecules, Volume 15, Issue 11 (November 2010) – 71 articles , Pages 7509-8533

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