Molecules

123 KiB

Open AccessArticle

Chemical Composition and Toxicity against Sitophilus zeamais and Tribolium castaneum of the Essential Oil of Murraya exotica Aerial Parts

by Wei Qing Li, Cai Hong Jiang, Sha Sha Chu, Ming Xue Zuo and Zhi Long Liu

Molecules 2010, 15(8), 5831-5839; https://doi.org/10.3390/molecules15085831 - 25 Aug 2010

Cited by 90 | Viewed by 12833

Abstract

In our screening program for new agrochemicals from Chinese medicinal herbs, Murraya exotica was found to possess insecticidal activity against the maize weevil, Sitophilus zeamais and red flour beetle, Tribolium castaneum. The essential oil of aerial parts of M. exotica was obtained [...] Read more.

In our screening program for new agrochemicals from Chinese medicinal herbs, Murraya exotica was found to possess insecticidal activity against the maize weevil, Sitophilus zeamais and red flour beetle, Tribolium castaneum. The essential oil of aerial parts of M. exotica was obtained by hydrodistillation and investigated by GC and GC-MS. The main components of M. exotica essential oil were spathulenol (17.7%), a-pinene (13.3%), caryophyllene oxide (8.6%), and a-caryophyllene (7.3%). Essential oil of M. exotica possessed fumigant toxicity against S. zeamais and T. castaneum adults with LC₅₀ values of 8.29 and 6.84 mg/L, respectively. The essential oils also show contact toxicity against S. zeamais and T. castaneum adults with LD₅₀ values of 11.41 and 20.94 mg/adult, respectively. Full article

247 KiB

Open AccessArticle

High Molecular Weight Glucan of the Culinary Medicinal Mushroom Agaricus bisporus is an α-Glucan that Forms Complexes with Low Molecular Weight Galactan

by Fhernanda R. Smiderle, Guilherme L. Sassaki, Jeroen van Arkel, Marcello Iacomini, Harry J. Wichers and Leo J.L.D. Van Griensven

Molecules 2010, 15(8), 5818-5830; https://doi.org/10.3390/molecules15085818 - 25 Aug 2010

Cited by 37 | Viewed by 14317

Abstract

An a-glucan was isolated from the culinary medicinal mushroom A. bisporus by hot water extraction, ethanol precipitation and DEAE-cellulose chromatography. The resulting material showed a single HMW peak excluded from a Sephadex G50 column that could completely be degraded by α-amylase treatment. After [...] Read more.

An a-glucan was isolated from the culinary medicinal mushroom A. bisporus by hot water extraction, ethanol precipitation and DEAE-cellulose chromatography. The resulting material showed a single HMW peak excluded from a Sephadex G50 column that could completely be degraded by α-amylase treatment. After heating in 1% SDS a small additional peak of low MW eluted from the G50 column. The monosaccharide composition of the main peak was evaluated by HPLC, and was found to consist of a majority of glucose (97.6%), and a minor proportion of galactose (2.4%). Methylation analysis and degradation by a-amylase indicated the presence of an a-glucan with a main chain consisting of (1®4)-linked units, substituted at O-6 by α-D-glucopyranose single-units in the relation 1:8. Mono- (¹³C-, ¹H-NMR) and bidimensional [¹H (obs.),¹³C-HSQC] spectroscopy analysis confirmed the a-configuration of the Glcp residues by low frequency resonances of C-1 at d 100.6, 100.2, and 98.8 ppm and H-1 high field ones at d 5.06, 5.11, and 4.74 ppm. The DEPT-¹³C-NMR allowed assigning the non-substituted and O-substituted –CH₂ signals at d 60.3/60.8 and 66.2 ppm, respectively. Other assignments were attributed to C-2, C-3, C-4, C-5 and C-6 of the non-reducing ends at d 71.8; 72.8; 70.0; 71.3 and 60.3/60.8 ppm, respectively. The minor proportion of galactose that was demonstrated was probably derived from a complex between the a-glucan and a low molecular weight galactan. Full article

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216 KiB

Open AccessArticle

Antimicrobial and Antioxidant Activities of the Root Bark Essential Oil of Periploca sepium and Its Main Component 2-Hydroxy-4-methoxybenzaldehyde

by Jihua Wang, Hao Liu, Jianglin Zhao, Haifeng Gao, Ligang Zhou, Zhilong Liu, Yuanquan Chen and Peng Sui

Molecules 2010, 15(8), 5807-5817; https://doi.org/10.3390/molecules15085807 - 24 Aug 2010

Cited by 112 | Viewed by 15667

Abstract

The root bark essential oil of Periploca sepium Bunge (Asclepiadaceae/ Apocynaceae) obtained by hydrodistillation was investigated by GC and GC-MS. 2-Hydroxy-4-methoxybenzaldehyde was found to be the main component (78.8% of the total) among 17 identified compounds. 2-Hydroxy-4-methoxybenzaldehyde was separated and purified by preparative [...] Read more.

The root bark essential oil of Periploca sepium Bunge (Asclepiadaceae/ Apocynaceae) obtained by hydrodistillation was investigated by GC and GC-MS. 2-Hydroxy-4-methoxybenzaldehyde was found to be the main component (78.8% of the total) among 17 identified compounds. 2-Hydroxy-4-methoxybenzaldehyde was separated and purified by preparative thin layer chromatography, and was further identified by means of physicochemical and spectrometric analysis. Both the essential oil and 2-hydroxy-4-methoxybenzaldehyde exhibited antimicrobial activities on all test bacteria and fungi, with MBC/MFC values ranging from 125 μg/mL to 300 μg/mL, MIC values from 80 μg/mL to 300 μg/mL, and IC₅₀ values from 63.29 μg/mL to 167.30 μg/mL. They also showed moderate antioxidant activity in the DPPH free radical scavenging, β-carotene bleaching and ferrozine-ferrous ions assays. The results indicated that the major portion of these antimicrobial and antioxidant activities was due to the presence of 2-hydroxy-4-methoxy-benzaldehyde in the oil, which could potentially be developed as an antimicrobial and antioxidant agent in the future. Full article

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

156 KiB

Open AccessArticle

Yields and Constituents of Essential Oil from Cones of Pinaceae spp. Natively Grown in Turkey

by Ibrahim Tumen, Harzemsah Hafizoglu, Ayben Kilic, Ilhami Emrah Dönmez, Huseyin Sivrikaya and Markku Reunanen

Molecules 2010, 15(8), 5797-5806; https://doi.org/10.3390/molecules15085797 - 24 Aug 2010

Cited by 77 | Viewed by 9336

Abstract

In this study, the yields and composition of essential oils obtained from the cones of Pinaceae family species natively grown in Turkey were investigated. Essential oils were obtained by hydrodistillation. Oil yields were 0.13-0.48 mL/100 g in pine cones, 0.42-0.59 mL/100g in fir, [...] Read more.

In this study, the yields and composition of essential oils obtained from the cones of Pinaceae family species natively grown in Turkey were investigated. Essential oils were obtained by hydrodistillation. Oil yields were 0.13-0.48 mL/100 g in pine cones, 0.42-0.59 mL/100g in fir, 0.36 mL/100g in spruce and 0.37 mL/100g in cedar. While a-pinene (47.1-14.8%) was the main constituent of P. slyvestris, P. nigra and P. halepensis, limonene (62.8%) in P. pinea and b-pinene (39.6%) in P. brutia were found in higher amounts. Like in P. pinea, limonene was the main compound in Cedrus libani (22.7%). In fir species the major compounds were a-pinene (70.6-53.0%) and b-pinene (10.9-8.2%). Contrary to other species b-pinene (32.7%) was found as a major compound in Picea orientalis. Full article

(This article belongs to the Section Natural Products Chemistry)

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267 KiB

Open AccessArticle

Asymmetric Synthesis of α-Aminophosphonates Using the Inexpensive Chiral Catalyst 1,1’-Binaphthol Phosphate

by Weiming Xu, Sha Zhang, Song Yang, Lin-Hong Jin, Pinaki S. Bhadury, De-Yu Hu and Yuping Zhang

Molecules 2010, 15(8), 5782-5796; https://doi.org/10.3390/molecules15085782 - 24 Aug 2010

Cited by 24 | Viewed by 11239

Abstract

Asymmetric addition under mild conditions of dialkyl phosphites on aldimines derived from cinnamaldehyde catalyzed by the inexpensive chiral organocatalyst (R)-3,3’-[4-fluorophenyl]₂-1,1’-binaphthol phosphate has been found effective to give new α-amino-phosphonates 9 in moderate yields (30–65%) and enantiomeric excess (8.4%–61.9%). Full article

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156 KiB

Open AccessReview

Click Reactions and Boronic Acids: Applications, Issues, and Potential Solutions

by Chaofeng Dai, Yunfeng Cheng, Jianmei Cui and Binghe Wang

Molecules 2010, 15(8), 5768-5781; https://doi.org/10.3390/molecules15085768 - 23 Aug 2010

Cited by 36 | Viewed by 11198

Abstract

Boronic acids have been widely used in a wide range of organic reactions, in the preparation of sensors for carbohydrates, and as potential pharmaceutical agents. With the growing importance of click reactions, inevitably they are also applied to the synthesis of compounds containing [...] Read more.

Boronic acids have been widely used in a wide range of organic reactions, in the preparation of sensors for carbohydrates, and as potential pharmaceutical agents. With the growing importance of click reactions, inevitably they are also applied to the synthesis of compounds containing the boronic acid moiety. However, such applications have unique problems. Chief among them is the issue of copper-mediated boronic acid degradation in copper-assisted [2,3]-cycloadditions involving an alkyne and an azido compound as the starting materials. This review summarizes recent developments, analyzes potential issues, and discusses known as well as possible solutions. Full article

(This article belongs to the Special Issue Click Chemistry)

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289 KiB

Open AccessArticle

Organic-Inorganic Hybrid Silica Material Derived from a Monosilylated Grubbs-Hoveyda Ruthenium Carbene as a Recyclable Metathesis Catalyst

by Guadalupe Borja, Roser Pleixats, Ramón Alibés, Xavier Cattoën and Michel Wong Chi Man

Molecules 2010, 15(8), 5756-5767; https://doi.org/10.3390/molecules15085756 - 23 Aug 2010

Cited by 13 | Viewed by 9982

Abstract

The synthesis of a monosilylated Grubbs-Hoveyda ruthenium alkylidene complex is described, as well as the preparation and characterization of the corresponding material by sol-gel cogelification with tetraethoxysilane (TEOS) and the assay of this recyclable supported catalyst in ring-closing diene and enyne metathesis reactions [...] Read more.

The synthesis of a monosilylated Grubbs-Hoveyda ruthenium alkylidene complex is described, as well as the preparation and characterization of the corresponding material by sol-gel cogelification with tetraethoxysilane (TEOS) and the assay of this recyclable supported catalyst in ring-closing diene and enyne metathesis reactions under thermal and microwave conditions. Full article

(This article belongs to the Special Issue Ring-Closing Metathesis)

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309 KiB

Open AccessArticle

Development of a Sphingosylphosphorylcholine Detection System Using RNA Aptamers

by Katsunori Horii, Kazuya Omi, Yoshihito Yoshida, Yuka Imai, Nobuya Sakai, Asako Oka, Hiromi Masuda, Makio Furuichi, Tetsuji Tanimoto and Iwao Waga

Molecules 2010, 15(8), 5742-5755; https://doi.org/10.3390/molecules15085742 - 20 Aug 2010

Cited by 15 | Viewed by 9435

Abstract

Sphingosylphosphorylcholine (SPC) is a lysosphingolipid that exerts multiple functions, including acting as a spasmogen, as a mitogenic factor for various types of cells, and sometimes as an inflammatory mediator. Currently, liquid chromatography/tandem mass spectrometry (LC/MS/MS) is used for the quantitation of SPC. However, [...] Read more.

Sphingosylphosphorylcholine (SPC) is a lysosphingolipid that exerts multiple functions, including acting as a spasmogen, as a mitogenic factor for various types of cells, and sometimes as an inflammatory mediator. Currently, liquid chromatography/tandem mass spectrometry (LC/MS/MS) is used for the quantitation of SPC. However, because of the complicated procedures required it may not be cost effective, hampering its regular usage in a routine practical SPC monitoring. In this report, we have generated RNA aptamers that bind to SPC with high affinity using an in vitro selection procedure and developed an enzyme-linked aptamer assay system using the minimized SPC aptamer that can successfully distinguish SPC from the structurally related sphingosine 1-phosphate (S1P). This is the first case of the Systematic Evolution of Ligands by EXponential enrichment (SELEX) process being performed with a lysosphingolipid. The SPC aptamers would be valuable tools for the development of aptamer-based medical diagnosis and for elucidating the biological role of SPC. Full article

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165 KiB

Open AccessArticle

Chemical Composition and Larvicidal Activity against Aedes aegypti Larvae of Essential Oils from Four Guarea Species

by Lyege Amazonas Maciel Magalhães, Maria Da Paz Lima, Marcia Ortiz Mayo Marques, Roselaine Facanali, Ana Cristina da Silva Pinto and Wanderli Pedro Tadei

Molecules 2010, 15(8), 5734-5741; https://doi.org/10.3390/molecules15085734 - 19 Aug 2010

Cited by 71 | Viewed by 12920

Abstract

The essential oils of four Guarea species collected at Manaus (Amazonas, Brazil) were obtained by hydrodistillation and analyzed by GC-MS. Except for one diterpene detected, the compounds identified in the essential oils were hydrocarbons and oxygenated sesquiterpenes. The major sesquiterpenes were α-santalene (26.26%) [...] Read more.

The essential oils of four Guarea species collected at Manaus (Amazonas, Brazil) were obtained by hydrodistillation and analyzed by GC-MS. Except for one diterpene detected, the compounds identified in the essential oils were hydrocarbons and oxygenated sesquiterpenes. The major sesquiterpenes were α-santalene (26.26%) and α-copaene (14.61%) from G. convergens branches; caryophyllene epoxide (40.91%) and humulene epoxide II (14.43%) from G. humaitensis branches; cis-caryophyllene (33.37%) and α-trans-bergamotene (11.88%) from G. scabra leaves; caryophyllene epoxide (36.54%) in leaves and spathulenol (14.34%) in branches from G. silvatica. The diterpene kaurene (15.61%) was found in G. silvatica leaves. Larvicidal activity assay of essential oils against third-instar Aedes aegypti larvae revealed that at higher concentrations (500 and 250 μg/mL), all the essential oils caused 100% mortality after 24 h of exposure. The most active essential oils were those of G. humaitensis branches (LC₅₀ 48.6 μg/mL), G. scabra leaves (LC₅₀ 98.6 μg/mL) and G. silvatica (LC₅₀ 117.9 μg/mL). The differences in the toxicity of essential oils of Guarea species on A. aegypti are due to qualitative and quantitative variations of the components, therefore the larvicidal effect may be due to higher amount of the sesquiterpenes with caryophyllane skeleton. Full article

(This article belongs to the Special Issue Phytochemicals with Signaling, Medicinal and Therapeutic Properties)

331 KiB

Open AccessArticle

Design, Synthesis, and Biological Evaluation of Benzylamino-Methanone Based Cholesteryl Ester Transfer Protein Inhibitors

by Ghassan Abu Sheikha, Reema Abu Khalaf, Areej Melhem and Ghadeer Albadawi

Molecules 2010, 15(8), 5721-5733; https://doi.org/10.3390/molecules15085721 - 19 Aug 2010

Cited by 23 | Viewed by 9869

Abstract

Cholesteryl ester transfer protein (CETP) is a glycoprotein involved in transporting lipoprotein particles and neutral lipids between high-density lipoprotein (HDL) and low density lipoproteins (LDL) and therefore its a proper target for treating dyslipidemia and related disorders. Guided by our previosuly-reported pharmacophore and [...] Read more.

Cholesteryl ester transfer protein (CETP) is a glycoprotein involved in transporting lipoprotein particles and neutral lipids between high-density lipoprotein (HDL) and low density lipoproteins (LDL) and therefore its a proper target for treating dyslipidemia and related disorders. Guided by our previosuly-reported pharmacophore and QSAR models for CETP inhibition, we synthesized and bioassayed a series of benzylamino-methanones. The most potent illustrated 30% CETP inhibition at 10 μM. Full article

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493 KiB

Open AccessArticle

Synthesis and Application of a 2-[(4-Fluorophenyl)-sulfonyl]ethoxy Carbonyl(Fsec) Protected Glycosyl Donor in Carbohydrate Chemistry

by Sara Spjut, Weixing Qian and Mikael Elofsson

Molecules 2010, 15(8), 5708-5720; https://doi.org/10.3390/molecules15085708 - 19 Aug 2010

Cited by 1 | Viewed by 9636

Abstract

The 2-[(4-fluorophenyl)sulfonyl]ethoxy carbonyl (Fsec) group for protection of hydroxyl groups has been designed, synthesized, and evaluated. Fsec-Cl was readily prepared in 91% yield over three steps and subsequently used to protect 4-fluorobenzyl alcohol in high yield. The Fsec group was cleaved from the [...] Read more.

The 2-[(4-fluorophenyl)sulfonyl]ethoxy carbonyl (Fsec) group for protection of hydroxyl groups has been designed, synthesized, and evaluated. Fsec-Cl was readily prepared in 91% yield over three steps and subsequently used to protect 4-fluorobenzyl alcohol in high yield. The Fsec group was cleaved from the resulting model compound under mild basic conditions e.g., 20% piperidine in DMF and was stable under acidic conditions, e.g., neat acetic acid. The Fsec group was used to protect the unreactive 4-OH in a galactose building block that was later used in the synthesis of 6-aminohexyl galabioside. Full article

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

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253 KiB

Open AccessArticle

Solid-Phase Synthesis of Oligodeoxynucleotides Containing N⁴-[2-(t-butyldisulfanyl)ethyl]-5-methylcytosine Moieties

by Sónia Pérez-Rentero, Alejandra V. Garibotti and Ramón Eritja

Molecules 2010, 15(8), 5692-5707; https://doi.org/10.3390/molecules15085692 - 18 Aug 2010

Cited by 8 | Viewed by 8314

Abstract

An efficient route for the synthesis of the phosphoramidite derivative of 5-methylcytosine bearing a tert-butylsulfanyl group protected thiol is described. This building block is used for the preparation of oligonucleotides carrying a thiol group at the nucleobase at the internal position of [...] Read more.

An efficient route for the synthesis of the phosphoramidite derivative of 5-methylcytosine bearing a tert-butylsulfanyl group protected thiol is described. This building block is used for the preparation of oligonucleotides carrying a thiol group at the nucleobase at the internal position of a DNA sequence. The resulting thiolated oligonucleotides are useful intermediates to generate oligonucleotide conjugates carrying molecules of interest at internal positions of a DNA sequence. Full article

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

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369 KiB

Open AccessArticle

A Facile Synthesis of 3-Substituted 9H-Pyrido[3,4-b]indol-1(2H)-one Derivatives from 3-Substituted β-Carbolines

by Guowu Lin, Yue Wang, Qingfa Zhou, Weifang Tang, Jian Wang and Tao Lu

Molecules 2010, 15(8), 5680-5691; https://doi.org/10.3390/molecules15085680 - 17 Aug 2010

Cited by 21 | Viewed by 10560

Abstract

A mild and efficient two-step synthesis of 3-substituted β-carbolinone derivatives from 3-substituted β-carboline in good yields is described. A possible reaction mechanism for the formation of the skeleton of β-carbolin-1-one is proposed. The structures of these compounds were established by IR, ¹H-NMR, [...] Read more.

A mild and efficient two-step synthesis of 3-substituted β-carbolinone derivatives from 3-substituted β-carboline in good yields is described. A possible reaction mechanism for the formation of the skeleton of β-carbolin-1-one is proposed. The structures of these compounds were established by IR, ¹H-NMR, ¹³C-NMR, mass spectrometry and elemental analysis, as well as X-ray crystallographic analysis of 4-2 and 6-2. Full article

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348 KiB

Open AccessCommunication

Synthesis, Identification and Anti-Cancer Activity of 1-(4-Methylpent-2-enyl)-2-(4-phenylbut-2-enyl)disulfane

by Chunxiao Ji, Fenglian Ren and Ming Xu

Molecules 2010, 15(8), 5671-5679; https://doi.org/10.3390/molecules15085671 - 16 Aug 2010

Cited by 1 | Viewed by 6167

Abstract

In this study, we synthesized 1-(4-methylpent-2-enyl)-2-(4-phenylbut-2- enyl)disulfane using sodium sulfide, 1-bromine-4-methyl-2-amylene and 1-(4-bromine-2- butylene)benzene as raw materials. The yield rate of target product was 84%. The structure of the target product was confirmed by GC-MS, ¹H-NMR and elemental analysis. The results of [...] Read more.

In this study, we synthesized 1-(4-methylpent-2-enyl)-2-(4-phenylbut-2- enyl)disulfane using sodium sulfide, 1-bromine-4-methyl-2-amylene and 1-(4-bromine-2- butylene)benzene as raw materials. The yield rate of target product was 84%. The structure of the target product was confirmed by GC-MS, ¹H-NMR and elemental analysis. The results of anti-cancer activity experiments showed that 1-(4-methylpent-2-enyl)-2-(4- phenylbut-2-enyl)disul-fane could significantly inhibit the proliferation, induce the apoptosis of CNE2 cells in a dose dependent manner, and could significantly enhance the activity of XIAP. Full article

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360 KiB

Open AccessArticle

Antioxidant Tannins from Stem Bark and Fine Root of Casuarina equisetifolia

by Shang-Ju Zhang, Yi-Ming Lin, Hai-Chao Zhou, Shu-Dong Wei, Guang-Hui Lin and Gong-Fu Ye

Molecules 2010, 15(8), 5658-5670; https://doi.org/10.3390/molecules15085658 - 16 Aug 2010

Cited by 27 | Viewed by 11945

Abstract

Structures of condensed tannins from the stem bark and fine root of Casuarina equisetifolia were identified using MALDI-TOF MS and HPLC analyses. The condensed tannins from stem bark and fine root consist predominantly of procyanidin combined with prodelphinidin and propelargonidin, and epicatechin is [...] Read more.

Structures of condensed tannins from the stem bark and fine root of Casuarina equisetifolia were identified using MALDI-TOF MS and HPLC analyses. The condensed tannins from stem bark and fine root consist predominantly of procyanidin combined with prodelphinidin and propelargonidin, and epicatechin is the main extension unit. The condensed tannins had different polymer chain lengths, varying from trimers to tridecamer for stem bark and to pentadecamer for fine root. The antioxidant activities were measured by two models: 1,1-diphenyl-2- picrylhydrazyl (DPPH) radical scavenging activity and ferric reducing/ antioxidant power (FRAP). The condensed tannins extracted from C. equisetifolia showed very good DPPH radical scavenging activity and ferric reducing/ antioxidant power, suggesting that these extracts may be considered as new sources of natural antioxidants for food and nutraceutical products. Full article

(This article belongs to the Special Issue Tannins)

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306 KiB

Open AccessArticle

Study of Cyclic Quaternary Ammonium Bromides by B3LYP Calculations, NMR and FTIR Spectroscopies

by Bogumił Brycki, Adrianna Szulc and Iwona Kowalczyk

Molecules 2010, 15(8), 5644-5657; https://doi.org/10.3390/molecules15085644 - 16 Aug 2010

Cited by 14 | Viewed by 8024

Abstract

N,N-dioctyl-azepanium, -piperidinium and -pyrrolidinium bromides 1-3, have been obtained and characterized by FTIR and NMR spectroscopy. DFT calculations have also been carried out. The optimized bond lengths, bond angles and torsion angles calculated by B3LYP/6-31G(d,p) approach have been presented. [...] Read more.

N,N-dioctyl-azepanium, -piperidinium and -pyrrolidinium bromides 1-3, have been obtained and characterized by FTIR and NMR spectroscopy. DFT calculations have also been carried out. The optimized bond lengths, bond angles and torsion angles calculated by B3LYP/6-31G(d,p) approach have been presented. Both FTIR and Raman spectra of 1-3 are consistent with the calculated structures in the gas phase. The screening constants for ¹³C and ¹H atoms have been calculated by the GIAO/B3LYP/6-31G(d,p) approach and analyzed. Linear correlations between the experimental ¹H and ¹³C chemical shifts and the computed screening constants confirm the optimized geometry. Full article

(This article belongs to the Section Organic Chemistry)

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169 KiB

Open AccessArticle

Synthesis and Biological Evaluation of 2,5-Bis(alkylamino)-1,4-benzoquinones

by Luiz Cláudio Almeida Barbosa, Ulisses Alves Pereira, Célia Regina Alvares Maltha, Róbson Ricardo Teixeira, Vânia Maria Moreira Valente, José Roberto Oliveira Ferreira, Letícia Veras Costa-Lotufo, Manoel Odorico Moraes and Cláudia Pessoa

Molecules 2010, 15(8), 5629-5643; https://doi.org/10.3390/molecules15085629 - 13 Aug 2010

Cited by 30 | Viewed by 10342

Abstract

A series of twelve 2,5-bis(alkylamino)-1,4-benzoquinones were prepared in yields ranging from 9–58% via the reaction between p-benzoquinone and various amines. The structures of the synthesized compounds were confirmed by IR, ¹H- and ¹³C-NMR and MS analyses. The phytotoxicity of the [...] Read more.

A series of twelve 2,5-bis(alkylamino)-1,4-benzoquinones were prepared in yields ranging from 9–58% via the reaction between p-benzoquinone and various amines. The structures of the synthesized compounds were confirmed by IR, ¹H- and ¹³C-NMR and MS analyses. The phytotoxicity of the 2,5-bis(alkylamino)-1,4-benzoquinones was evaluated against two crop species, Cucumis sativus and Sorgum bicolor, at 1.0 × 10^-3 mol/L. In general, the quinones displayed inhibitory effects on the dicotyledonous species C. sativus (7–74%). On the other hand stimulatory effects were observed on S. bicolor (monocotyledonous). Similar results were observed in the biological assays carried out with the weed species Ipomoea grandifolia (dicotyledonous) and Brachiaria decumbens (monocotyledonous). In addition, the cytotoxicity of the 2,5-bis(alkylamino)-1,4-benzoquinones was assayed against HL-60 (leukemia), MDA-MB-435 (melanoma), SF-295 (brain) and HCT-8 (colon) human cancer cell lines and human peripheral blood mononuclear cells (PBMC), as representatives of healthy cells, using a MTT and an Alamar Blue assay. Compound 12 was the most active, displaying cytotoxicity against all cancer cell lines tested. Full article

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334 KiB

Open AccessArticle

Synthesis and Characterization of Azo Compounds and Study of the Effect of Substituents on Their Liquid Crystalline Behavior

by Uhood J. Al-Hamdani, Tarik E. Gassim and Howraa H. Radhy

Molecules 2010, 15(8), 5620-5628; https://doi.org/10.3390/molecules15085620 - 13 Aug 2010

Cited by 48 | Viewed by 8090

Abstract

In this paper we present six select mesomorphic azo compounds distinguished by the presence of diverse substituents on a central benzene nucleus. All the synthesized compounds exhibit enantiotropic mesophases. The mesomorphic properties of the substituted compounds were compared with those of the unsubstituted [...] Read more.

In this paper we present six select mesomorphic azo compounds distinguished by the presence of diverse substituents on a central benzene nucleus. All the synthesized compounds exhibit enantiotropic mesophases. The mesomorphic properties of the substituted compounds were compared with those of the unsubstituted parent compound to evaluate the effect of the nature and position of the substituents on mesomorphism. Full article

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194 KiB

Open AccessArticle

Enantioselctive Syntheses of Sulfur Analogues of Flavan-3-Ols

by Pradeep K. Sharma, Min He, Jurjus Jurayj, Da-Ming Gou, Richard Lombardy, Leo J. Romanczy, Jr. and Hagen Schroeter

Molecules 2010, 15(8), 5595-5619; https://doi.org/10.3390/molecules15085595 - 13 Aug 2010

Cited by 21 | Viewed by 12327

Abstract

The first enantioselective syntheses of sulfur flavan-3-ol analogues 1–8 have been accomplished, whereby the oxygen atom of the pyran ring has been replaced by a sulfur atom. The key steps were: (a) Pd(0) catalyzed introduction of –St-butyl group, (b) [...] Read more.

The first enantioselective syntheses of sulfur flavan-3-ol analogues 1–8 have been accomplished, whereby the oxygen atom of the pyran ring has been replaced by a sulfur atom. The key steps were: (a) Pd(0) catalyzed introduction of –St-butyl group, (b) Sharpless enantioselective dihydroxylation of the alkene, (c) acid catalyzed ring closure to produce the thiopyran ring, and (d) removal of benzyl groups using N,N-dimethylaniline and AlCl₃. The compounds were isolated in high chemical and optical purity. Full article

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

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166 KiB

Open AccessReview

Emerging Biological Importance of Central Nervous System Lanthionines

by Kenneth Hensley, Kalina Venkova and Alexandar Christov

Molecules 2010, 15(8), 5581-5594; https://doi.org/10.3390/molecules15085581 - 13 Aug 2010

Cited by 61 | Viewed by 12528

Abstract

Lanthionine (Lan), the thioether analog of cystine, is a natural but nonproteogenic amino acid thought to form naturally in mammals through promiscuous reactivity of the transsulfuration enzyme cystathionine-b-synthase (CbS). Lanthionine exists at appreciable concentrations in mammalian brain, where it undergoes aminotransferase conversion to [...] Read more.

Lanthionine (Lan), the thioether analog of cystine, is a natural but nonproteogenic amino acid thought to form naturally in mammals through promiscuous reactivity of the transsulfuration enzyme cystathionine-b-synthase (CbS). Lanthionine exists at appreciable concentrations in mammalian brain, where it undergoes aminotransferase conversion to yield an unusual cyclic thioether, lanthionine ketimine (LK; 2H-1,4-thiazine-5,6-dihydro-3,5-dicarboxylic acid). Recently, LK was discovered to possess neuroprotective, neuritigenic and anti-inflammatory activities. Moreover, both LK and the ubiquitous redox regulator glutathione (g-glutamyl-cysteine-glycine) bind to mammalian lanthionine synthetase-like protein-1 (LanCL1) protein which, along with its homolog LanCL2, has been associated with important physiological processes including signal transduction and insulin sensitization. These findings begin to suggest that Lan and its downstream metabolites may be physiologically important substances rather than mere metabolic waste. This review summarizes the current state of knowledge about lanthionyl metabolites with emphasis on their possible relationships to LanCL1/2 proteins and glutathione. The potential significance of lanthionines in paracrine signaling is discussed with reference to opportunities for utilizing bioavailable pro-drug derivatives of these compounds as novel pharmacophores. Full article

(This article belongs to the Special Issue Neuroactive Compounds)

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Open AccessArticle

A Simple, Safe and Efficient Synthesis of Tyrian Purple (6,6′-Dibromoindigo)

by Joel L. Wolk and Aryeh A. Frimer

Molecules 2010, 15(8), 5561-5580; https://doi.org/10.3390/molecules15085561 - 12 Aug 2010

Cited by 16 | Viewed by 17209

Abstract

6,6’-Dibromoindigo is a major component of the historic pigment Tyrian purple, arguably the most famous dye of antiquity. Over the last century, chemists have been interested in developing practical syntheses of the compound We describe herein a new, reasonably simple and efficient synthesis [...] Read more.

6,6’-Dibromoindigo is a major component of the historic pigment Tyrian purple, arguably the most famous dye of antiquity. Over the last century, chemists have been interested in developing practical syntheses of the compound We describe herein a new, reasonably simple and efficient synthesis of Tyrian purple which opens the way to the production of large quantities of the dye with minimal hazards and at low cost. Full article

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Open AccessArticle

Chemical Constituents with Free-Radical-Scavenging Activities from the Stem of Microcos paniculata

by Hua Fan, Guang-Zhong Yang, Tong Zheng, Zhi-Nan Mei, Xiang-Ming Liu, Yu Chen and Su Chen

Molecules 2010, 15(8), 5547-5560; https://doi.org/10.3390/molecules15085547 - 12 Aug 2010

Cited by 26 | Viewed by 11769

Abstract

The free-radical-scavenging activities of various solvent extracts of Microcos paniculata were evaluated through in vitro model systems, such as 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) and Co (II) EDTA-induced luminol chemiluminescence by flow injection. In all three of these systems the ethyl acetate (EtOAc) extract [...] Read more.

The free-radical-scavenging activities of various solvent extracts of Microcos paniculata were evaluated through in vitro model systems, such as 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) and Co (II) EDTA-induced luminol chemiluminescence by flow injection. In all three of these systems the ethyl acetate (EtOAc) extract showed the highest free-radical-scavenging activity compared with the other three (n-BuOH, water and petroleum ether) extracts. Free-radical-scavenging assay-guided chromatographic separation of the EtOAc extract, using a normal-phase and reverse-phase silica gel column chromatography yielded five compounds: a new triterpene named methyl 3b-O-p-hydroxy-E-cinnamoyloxy-2a,23-dihydroxyolean-12-en-28-oate (1), whose spectral data are presented for the first time, together with four known compounds, epicatechin (2), 3-trans-feruloyl maslinic acid (3), maslinic acid (4) and sucrose (5). All of the compounds were isolated from Microcos paniculata for the first time. The compounds were identified by spectroscopic methods. Among them, compound 2 displayed significant free-radical-scavenging activity which is similar to that of standard antioxidant ascorbic acid (V_C) and therefore may be a promising natural antioxidant. Full article

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Open AccessReview

Nanofabrication of Nonfouling Surfaces for Micropatterning of Cell and Microtissue

by Hidenori Otsuka

Molecules 2010, 15(8), 5525-5546; https://doi.org/10.3390/molecules15085525 - 10 Aug 2010

Cited by 29 | Viewed by 12537

Abstract

Surface engineering techniques for cellular micropatterning are emerging as important tools to clarify the effects of the microenvironment on cellular behavior, as cells usually integrate and respond the microscale environment, such as chemical and mechanical properties of the surrounding fluid and extracellular matrix, [...] Read more.

Surface engineering techniques for cellular micropatterning are emerging as important tools to clarify the effects of the microenvironment on cellular behavior, as cells usually integrate and respond the microscale environment, such as chemical and mechanical properties of the surrounding fluid and extracellular matrix, soluble protein factors, small signal molecules, and contacts with neighboring cells. Furthermore, recent progress in cellular micropatterning has contributed to the development of cell-based biosensors for the functional characterization and detection of drugs, pathogens, toxicants, and odorants. In this regards, the ability to control shape and spreading of attached cells and cell-cell contacts through the form and dimension of the cell-adhesive patches with high precision is important. Commitment of stem cells to different specific lineages depends strongly on cell shape, implying that controlled microenvironments through engineered surfaces may not only be a valuable approach towards fundamental cell-biological studies, but also of great importance for the design of cell culture substrates for tissue engineering. To develop this kind of cellular microarray composed of a cell-resistant surface and cell attachment region, micropatterning a protein-repellent surface is important because cellular adhesion and proliferation are regulated by protein adsorption. The focus of this review is on the surface engineering aspects of biologically motivated micropatterning of two-dimensional surfaces with the aim to provide an introductory overview described in the literature. In particular, the importance of non-fouling surface chemistries is discussed. Full article

(This article belongs to the Special Issue High-throughput Screening)

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Open AccessArticle

Seasonal Variation, Chemical Composition, and Analgesic and Antimicrobial Activities of the Essential Oil from Leaves of Tetradenia riparia (Hochst.) Codd in Southern Brazil

by Zilda Cristiani Gazim, Ana Carolina L. Amorim, Ana Maria C. Hovell, Claudia Moraes Rezende, Izalina Ansilieiro Nascimento, Gilberto Alves Ferreira and Diógenes Aparício Garcia Cortez

Molecules 2010, 15(8), 5509-5524; https://doi.org/10.3390/molecules15085509 - 10 Aug 2010

Cited by 87 | Viewed by 12676

Abstract

The seasonal variation of the chemical composition of the essential oil from fresh leaves of Tetradenia riparia (Hochst.) Codd grown in southern Brazil was analyzed by GC-MS, and the analgesic and antimicrobial activities of this oil were assayed. The yield of essential oil [...] Read more.

The seasonal variation of the chemical composition of the essential oil from fresh leaves of Tetradenia riparia (Hochst.) Codd grown in southern Brazil was analyzed by GC-MS, and the analgesic and antimicrobial activities of this oil were assayed. The yield of essential oil ranged from 0.17% to 0.26%, with the maximum amount in winter and the minimum in spring. The results obtained from principal components analysis (PCA) revealed the existence of high chemical variability in the different seasons. The samples were clearly discriminated into three groups: winter, autumn, and spring-summer. Samples collected during winter contained the highest percentages of calyculone (24.70%), abietadiene (13.54%), and viridiflorol (4.20%). In autumn, the major constituents were ledol (8.74%) and cis-muurolol-5-en-4-α-ol (13.78%). Samples collected in spring-summer contained the highest percentages of fenchone (12.67%), 14-hydroxy-9-epi-caryophyllene (24.36%), and α-cadinol (8.33%). Oxygenated sesquiterpenes were predominant in all the samples analyzed. The observed chemovariation might be environmentally determined by a seasonal influence. The essential oil, when given orally at a dose of 200 mg/kg, exhibited good analgesic activity on acetic acid-induced writhing in mice, inhibiting the constrictions by 38.94% to 46.13%, and this effect was not affected by seasonal variation. The antimicrobial activity of the essential oil against the bacterial strains: Staphylococcus aureus, Bacillus subtilis, Enterococcus faecalis, Escherichia coli, Salmonella enterica, Pseudomonas aeruginosa, Klebsiella pneumonia, Proteus mirabilis, Morganella morganii, and Enterobacter cloacae, and the pathogenic fungus Candida albicans was assessed by the disc diffusion method and determination of the minimum inhibitory concentration. The results obtained, followed by measurement of the minimum inhibitory concentration (MIC), indicated that S. aureus, B. subtilis, and Candida albicans were the most sensitive microorganisms, showing largest inhibition, and the lowest MIC values varied from 15.6 to 31.2 µg/mL, 7.8 to 15.6 µg/mL, and 31.2 to 62.5 µg/mL, respectively. Full article

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Open AccessReview

Preparation of Tyrian Purple (6,6′-Dibromoindigo): Past and Present

by Joel L. Wolk and Aryeh A. Frimer

Molecules 2010, 15(8), 5473-5508; https://doi.org/10.3390/molecules15085473 - 10 Aug 2010

Cited by 23 | Viewed by 19955

Abstract

Over the past century, various synthetic approaches have been suggested to the most famous dye of antiquity, Tyrian purple (6,6′-dibromoindigo). These synthetic routes have been exhaustively surveyed and critically evaluated from the perspective of convenience, cost, safety and yield. Full article

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Open AccessReview

The Application of Ribozymes and DNAzymes in Muscle and Brain

by Nikolaos P. Mastroyiannopoulos, James B. Uney and Leonidas A. Phylactou

Molecules 2010, 15(8), 5460-5472; https://doi.org/10.3390/molecules15085460 - 9 Aug 2010

Cited by 12 | Viewed by 10677

Abstract

The discovery of catalytic nucleic acids (CNAs) has provided scientists with valuable tools for the identification of new therapies for several untreated diseases through down regulation or modulation of endogenous gene expression involved in these ailments. These CNAs aim either towards the elimination [...] Read more.

The discovery of catalytic nucleic acids (CNAs) has provided scientists with valuable tools for the identification of new therapies for several untreated diseases through down regulation or modulation of endogenous gene expression involved in these ailments. These CNAs aim either towards the elimination or repair of pathological gene expression. Ribozymes, a class of CNAs, can be mostly used to down-regulate (by RNA cleavage) or repair (by RNA trans-splicing) unwanted gene expression involved in disease. DNAzymes, derived by in vitro selection processes are also able to bind and cleave RNA targets and therefore down-regulate gene expression. The purpose of this review is to present and discuss several applications of ribozymes and DNAzymes in muscle and brain. There are several diseases which affect muscle and brain and catalytic nucleic acids have been used as tools to target specific cellular transcripts involved in these groups of diseases. Full article

(This article belongs to the Special Issue Catalytic Nucleic Acids)

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Open AccessArticle

Antioxidant Activity of Butyl- and Phenylstannoxanes Derivedfrom 2-, 3- and 4-Pyridinecarboxylic Acids

by Alicia Corona-Bustamante, Juan Manuel Viveros-Paredes, Angelina Flores-Parra, Ana Lilia Peraza-Campos, Francisco J. Martínez-Martínez, María Teresa Sumaya-Martínez and Ángel Ramos-Organillo

Molecules 2010, 15(8), 5445-5459; https://doi.org/10.3390/molecules15085445 - 9 Aug 2010

Cited by 60 | Viewed by 14868

Abstract

In vitro antioxidant activity for 12 stannoxanes derived from Ph₃SnCl (compounds 1-3), Ph₂SnCl₂ (compounds 4-6), Bu₃SnCl (compounds 7-9), and Bu₂SnCl₂ (compounds 10-12 [...] Read more.

In vitro antioxidant activity for 12 stannoxanes derived from Ph₃SnCl (compounds 1-3), Ph₂SnCl₂ (compounds 4-6), Bu₃SnCl (compounds 7-9), and Bu₂SnCl₂ (compounds 10-12), was assayed qualitatively by the chromatographic profile with 1,1-diphenyl-2-picrylhydrazil (DPPH) method and by two quantitative methods: the DPPH radical scavenging activity and Ferric-Reducing Antioxidant Power (FRAP) assays. The results were compared with those obtained with the starting materials 2-pyridine- carboxylic acid (I), 3-pyridinecarboxylic acid (II) and 4-pyridinecarboxylic acid (III), as well as with standard compounds, such as vitamin C and vitamin E, respectively. The in vitro antiradical activity with DPPH of diphenyltin derivative 5 showed a very similar behavior to vitamin C at a 20 µg/mL concentration, whereas according to the FRAP method, compound 8 was better. This difference is due to the mechanism of the antioxidant process. The Structure-Activity Relationships (SAR) for both methods is also reported. Full article

(This article belongs to the Special Issue Antioxidants)

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Molecular Evolution of Functional Nucleic Acids with Chemical Modifications

by Masayasu Kuwahara and Naoki Sugimoto

Molecules 2010, 15(8), 5423-5444; https://doi.org/10.3390/molecules15085423 - 9 Aug 2010

Cited by 121 | Viewed by 14913

Abstract

Nucleic acids are attractive materials for creating functional molecules that have applications as catalysts, specific binders, and molecular switches. Nucleic acids having such functions can be obtained by random screening, typically using in vitro selection methods. These methods have helped explore the potential [...] Read more.

Nucleic acids are attractive materials for creating functional molecules that have applications as catalysts, specific binders, and molecular switches. Nucleic acids having such functions can be obtained by random screening, typically using in vitro selection methods. These methods have helped explore the potential abilities of nucleic acids and steadily contributed to their evolution, i.e., creation of RNA/DNA enzymes, aptamers, and aptazymes. Chemical modification would be a key means to further increase their performance, e.g., expansion of function diversity, enhancement of activity, and improvement of biostability for biological use. Indeed, in the past two decades, random screening involving chemical modification, post-SELEX chemical modification, and rational design methods have been advanced, and combining and integrating these methods may produce a new class of functional nucleic acids. This review focuses on the effectiveness of chemical modifications on the evolution of nucleic acids as functional molecules and the outlook for related technologies. Full article

(This article belongs to the Special Issue Catalytic Nucleic Acids)

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Open AccessArticle

Using Topological Indices to Predict Anti-Alzheimer and Anti-Parasitic GSK-3 Inhibitors by Multi-Target QSAR in Silico Screening

by Isela García, Yagamare Fall and Generosa Gómez

Molecules 2010, 15(8), 5408-5422; https://doi.org/10.3390/molecules15085408 - 9 Aug 2010

Cited by 52 | Viewed by 8036

Abstract

Plasmodium falciparum, Leishmania, Trypanosomes, are the causers of diseases such as malaria, leishmaniasis and African trypanosomiasis that nowadays are the most serious parasitic health problems worldwide. The great number of deaths and the few drugs available against these parasites, make [...] Read more.

Plasmodium falciparum, Leishmania, Trypanosomes, are the causers of diseases such as malaria, leishmaniasis and African trypanosomiasis that nowadays are the most serious parasitic health problems worldwide. The great number of deaths and the few drugs available against these parasites, make necessary the search for new drugs. Some of these antiparasitic drugs also are GSK-3 inhibitors. GSKI-3 are candidates to develop drugs for the treatment of Alzheimer’s disease. In this work topological descriptors for a large series of 3,370 active/non-active compounds were initially calculated with the ModesLab software. Linear Discriminant Analysis was used to fit the classification function and it predicts heterogeneous series of compounds like paullones, indirubins, meridians, etc. This study thus provided a general evaluation of these types of molecules. Full article

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

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Hammerhead Ribozymes: True Metal or Nucleobase Catalysis? Where Is the Catalytic Power from?

by Fabrice Leclerc

Molecules 2010, 15(8), 5389-5407; https://doi.org/10.3390/molecules15085389 - 6 Aug 2010

Cited by 18 | Viewed by 10600

Abstract

The hammerhead ribozyme was first considered as a metalloenzyme despite persistent inconsistencies between structural and functional data. In the last decade, metal ions were confirmed as catalysts in self-splicing ribozymes but displaced by nucleobases in self-cleaving ribozymes. However, a model of catalysis just [...] Read more.

The hammerhead ribozyme was first considered as a metalloenzyme despite persistent inconsistencies between structural and functional data. In the last decade, metal ions were confirmed as catalysts in self-splicing ribozymes but displaced by nucleobases in self-cleaving ribozymes. However, a model of catalysis just relying on nucleobases as catalysts does not fully fit some recent data. Gathering and comparing data on metal ions in self-cleaving and self-splicing ribozymes, the roles of divalent metal ions and nucleobases are revisited. Hypothetical models based on cooperation between metal ions and nucleobases are proposed for the catalysis and evolution of this prototype in RNA catalysis. Full article

(This article belongs to the Special Issue Catalytic Nucleic Acids)

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Molecules, Volume 15, Issue 8 (August 2010) – 49 articles , Pages 5066-5839

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