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181 KiB

Open AccessArticle

Chemical Composition, and Antioxidant and Antimicrobial Activities of Essential Oil of Phyllostachys heterocycla cv. Pubescens Varieties from China

by Yong-Chun Jin, Ke Yuan and Jing Zhang

Molecules 2011, 16(5), 4318-4327; https://doi.org/10.3390/molecules16054318 - 24 May 2011

Cited by 23 | Viewed by 7657

Abstract

The essential oils of Phyllostachys heterocycla cv. Pubescens, Phyllostachys heterocycla cv. Gracilis, Phyllostachys heterocycla cv. Heterocycla and Phyllostachys kwangsiensis leaves were obtained by steam distillation. Their chemical components were separated and identified by gas chromatography/mass spectrometry (GC/MS). Meanwhile, the effect of scavenging free radicals of essential oil was assayed by using the DPPH·method with Trolox^® as control to evaluate their antioxidant capacities. Gram-positive (Staphyloccocus aureus) and Gram-negative (Escherichia coli) were selected as the indicator microorganisms to evaluate the antimicrobial activity. Antimicrobial properties were estimated by the agar diffusion method. The results show that 63 components were separated and identified by GC/MS from these varieties of bamboo leaves. cis-3-Hexenol, whose content in cv. Pubescens, Gracilis, Heterocycla and Ph. kwangsiensis was 27.11%, 24.62%, 30.51% and 34.65%, respectively, was the main constituent. The relative content of alcohol compounds in these varieties of essential oils ranged from 39.8% to 46.64%. All of the bamboo leaf essential oils possessed certain antioxidant capacity; the corresponding IC₅₀ values were 3.1622, 4.9353, 4.2473, and 5.4746 μL/mL, respectively. Essential oils of all tested bamboo spp. were active against Staphylococcus epidermidis and E. coli, showing a positive correlation with the essential oil concentration of 50.42-300 μL/mL. The results indicated there were no significant differences among three varieties and the related species with respect to their antioxidant and antimicrobial activities. This paper provides evidence for studying the essential composition from different varieties of bamboo leaves. Full article

(This article belongs to the Collection Bioactive Compounds)

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191 KiB

Open AccessArticle

Synthesis, and Antitumor Activity of Some N1-(Coumarin-7-yl) Amidrazones and Related Congeners

by Mohammad S. Mustafa, Mustafa M. El-Abadelah, Malek A. Zihlif, Randa G. Naffa and Mohammad S. Mubarak

Molecules 2011, 16(5), 4305-4317; https://doi.org/10.3390/molecules16054305 - 24 May 2011

Cited by 40 | Viewed by 7194

Abstract

A series of new N1-(coumarin-7-yl)amidrazones incorporating N-piperazines and related congeners were synthesized by reacting the hydrazonoyl chloride derived from 7-amino-4-methylcoumarin with the appropriate piperazines. The chemical structures of the newly prepared compounds were supported by elemental analyses, ¹H-NMR, ¹³C-NMR, and ESI-HRMS spectral data. The antitumor activity of the newly synthesized compounds was evaluated. Among all the compounds tested, 7-{2-[1-(4-(1-benzyl-2-ethyl-4-nitro-1H-imidazol-5-yl)piperazin-1-yl)-2-oxopropylidene]hydrazinyl}-4-methyl-2H-chromen-2-one (3n) was the most potent against MCF-7 and K562 cells, with IC₅₀ values of 20.2 and 9.3 μM, respectively. Full article

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278 KiB

Open AccessArticle
Transformation of Geniposide into Genipin by Immobilized β-Glucosidase in a Two-Phase Aqueous-Organic System
by Yi-Shun Yang, Tong Zhang, Shai-Cheng Yu, Yue Ding, Li-Ying Zhang, Chen Qiu and Duo Jin

Molecules 2011, 16(5), 4295-4304; https://doi.org/10.3390/molecules16054295 - 24 May 2011
Cited by 42 | Viewed by 7716
Abstract
Genipin is the bioactive compound of geniposide and a natural cross-linking agent. In order to improve the preparation process of genipin, the hydrolysis of geniposide to genipin by immobilized β-glucosidase in an aqueous-organic two-phase system was studied. β-Glucosidase was immobilized by the crosslinking-embedding [...] Read more.

Genipin is the bioactive compound of geniposide and a natural cross-linking agent. In order to improve the preparation process of genipin, the hydrolysis of geniposide to genipin by immobilized β-glucosidase in an aqueous-organic two-phase system was studied. β-Glucosidase was immobilized by the crosslinking-embedding method using sodium alginate as the carrier. The optimum reaction temperature, pH value and time were 55 °C, 4.5 and 2.5 h, respectively. To reduce genipin hydrolysis and byproduct production the reaction was carried out in an aqueous-organic two-phase system comprising ethyl acetate and sodium acetate buffer. The product was analyzed by HPLC, UV, IR, and NMR. The yield of genipin was 47.81% and its purity was over 98% (HPLC). Full article

(This article belongs to the Section Natural Products Chemistry)

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506 KiB

Open AccessArticle
A Screening of a Library of T7 Phage-Displayed Peptide Identifies E2F-4 as an Etoposide-Binding Protein
by Mihoko Takami, Yoichi Takakusagi, Kouji Kuramochi, Senko Tsukuda, Satoko Aoki, Kengo Morohashi, Keisuke Ohta, Susumu Kobayashi, Kengo Sakaguchi and Fumio Sugawara

Molecules 2011, 16(5), 4278-4294; https://doi.org/10.3390/molecules16054278 - 24 May 2011
Cited by 12 | Viewed by 7634
Abstract
Etoposide (VP-16) is an anti-tumor compound that targets topoisomerase II (top II). In this study, we have identified an alternative binding protein of etoposide by screening a library of T7 phage-displayed peptides. After four rounds of selection using a biotinylated etoposide derivative immobilized [...] Read more.

Etoposide (VP-16) is an anti-tumor compound that targets topoisomerase II (top II). In this study, we have identified an alternative binding protein of etoposide by screening a library of T7 phage-displayed peptides. After four rounds of selection using a biotinylated etoposide derivative immobilized on a streptavidin-coated plate, T7 phage particles that display a 16-mer peptide NSSASSRGNSSSNSVY (ETBP16) or a 10-mer NSLRKYSKLK (ETBP10) were enriched with the ratio of 40 or 11 out of the 69 clones, respectively. Binding of etoposide to these peptides was confirmed by surface plasmon resonance (SPR) analysis, which showed ETBP16 and ETBP10 to have a kinetic constant of 4.85 × 10⁻⁵ M or 6.45 × 10⁻⁵ M, respectively. ETBP16 displays similarity with the ser-rich domain in E2F-4, a transcription factor in cell cycle-regulated genes, suggesting that etoposide might interact with E2F-4 via this domain. SPR analysis confirmed the specific binding of etoposide to recombinant E2F-4 is in the order of 10⁻⁵ M. Furthermore, etoposide was shown to inhibit luciferase reporter gene expression mediated by the heterodimeric E2F-4/DP complex. Taken together, our results suggest that etoposide directly binds to E2F-4 and inhibits subsequent gene transcription mediated by heterodimeric E2F-4/DP complexes in the nucleus. Full article

(This article belongs to the Collection Bioactive Compounds)

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468 KiB

Open AccessArticle
Mangiferin, an Anti-HIV-1 Agent Targeting Protease and Effective against Resistant Strains
by Rui-Rui Wang, Yue-Dong Gao, Chun-Hui Ma, Xing-Jie Zhang, Cheng-Gang Huang, Jing-Fei Huang and Yong-Tang Zheng

Molecules 2011, 16(5), 4264-4277; https://doi.org/10.3390/molecules16054264 - 24 May 2011
Cited by 64 | Viewed by 11466
Abstract
The anti-HIV-1 activity of mangiferin was evaluated. Mangiferin can inhibit HIV-1_Ⅲ_B induced syncytium formation at non-cytotoxic concentrations, with a 50% effective concentration (EC₅₀) at 16.90 μM and a therapeutic index (TI) above 140. Mangiferin also showed good activities in [...] Read more.

The anti-HIV-1 activity of mangiferin was evaluated. Mangiferin can inhibit HIV-1_Ⅲ_B induced syncytium formation at non-cytotoxic concentrations, with a 50% effective concentration (EC₅₀) at 16.90 μM and a therapeutic index (TI) above 140. Mangiferin also showed good activities in other laboratory-derived strains, clinically isolated strains and resistant HIV-1 strains. Mechanism studies revealed that mangiferin might inhibit the HIV-1 protease, but is still effective against HIV peptidic protease inhibitor resistant strains. A combination of docking and pharmacophore methods clarified possible binding modes of mangiferin in the HIV-1 protease. The pharmacophore model of mangiferin consists of two hydrogen bond donors and two hydrogen bond acceptors. Compared to pharmacophore features found in commercially available drugs, three pharmacophoric elements matched well and one novel pharmacophore element was observed. Moreover, molecular docking analysis demonstrated that the pharmacophoric elements play important roles in binding HIV-1 protease. Mangiferin is a novel nonpeptidic protease inhibitor with an original structure that represents an effective drug development strategy for combating drug resistance. Full article

(This article belongs to the Special Issue Antivirals)

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399 KiB

Open AccessArticle
Cytotoxicity and Pro-Apoptotic Activity of 2,2´-Bis[4,5-bis(4-hydroxybenzyl)-2-(4-hydroxyphenyl)cyclopent-4-en-1,3-dione], a Phenolic Cyclopentenedione Isolated from the Cyanobacterium Strain Nostoc sp. str. Lukešová 27/97
by Jan Vacek, Jan Hrbáč, Jiří Kopecký and Jitka Vostálová

Molecules 2011, 16(5), 4254-4263; https://doi.org/10.3390/molecules16054254 - 23 May 2011
Cited by 9 | Viewed by 6716
Abstract
The cytotoxicity of the polyphenol 2,2´-bis[4,5-bis(4-hydroxybenzyl)-2-(4-hydroxyphenyl)cyclopent-4-en-1,3-dione], nostotrebin 6 (NOS-6), was tested under in vitro conditions using mouse fibroblasts (BALB/c cells). Identification of NOS-6 and its uptake into fibroblasts was examined by multi-stage mass spectrometry analysis with the following fragmentation pattern: MS (m/z [...] Read more.

The cytotoxicity of the polyphenol 2,2´-bis[4,5-bis(4-hydroxybenzyl)-2-(4-hydroxyphenyl)cyclopent-4-en-1,3-dione], nostotrebin 6 (NOS-6), was tested under in vitro conditions using mouse fibroblasts (BALB/c cells). Identification of NOS-6 and its uptake into fibroblasts was examined by multi-stage mass spectrometry analysis with the following fragmentation pattern: MS (m/z) [M+H]⁺ 799.1 → MS² 399.1 → MS³ 305.1 → MS⁴ 277.1. Using several cell viability assays, the IC₅₀ of NOS-6 after 24 h incubation was found to be 8.48 ± 0.16/12.15 ± 1.96 µM (neutral red/MTT assay) which was higher than that of doxorubicin. It was found that NOS-6 is capable of inducing both types of cell death, apoptosis and necrosis in a dose-dependent manner. The biological activities of the cyclopentenediones and preliminary data on NOS-6 cytotoxicity are discussed. Full article

(This article belongs to the Collection Bioactive Compounds)

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111 KiB

Open AccessArticle
In Vitro Antibacterial and Antifungal Activity of Lavandula x intermedia Emeric ex Loisel. ‘Budrovka’
by Biljana Blazekovic, Gordana Stanic, Stjepan Pepeljnjak and Sanda Vladimir-Knezevic

Molecules 2011, 16(5), 4241-4253; https://doi.org/10.3390/molecules16054241 - 23 May 2011
Cited by 20 | Viewed by 7809
Abstract
This study aimed to evaluate the in vitro antibacterial and antifungal activities of Lavandula x intermedia Emeric ex Loisel. ‘Budrovka’, an indigenous Croatian cultivar of lavandin. For that purpose the activity of ethanolic extracts of flowers, inflorescence stalks and leaves against thirty one [...] Read more.

This study aimed to evaluate the in vitro antibacterial and antifungal activities of Lavandula x intermedia Emeric ex Loisel. ‘Budrovka’, an indigenous Croatian cultivar of lavandin. For that purpose the activity of ethanolic extracts of flowers, inflorescence stalks and leaves against thirty one strains of bacteria, yeasts, dermatophytes and moulds were studied using both the agar well diffusion and broth dilution assays. Among the investigated extracts found to be effective against a broad spectrum of microorganisms, the flower extract was considered to be the most potent one. Linalool and rosmarinic acid, as the most abundant constituents found, are very likely major contributors to the observed antimicrobial effects. The results suggest that flowers of lavandin ‘Budrovka’ could serve as a rich source of natural terpene and polyphenol antimicrobial agents. Full article

(This article belongs to the Section Natural Products Chemistry)

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702 KiB

Open AccessArticle
The Effect of Ultrasound on the Functional Properties of Wheat Gluten
by Haihua Zhang, Irakoze P. Claver, Ke-Xue Zhu and Huiming Zhou

Molecules 2011, 16(5), 4231-4240; https://doi.org/10.3390/molecules16054231 - 23 May 2011
Cited by 96 | Viewed by 8483
Abstract
In this study, the effect of ultrasound on the foaming and emulsifying properties of wheat gluten as well as its electrophoretic and rheology properties were investigated. The foam capacity and foam stability of ultrasound treated wheat gluten proteins gradually increased as the treatment [...] Read more.

In this study, the effect of ultrasound on the foaming and emulsifying properties of wheat gluten as well as its electrophoretic and rheology properties were investigated. The foam capacity and foam stability of ultrasound treated wheat gluten proteins gradually increased as the treatment power increased, and were more pronounced at 100% power level. Excluding those of the raw wheat gluten, the lowest emulsifying capacity values and emulsifying stability were obtained with the samples ultrasound treated at 60% power level. In general, ultrasound treatment did not cause major changes on the protein electrophoretic patterns of gluten samples at the power levels used. Ultrasound affected the storage and the loss moduli with typical U-shape alteration. Full article

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418 KiB

Open AccessReview
Synthesis, Properties Characterization and Applications of Various Organobismuth Compounds
by Jingfei Luan, Lingyan Zhang and Zhitian Hu

Molecules 2011, 16(5), 4191-4230; https://doi.org/10.3390/molecules16054191 - 20 May 2011
Cited by 45 | Viewed by 9988
Abstract
Organobismuth chemistry was emphasized in this review article due to the low price, low toxicity and low radioactivity characteristics of bismuth. As an environmentally-friendly class of organometallic compounds, different types of organobismuth compounds have been used in organic synthesis, catalysis, materials, etc. The [...] Read more.

Organobismuth chemistry was emphasized in this review article due to the low price, low toxicity and low radioactivity characteristics of bismuth. As an environmentally-friendly class of organometallic compounds, different types of organobismuth compounds have been used in organic synthesis, catalysis, materials, etc. The synthesis and property characterization of many organobismuth compounds had been summarized. This review article also presented a survey of various applications of organobismuth compounds in organic transformations, as reagents or catalysts. The reactivity, reaction pathways and mechanisms of reactions with organobismuths were discussed. Less common and limiting aspects of organobismuth compounds were also briefly mentioned. Full article

(This article belongs to the Special Issue Organometallic Chemistry)

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210 KiB

Open AccessArticle
Involvement of Carbohydrate, Protein and Phenylanine Ammonia Lyase in Up-Regulation of Secondary Metabolites in Labisia pumila under Various CO₂ and N₂ Level
by Mohd Hafiz Ibrahim and Hawa Z.E. Jaafar

Molecules 2011, 16(5), 4172-4190; https://doi.org/10.3390/molecules16054172 - 20 May 2011
Cited by 47 | Viewed by 8965
Abstract
A split plot factorial 2 × 3 experiment was designed to examine and characterize the relationships among secondary metabolites (total phenolics, TP; total flavonoids, TF), carbohydrate content, C/N ratio, protein synthesis and L–phenylalanine ammonia lyase (PAL; EC 4.3.1.5) activity in the Malaysian medicinal [...] Read more.

A split plot factorial 2 × 3 experiment was designed to examine and characterize the relationships among secondary metabolites (total phenolics, TP; total flavonoids, TF), carbohydrate content, C/N ratio, protein synthesis and L–phenylalanine ammonia lyase (PAL; EC 4.3.1.5) activity in the Malaysian medicinal herb Labisia pumila (Blume) Fern-Vill. under different CO₂ concentrations (400 = ambient and 1,200 µmol mol⁻¹CO₂) and three levels of nitrogen fertilization (0, 90 and 270 kg N ha⁻¹) for 15 weeks. The interaction between CO₂and nitrogen levels imposed a significant impact on plant secondary metabolite production, protein, PAL activity and fructose levels. Highest TP and TF were recorded under 1,200 µmol mol⁻¹ CO₂ when N fertilizer was not applied; lowest values were obtained at 400 µmol mol⁻¹ CO₂ fertilized with the highest N level. Concurrently, fructose contents increased tremendously. Increase in fructose content might also enhance erythose-4-phosphate production (substrate for lignin and phenolic compounds), which shares a common precursor transdalolase in the pentose phosphate pathway. PAL activity was noted to be highest under 1,200 µmol mol⁻¹ CO₂ + 0 kg N ha⁻¹coinciding with subsequent recording of the lowest protein content. The results implied that the increase in plant secondary metabolites production under the tested conditions might be due to diversion of phenylalanine for protein synthesis to production of secondary metabolites. It was also found that the sucrose to starch ratio was also high under high levels of nitrogen fertilization, indicating an enhanced sucrose phosphate synthase activity (SPS; EC 2.4.1.14) under such condition. Full article

(This article belongs to the Section Natural Products Chemistry)

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158 KiB

Open AccessCommunication
A Regioselective Synthesis of E-Guggulsterone
by Jungyeob Ham, Jungwook Chin and Heonjoong Kang

Molecules 2011, 16(5), 4165-4171; https://doi.org/10.3390/molecules16054165 - 20 May 2011
Cited by 12 | Viewed by 6201
Abstract
We have successfully prepared E-guggulsterone from 16,17-epoxy-pregnenolone in 84% yield over two steps via a hydrazine reduction and Oppenhauer oxidation. Additionally, isomerization was induced by heat, light (hn) and acid catalysis to convert E- guggulsterone into the corresponding Z isomer. Full article

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456 KiB

Open AccessReview
Aminolevulinic Acid (ALA) as a Prodrug in Photodynamic Therapy of Cancer
by Małgorzata Wachowska, Angelika Muchowicz, Małgorzata Firczuk, Magdalena Gabrysiak, Magdalena Winiarska, Małgorzata Wańczyk, Kamil Bojarczuk and Jakub Golab

Molecules 2011, 16(5), 4140-4164; https://doi.org/10.3390/molecules16054140 - 19 May 2011
Cited by 212 | Viewed by 21836
Abstract
Aminolevulinic acid (ALA) is an endogenous metabolite normally formed in the mitochondria from succinyl-CoA and glycine. Conjugation of eight ALA molecules yields protoporphyrin IX (PpIX) and finally leads to formation of heme. Conversion of PpIX to its downstream substrates requires the activity of [...] Read more.

Aminolevulinic acid (ALA) is an endogenous metabolite normally formed in the mitochondria from succinyl-CoA and glycine. Conjugation of eight ALA molecules yields protoporphyrin IX (PpIX) and finally leads to formation of heme. Conversion of PpIX to its downstream substrates requires the activity of a rate-limiting enzyme ferrochelatase. When ALA is administered externally the abundantly produced PpIX cannot be quickly converted to its final product - heme by ferrochelatase and therefore accumulates within cells. Since PpIX is a potent photosensitizer this metabolic pathway can be exploited in photodynamic therapy (PDT). This is an already approved therapeutic strategy making ALA one of the most successful prodrugs used in cancer treatment. Full article

(This article belongs to the Special Issue Prodrugs)

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257 KiB

Open AccessArticle
Effects of Agronomic Practices on Volatile Composition of Hyssopus officinalis L. Essential Oils
by Armando Moro, Amaya Zalacain, Jorge Hurtado de Mendoza and Manuel Carmona

Molecules 2011, 16(5), 4131-4139; https://doi.org/10.3390/molecules16054131 - 19 May 2011
Cited by 31 | Viewed by 10040
Abstract
The chemical composition of Hyssopus officinalis (Lamiaceae) essential oil grown in southeastern Spain was analyzed by GC-MS. Due to the high relevance of this species in the world market, the study is focused on chemical heterogeneity of different oil batches and their extraction [...] Read more.

The chemical composition of Hyssopus officinalis (Lamiaceae) essential oil grown in southeastern Spain was analyzed by GC-MS. Due to the high relevance of this species in the world market, the study is focused on chemical heterogeneity of different oil batches and their extraction yield, cultivated under irrigation and non-irrigation conditions and with different harvesting dates. All essential oil samples have two main terpene compounds which are pinocamphone and iso-pinocamphone, accounting for approximately 35–40% of the total oil content. Other relevant compounds were identified, with β-pinene, which accounted for 10–17% contribution to the total composition, standing out. Significant differences between their volatile composition have been observed between treatments, being limonene, (E)-β-ocimene, pinocarveol, α-pinene and β-phellandrene the compounds that contributed most to the discrimination. It was also observed that the irrigation period is the most favourable for the cultivation of hyssop in this region, specially for batch 7 which gives the highest extraction yield and the best EO quality. Full article

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399 KiB

Open AccessArticle
The Influence of t-Butyl and Cyclododecyl Substitution on Ethylene/1-Hexene Copolymerization Using Ansa-Fluorenylamidodimethyltitanium Derivatives
by Patcharaporn Kaivalchatchawal, Piyasan Praserthdam, Yuuichi Sogo, Zhengguo Cai, Takeshi Shiono and Bunjerd Jongsomjit

Molecules 2011, 16(5), 4122-4130; https://doi.org/10.3390/molecules16054122 - 19 May 2011
Cited by 2 | Viewed by 6316
Abstract
In the present study, copolymerization of ethylene and 1-hexene was conducted with a series of ansa-fluorenylamidodimethyltitanium complexes, including [t-BuNSiMe₂Flu]TiMe₂ (complex 1), [cyclododecylNSiMe₂Flu]TiMe₂ (complex 2) and [t-BuNSiMe₂(2,7-t-Bu₂Flu)]TiMe₂ [...] Read more.

In the present study, copolymerization of ethylene and 1-hexene was conducted with a series of ansa-fluorenylamidodimethyltitanium complexes, including [t-BuNSiMe₂Flu]TiMe₂ (complex 1), [cyclododecylNSiMe₂Flu]TiMe₂ (complex 2) and [t-BuNSiMe₂(2,7-t-Bu₂Flu)]TiMe₂ (complex 3), activated by MMAO. The effect of these catalysts on catalytic behavior, namely activity, molecular weight and monomer reactivity ratios, has been investigated. The results showed that all of them acted by a single site polymerization mechanism and the molecular weight distribution is independent of catalyst structure. Based on the study, it revealed that the introduction of a t-butyl at the 2,7 position on the fluorenyl ligand is able to enhance both catalytic activity and copolymer molecular weight more than introducing a cyclododecyl on the amine, which is probably associated with the electronic effect exerted by the t-butyl substituent. The comonomer incorporation content was controllable over a wide range by adjusting the comonomer feed ratio. Moreover, referring to monomer reactivity ratio exploration, it seems that the substitution on the ansa-fluorenylamidodimethyltitanium complex tends to hinder the insertion of 1-hexene into the polymer chain, leading to the highest 1-hexene content for traditional complex 1. Full article

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318 KiB

Open AccessArticle
Solid-Phase Synthesis of Arylpiperazine Derivatives and Implementation of the Distributed Drug Discovery (D3) Project in the Search for CNS Agents
by Paweł Zajdel, Joanna Król, Katarzyna Grychowska, Maciej Pawłowski, Gilles Subra, Gaël Nomezine, Jean Martinez, Grzegorz Satała, Andrzej J. Bojarski, Ziniu Zhou, Martin J. O’Donnell and William L. Scott

Molecules 2011, 16(5), 4104-4121; https://doi.org/10.3390/molecules16054104 - 19 May 2011
Cited by 3 | Viewed by 7289
Abstract
We have successfully implemented the concept of Distributed Drug Discovery (D3) in the search for CNS agents. Herein, we demonstrate, for the first time, student engagement from different sites around the globe in the development of new biologically active compounds. As an outcome [...] Read more.

We have successfully implemented the concept of Distributed Drug Discovery (D3) in the search for CNS agents. Herein, we demonstrate, for the first time, student engagement from different sites around the globe in the development of new biologically active compounds. As an outcome we have synthesized a 24-membered library of arylpiperazine derivatives targeted to 5-HT_1A and 5-HT_2A receptors. The synthesis was simultaneously performed on BAL-MBHA-PS resin in Poland and the United States, and on BAL-PS-SynPhase Lanterns in France. The D3 project strategy opens the possibility of obtaining potent 5-HT_1A/5-HT_2A agents in a distributed fashion. While the biological testing is still centralized, this combination of distributed synthesis with screening will enable a D3 network of students world-wide to participate, as part of their education, in the synthesis and testing of this class of biologically active compounds. Full article

(This article belongs to the Section Medicinal Chemistry)

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149 KiB

Open AccessArticle
Synthesis of the Key Intermediate of Coenzyme Q₁₀
by Fan-Song Mu, Meng Luo, Yu-Jie Fu, Xuan Zhang, Ping Yu and Yuan-Gang Zu

Molecules 2011, 16(5), 4097-4103; https://doi.org/10.3390/molecules16054097 - 18 May 2011
Cited by 9 | Viewed by 7350
Abstract
(2’E)-1-(3-methyl-4-p-toluenesulfonyl-2-butene)-6-methyl-2,3,4,5-tetramethoxybenzene (4) is the key intermediate in the synthesis of coenzyme Q₁₀ via a coupling reaction with solanesyl bromide. In this paper, we report a simple and effective synthesis of compound 4, starting with the [...] Read more.

(2’E)-1-(3-methyl-4-p-toluenesulfonyl-2-butene)-6-methyl-2,3,4,5-tetramethoxybenzene (4) is the key intermediate in the synthesis of coenzyme Q₁₀ via a coupling reaction with solanesyl bromide. In this paper, we report a simple and effective synthesis of compound 4, starting with the readily available and inexpensive precursors p-toluenesulfonyl chloride (TsCl) and isoprene to obtain (2E)-1-p-toluenesulfonyl-2-methyl-4-hydroxy-2-butene (3) by addition, esterification and hydrolysis. Application of the Friedel-Crafts alkylation to compound 3, followed by the addition of 2,3,4,5-tetramethoxytoluene (TeMT), assembled the two parts into compound 4. The key parameters of each reaction were optimized at the same time, and the four total operations needed to produced compound 4 had a 27.9% overall yield under the optimized conditions. The structures of the compounds were characterized by ¹H-NMR, IR and MS. This alternative process has the potential to be used for large-scale process. Full article

(This article belongs to the Section Organic Chemistry)

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221 KiB

Open AccessArticle
Chemical Composition, Antioxidant and Antimicrobial Activity of Pericarpium Citri Reticulatae Essential Oil
by Bei Gao, Yulong Chen, Mingwei Zhang, Yujuan Xu and Siyi Pan

Molecules 2011, 16(5), 4082-4096; https://doi.org/10.3390/molecules16054082 - 18 May 2011
Cited by 29 | Viewed by 7772
Abstract
The chemical composition, antioxidant and antimicrobial activity of Pericarpium Citri Reticulatae (PCR) essential oil obtained using an improved Clevenger type apparatus were studied. Among the five different PCRs examined the highest yield of essential oil was found in Chachi 2004 (harvested and stored [...] Read more.

The chemical composition, antioxidant and antimicrobial activity of Pericarpium Citri Reticulatae (PCR) essential oil obtained using an improved Clevenger type apparatus were studied. Among the five different PCRs examined the highest yield of essential oil was found in Chachi 2004 (harvested and stored in 2004) and the lowest in Chachi 2008 (harvested and stored in 2008). Fifty three different volatile compounds were determined, including terpenic hydrocarbons, alcohols, aldehydes, ketones and esters. D-limonene, one of terpenes, was the major constituent in PCR. The antioxidant capacity of PCR essential oil varied considerably with the duration of storage time, and the oil from Chachi 1994 has the strongest ferric-reducing antioxidant power. In addition, the essential oil possessed varying degrees of antimicrobial activity against Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus), except Streptococcus faecalis, while had no effect on Gram-negative bacteria (Escherichia coli, Enterobacter cloacae). Full article

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182 KiB

Open AccessArticle
Copper(I)-Catalyzed [ 3+ 2] Cycloaddition of 3-Azidoquinoline-2,4(1H,3H)-diones with Terminal Alkynes
by Stanislav Kafka, Sylvia Hauke, Arjana Salcinovic, Otto Soidinsalo, Damijana Urankar and Janez Kosmrlj

Molecules 2011, 16(5), 4070-4081; https://doi.org/10.3390/molecules16054070 - 18 May 2011
Cited by 6 | Viewed by 5862
Abstract
3-Azidoquinoline-2,4(1H,3H)-diones 1, which are readily available from 4-hydroxyquinolin-2(1H)-ones 4 via 3-chloroquinoline-2,4(1H,3H)-diones 5, afford, in copper(I)-catalyzed [3 + 2] cycloaddition reaction with terminal acetylenes, 1,4-disubstituted 1,2,3-triazoles 3 in moderate to excellent yields. [...] Read more.

3-Azidoquinoline-2,4(1H,3H)-diones 1, which are readily available from 4-hydroxyquinolin-2(1H)-ones 4 via 3-chloroquinoline-2,4(1H,3H)-diones 5, afford, in copper(I)-catalyzed [3 + 2] cycloaddition reaction with terminal acetylenes, 1,4-disubstituted 1,2,3-triazoles 3 in moderate to excellent yields. The structures of compounds 3 were confirmed by ¹H and ¹³C-NMR spectroscopy, combustion analyses and mass spectrometry. Full article

(This article belongs to the Section Organic Chemistry)

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196 KiB

Open AccessArticle
Synthesis of Ginkgolic Acid Analogues and Evaluation of Their Molluscicidal Activity
by Peng Zhang, Jiahu Pan, Wanxing Duan, Xuedong Li, Yao Zhang, Yibiao Zhou, Qingwu Jiang, Zuohua Mao and Peizhong Yu

Molecules 2011, 16(5), 4059-4069; https://doi.org/10.3390/molecules16054059 - 17 May 2011
Cited by 7 | Viewed by 6288
Abstract
Based on the molluscicidal activity of ginkgolic acids (GAs) isolated from Ginkgo biloba L, a series of Z/E isomers of GA analogues were prepared and evaluated for their molluscicidal activities against the host snail Oncomelania hupensis. The results and analysis [...] Read more.

Based on the molluscicidal activity of ginkgolic acids (GAs) isolated from Ginkgo biloba L, a series of Z/E isomers of GA analogues were prepared and evaluated for their molluscicidal activities against the host snail Oncomelania hupensis. The results and analysis of the structure-activity relationship revealed that the E-isomers showed better molluscicidal activities than their Z-isomers. Molluscicidal activities decreased with the shortening of the alkenyl chain lengths. Full article

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539 KiB

Open AccessArticle
The Effects of Co-Treatment of 9-cis-Retinoic Acid and 15-Deoxy-Δ (12,14)-prostaglandin J2 on Microglial Activation
by Pei-Chien Hsu, Huey-Jen Tsay, Thomas J. Montine and Feng-Shiun Shie

Molecules 2011, 16(5), 4045-4058; https://doi.org/10.3390/molecules16054045 - 17 May 2011
Cited by 1 | Viewed by 6214
Abstract
Microglial activation plays an important role in the regulation of neuronal function and contributes to the development of neurodegeneration in Alzheimer’s disease (AD). Activation of nuclear peroxisome proliferator-activated receptor gamma (PPARγ) by an endogenous agonist, 15-deoxy-Δ(12,14)-prostaglandin J2 (15d-PGJ2), has been shown to be [...] Read more.

Microglial activation plays an important role in the regulation of neuronal function and contributes to the development of neurodegeneration in Alzheimer’s disease (AD). Activation of nuclear peroxisome proliferator-activated receptor gamma (PPARγ) by an endogenous agonist, 15-deoxy-Δ(12,14)-prostaglandin J2 (15d-PGJ2), has been shown to be beneficial in many diseases with aberrant immune responses. Here, we report that co-treatment with 15d-PGJ2 and its synergistic partner, 9-cis-retinoic acid (RA), may modulate, but not abolish, microglial immune response activated by β-amyloid (Aβ) and interferon gamma (IFNγ). The co-treatment of RA and 15d-PGJ2 inhibited Aβ/IFNγ-activated immune response in primary microglia, as evidenced by suppressed expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2); and the effect was not affected by treatment with a PPARγ antagonist, GW9662. Data suggest that PPARγ activation may not contribute to the anti-inflammatory properties of the co-treatment. The co-treatment promoted microglial Aβ clearance in cultures; and the effect can be prevented by blocking PPARγ activation using GW9662. The effects of the co-treatment on Aβ clearance may be PPARγ-dependent. Intriguingly, secretion of microglial pro-nerve growth factor (pro-NGF) was inhibited by Aβ/IFNg treatment in a dose-dependent manner, suggesting that secretion of microglial pro-NGF may not contribute to the Ab/IFNg-activated microglial immune response. Taken together, the co-treatment may be beneficial for AD therapy; however, our data suggest that multiple mechanisms may underlie the beneficial effects of the co-treatment and are not limited to PPARγ activation only. Full article

(This article belongs to the Special Issue Neuroactive Compounds)

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258 KiB

Open AccessArticle
Dehydration of (Perfluoroalkyl)tetramethylcyclopentenols
by Jan Čermák, Thu Huong Nguyen Thi, Jaroslav Včelák and Alena Krupková

Molecules 2011, 16(5), 4031-4044; https://doi.org/10.3390/molecules16054031 - 17 May 2011
Cited by 2 | Viewed by 5482
Abstract
(Perfluoroalkyl) tetramethylcyclopentenols (alkyl = n-butyl, n-hexyl, n-octyl) were dehydrated to a complex mixture of endo, endo-(perfluoroalkyl) tetramethyl-cyclopentadienes and their endo-, exo-isomers. It was found in preliminary screening experiments that the best reagent for this transformation, giving an 89% [...] Read more.

(Perfluoroalkyl) tetramethylcyclopentenols (alkyl = n-butyl, n-hexyl, n-octyl) were dehydrated to a complex mixture of endo, endo-(perfluoroalkyl) tetramethyl-cyclopentadienes and their endo-, exo-isomers. It was found in preliminary screening experiments that the best reagent for this transformation, giving an 89% yield of isomeric product mixture, was P₂O₅ in benzene at 80-90 °C. Products were characterized on the basis of their mass spectra and retention time information, and some peaks in the mass spectra were identified from their molecular fragments. Structures were assigned to the three most abundant products of (perfluorohexyl)tetramethylcyclopentenol dehydration. Formal dehydration kinetics showed a second order reaction in benzene but zeroth order with induction period in chlorobenzene, suggesting mass transfer limitations in the more polar chlorobenzene. Some of the products were formed by consecutive isomerization of the others, as shown by the kinetic analysis. Full article

(This article belongs to the Special Issue Fluorine Chemistry 2016)

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1103 KiB

Open AccessArticle
Antioxidant and Cytotoxic Constituents from Wisteria sinensis
by Mona A. Mohamed, Manal M. Hamed, Allia M. Abdou, Wafaa S. Ahmed and Amal M. Saad

Molecules 2011, 16(5), 4020-4030; https://doi.org/10.3390/molecules16054020 - 17 May 2011
Cited by 14 | Viewed by 8669
Abstract
Chromatographic separation of an aqueous MeOH extract of Wisteria sinensis leaves has yielded six known flavonoids, two triterpene aglycones and the new acylated flavone glycoside chrysoeriol-7-O-[2''-O-(5'''-O-caffeoyl)-β-D-apiofuranosyl]-β-D-glucopyranoside (1). All metabolites were isolated [...] Read more.

Chromatographic separation of an aqueous MeOH extract of Wisteria sinensis leaves has yielded six known flavonoids, two triterpene aglycones and the new acylated flavone glycoside chrysoeriol-7-O-[2''-O-(5'''-O-caffeoyl)-β-D-apiofuranosyl]-β-D-glucopyranoside (1). All metabolites were isolated for the first time from the genus Wisteria. Their structures were established on the basis of their chromatographic properties, chemical and physicochemical methods including acid hydrolysis analysis, spectroscopic (UV, ¹H- and ¹³C-NMR) data and confirmed by ESI-MS analysis, as well as two-dimensional NMR (¹H-¹HCOSY, HMQC and HMBC). Biological studies of the defatted aqueous 80% methanol leaf extract and the major isolates 1, 6 and 7 were undertaken and they are reported herein for the first time to have significant cytotoxic activity against the Hep-G2 tumor cell line in addition to antioxidant activity. Full article

(This article belongs to the Section Medicinal Chemistry)

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329 KiB

Open AccessArticle
Apigenin Isolated from the Medicinal Plant Elsholtzia rugulosa Prevents β-Amyloid 25–35-Induces Toxicity in Rat Cerebral Microvascular Endothelial Cells
by Le Zhao, Lin Hou, Huijun Sun, Xin Yan, Xifeng Sun, Jianguang Li, Yong Bian, Yu Chu and Qingshan Liu

Molecules 2011, 16(5), 4005-4019; https://doi.org/10.3390/molecules16054005 - 13 May 2011
Cited by 31 | Viewed by 8625
Abstract
Endothelial cells of cerebral capillaries forming the blood-brain barrier play an important role in the pathogenesis and therapy of Alzheimer’s disease. Amyloid-β peptides are key pathological elements in the development of this disease. Apigenin (4’,5,7-tetrahydroxyflavone) is a plant flavonoid and pharmacologically active agent [...] Read more.

Endothelial cells of cerebral capillaries forming the blood-brain barrier play an important role in the pathogenesis and therapy of Alzheimer’s disease. Amyloid-β peptides are key pathological elements in the development of this disease. Apigenin (4’,5,7-tetrahydroxyflavone) is a plant flavonoid and pharmacologically active agent that can be isolated from several plant species. In the present study, effects of apigenin obtained from the medicinal plant Elsholtzia rugulosa (Labiatae) on primary cultured rat cerebral microvascular endothelial cells (CMECs) mediated by amyloid-β peptide 25–35 (Aβ_25–35) were examined. Aβ_25–35 showed toxic effects on CMECs, involving reduction of cell viability, release of lactate dehydrogenase (LDH), increase of nuclear condensation, over-production of intracellular reactive oxygen species (ROS), decrease of superoxide dismutase (SOD) activity, and breakage of the barrier integrity and function. Based on this model, we demonstrated that apigenin from the medicinal plant Elsholtzia rugulosa protected cultured rat CMECs by increasing cell viability, reducing LDH release, relieving nuclear condensation, alleviating intracellular ROS generation, increasing SOD activity, and strengthening the barrier integrity through the preservation of transendothelial electrical resistance, permeability property and characteristic enzymatic activity after being exposed to Aβ_25–35. In conclusion, apigenin isolated from Elsholtzia rugulosa has the ability to protect rat CMECs against Aβ_25–35-induced toxicity. Full article

(This article belongs to the Section Natural Products Chemistry)

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186 KiB

Open AccessArticle
A New Pyranoxanthone from Calophyllum soulattri
by Siau Hui Mah, Gwendoline Cheng Lian Ee, Mawardi Rahmani, Yun Hin Taufiq-Yap, Mohd Aspollah Sukari and Soek Sin Teh

Molecules 2011, 16(5), 3999-4004; https://doi.org/10.3390/molecules16053999 - 12 May 2011
Cited by 12 | Viewed by 6195
Abstract
Our interest on xanthones from the Calophyllum genus has led us to a detailed study on the chemistry of the stem bark of Calophyllum soulattri. This gave one new pyranoxanthone, soulattrin (1), together with three other xanthones, caloxanthone B (2 [...] Read more.

Our interest on xanthones from the Calophyllum genus has led us to a detailed study on the chemistry of the stem bark of Calophyllum soulattri. This gave one new pyranoxanthone, soulattrin (1), together with three other xanthones, caloxanthone B (2), caloxanthone C (3), macluraxanthone (4), the triterpene friedelin (5) and the steroid stigmasterol (6). The identities of these compounds were established using analyses of 1D and 2D NMR data. Full article

(This article belongs to the Section Natural Products Chemistry)

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259 KiB

Open AccessArticle
Synthesis of a Novel Benzoyl Adenosine Analog Containing a 1, 4-Dioxane Sugar Analog and the Synthesis of a Corresponding Uracil Adenine Dinucleotide
by Qiang Yu and Per Carlsen

Molecules 2011, 16(5), 3985-3998; https://doi.org/10.3390/molecules16053985 - 12 May 2011
Cited by 2 | Viewed by 5564
Abstract
Adenosine analogs in which the sugar unit was replaced by a 1,4-dioxane sugar equivalent, were prepared by coupling the 1,4-dioxane sugar analog as its anomeric acetates, with N6-benzoyl protected adenine. The 1,4-dioxane system was obtained in an enantioselective synthesis from (R,R [...] Read more.

Adenosine analogs in which the sugar unit was replaced by a 1,4-dioxane sugar equivalent, were prepared by coupling the 1,4-dioxane sugar analog as its anomeric acetates, with N6-benzoyl protected adenine. The 1,4-dioxane system was obtained in an enantioselective synthesis from (R,R)-dimethyl tartrate. Using standard phosphorimidite methodology, the adenine analog was further reacted with a 1,4-dioxane uridine analog to give the corresponding, protected dinucleotide, set-up for further condensation into larger oligonucleotides. Full article

(This article belongs to the Section Medicinal Chemistry)

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887 KiB

Open AccessArticle
Consecutive Low Doses of Cyclosporine A Induce Pro-Inflammatory Cytokines and Accelerate Allograft Skin Rejection
by Roberto López-Flores, Rafael Bojalil, José C. Benítez, Yadira Ledesma-Soto, César A. Terrazas, Miriam Rodríguez-Sosa and Luis I. Terrazas

Molecules 2011, 16(5), 3969-3984; https://doi.org/10.3390/molecules16053969 - 11 May 2011
Cited by 12 | Viewed by 8984
Abstract
Cyclosporine A (CsA) is a fungus-derived molecule with potent immunosuppressive activity that has been largely used to downregulate cell-mediated immune responses during transplantation. However, previous data have indicated that CsA shows immunomodulatory activity that relays on the antigen concentration and the dose of [...] Read more.

Cyclosporine A (CsA) is a fungus-derived molecule with potent immunosuppressive activity that has been largely used to downregulate cell-mediated immune responses during transplantation. However, previous data have indicated that CsA shows immunomodulatory activity that relays on the antigen concentration and the dose of CsA used. To test the hypothesis that minimal doses of CsA may show different outcomes on grafts, we used an experimental model for skin transplants in mice. ICR outbred mice received skin allografts and were either treated daily with different doses of CsA or left untreated. Untreated mice showed allograft rejection within 14 days, with graft necrosis, infiltration of neutrophils and macrophages and displayed high percentages of CD8⁺ T cells in the spleens, which were associated with high serum levels of IL-12, IFN-g and TNF-α. As expected, mice treated with therapeutic doses of CsA (15 mg/kg) did not show allograft rejection within the follow-up period of 30 days and displayed the lowest levels of IL-12, IFN-g and TNF-α as well as a reduction in CD8⁺ lymphocytes. In contrast, mice treated with consecutive minimal doses of CsA (5 × 10⁻⁵⁵ mg/kg) displayed an acute graft rejection as early as one to five days after skin allograft; they also displayed necrosis and strong inflammatory infiltration that was associated with high levels of IL-12, IFN-g and TNF-α. Moreover, the CD4⁺ CD25^hiFoxP3⁺ subpopulation of cells in the spleens of these mice was significantly inhibited compared with animals that received the therapeutic treatment of CsA and those treated with placebo. Our data suggest that consecutive, minimal doses of CsA may affect Treg cells and may stimulate innate immunity. Full article

(This article belongs to the Collection Bioactive Compounds)

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472 KiB

Open AccessReview
Synthesis of Glycosides of Glucuronic, Galacturonic and Mannuronic Acids: An Overview
by Anne Wadouachi and José Kovensky

Molecules 2011, 16(5), 3933-3968; https://doi.org/10.3390/molecules16053933 - 10 May 2011
Cited by 44 | Viewed by 12477
Abstract
Uronic acids are carbohydrates present in relevant biologically active compounds. Most of the latter are glycosides or oligosaccharides linked by their anomeric carbon, so their synthesis requires glycoside-bond formation. The activation of this anomeric center remains difficult due to the presence of the [...] Read more.

Uronic acids are carbohydrates present in relevant biologically active compounds. Most of the latter are glycosides or oligosaccharides linked by their anomeric carbon, so their synthesis requires glycoside-bond formation. The activation of this anomeric center remains difficult due to the presence of the electron-withdrawing C-5 carboxylic group. Herein we present an overview of glucuronidation, mannuronidation and galacturonidation reactions, including syntheses of prodrugs, oligosaccharides and stereochemical aspects. Full article

(This article belongs to the Special Issue Glycosides)

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967 KiB

Open AccessArticle
Effects of Thai Medicinal Herb Extracts with Anti-Psoriatic Activity on the Expression on NF-κB Signaling Biomarkers in HaCaT Keratinocytes
by Chanachai Saelee, Visa Thongrakard and Tewin Tencomnao

Molecules 2011, 16(5), 3908-3932; https://doi.org/10.3390/molecules16053908 - 10 May 2011
Cited by 63 | Viewed by 10186
Abstract
Psoriasis is a chronic inflammatory skin disorder characterized by rapid proliferation of keratinocytes and incomplete keratinization. Discovery of safer and more effective anti-psoriatic drugs remains an area of active research at the present time. Using a HaCaT keratinocyte cell line as an in [...] Read more.

Psoriasis is a chronic inflammatory skin disorder characterized by rapid proliferation of keratinocytes and incomplete keratinization. Discovery of safer and more effective anti-psoriatic drugs remains an area of active research at the present time. Using a HaCaT keratinocyte cell line as an in vitro model, we had previously found that ethanolic extracts from three Thai medicinal herbs, namely Alpinia galanga, Curcuma longa and Annona squamosa, possessed anti-psoriatic activity. In the current study, we aimed at investigating if these Thai medicinal herb extracts played a molecular role in suppressing psoriasis via regulation of NF-κB signaling biomarkers. Using semi-quantitative RT-PCR and report gene assays, we analyzed the effects of these potential herbal extracts on 10 different genes of the NF-κB signaling network in HaCaT cells. In accordance with our hypothesis, we found that the extract derived from Alpinia galanga significantly increased the expression of TNFAIP3 and significantly reduced the expression of CSF-1 and NF-kB2. Curcuma longa extract significantly decreased the expression of CSF-1, IL-8, NF-kB2, NF-kB1 and RelA, while Annona squamosa extract significantly lowered the expression of CD40 and NF-kB1. Therefore, this in vitro study suggested that these herbal extracts capable of functioning against psoriasis, might exert their activity by controlling the expression of NF-κB signaling biomarkers. Full article

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330 KiB

Open AccessArticle
Astragaloside IV Improves Metabolic Syndrome and Endothelium Dysfunction in Fructose-Fed Rats
by Ning Zhang, Xu-Hui Wang, Shi-Long Mao and Feng Zhao

Molecules 2011, 16(5), 3896-3907; https://doi.org/10.3390/molecules16053896 - 10 May 2011
Cited by 51 | Viewed by 9175
Abstract
The prevalence of metabolic syndrome has increased in modern society and the condition is proving to be a common precursor of cardiovascular disease. The aim of the present study was to investigate whether astragaloside IV, a major active constituent of Astragalus membranaceus (Fisch) [...] Read more.

The prevalence of metabolic syndrome has increased in modern society and the condition is proving to be a common precursor of cardiovascular disease. The aim of the present study was to investigate whether astragaloside IV, a major active constituent of Astragalus membranaceus (Fisch) Bge., is able to prevent the development of hypertension and endothelial dysfunction in fructose-fed rats. Rats were fed with 10% fructose in their drinking water for 8 weeks. From the beginning of week 5, two groups of fructose-fed rats were treated with 0.5 or 2 mg/kg, i.p., astragaloside IV. Another group of fructose-fed rats, injected with the same volume of vehicle (dimethylsulfoxide, DMSO) from week 5, served as the control group. At the end of the treatment period, blood pressure, blood glucose, glucose tolerance, blood insulin and lipids were determined. In addition, in vitro experiments were conducted at the end of the eight week treatment period to evaluate endothelium-dependent aortic vasorelaxation, as well as myocardial and aortic tissue levels of nitrate and nitrite (NOx) and cGMP. Fructose-fed rats developed clustering signs of metabolic syndrome, such as increased bodyweight, mild hypertension, hyperinsulinaemia, hypertriglyceridaemia, impaired glucose tolerance and impaired endothelium-dependent vasorelaxation. Administration of astragaloside IV reduced blood pressure and triglyceride levels in fructose-fed rats and high dose of astragaloside IV also improved glucose tolerance and endothelium-dependent vasorelaxation. The astragaloside IV-induced improvement in vasorelaxation was associated with increased levels of aortic NOx and cGMP and was abrogated by blockade of nitric oxide synthase with NG-nitro-l-arginine methyl ester (l-NAME). On the basis of its favourable effects on lipid metabolism, endothelium-dependent vasorelaxation and the nitric oxide–cGMP-related pathway, astragaloside IV may be useful in ameliorating food-induced metabolic syndrome. Full article

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273 KiB

Open AccessArticle
Fungitoxicity against Botrytis cinerea of a Flavonoid Isolated from Pseudognaphalium robustum
by Milena Cotoras, Leonora Mendoza, Alexis Muñoz, Karen Yáñez, Paulo Castro and María Aguirre

Molecules 2011, 16(5), 3885-3895; https://doi.org/10.3390/molecules16053885 - 9 May 2011
Cited by 23 | Viewed by 7068
Abstract
The fungotoxicity against Botrytis cinerea of a flavonoid isolated from Pseudognaphalium robustum was analyzed. Two absorption column chromatographies and one semipreparative thin layer chromatography were used to purify the active flavonoid. It was determined, by ¹H-NMR spectroscopy and co-elution with standards in [...] Read more.

The fungotoxicity against Botrytis cinerea of a flavonoid isolated from Pseudognaphalium robustum was analyzed. Two absorption column chromatographies and one semipreparative thin layer chromatography were used to purify the active flavonoid. It was determined, by ¹H-NMR spectroscopy and co-elution with standards in HPLC, that this compound was 5,7-dihydroxy-3,8-dimethoxyflavone (gnaphaliin A). To determine the fungitoxicity of the purified compound, the effect on in vitro mycelial growth and conidial germination was studied. The compound concentration that reduced mycelial growth by 50% was 45.5 mg/mL. This compound also partially affected conidial germination of B. cinerea, reduced oxygen consumption by germinating conidia and affected the integrity of plasma membrane. Finally, using cyclic voltammetry, it was shown that the purified flavone had a pro-oxidant effect. Full article

(This article belongs to the Section Natural Products Chemistry)

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