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235 KiB

Open AccessArticle

Enantio and Diastereoselective Addition of Phenylacetylene to Racemic α-chloroketones

by Silvia Alesi, Enrico Emer, Montse Guiteras Capdevila, Diego Petruzziello, Andrea Gualandi and Pier Giorgio Cozzi

Molecules 2011, 16(6), 5298-5314; https://doi.org/10.3390/molecules16065298 - 23 Jun 2011

Cited by 6 | Viewed by 7557

Abstract

In this report, we have presented the first diastereoselective addition of phenylacetylene to chiral racemic chloroketones. The addition is controlled by the reactivity of the chloroketones that allowed the stereoselective reaction to be performed at –20 °C. Chiral racemic chloroketones are used in the reaction. By carefully controlling the temperature and the reaction time we were able to isolate the corresponding products in moderate yields and with good, simple and predictable facial stereoselection. Our reaction is a rare example of the use of chiral ketones in an enantioselective alkynylation reaction and opens new perspectives for the formation of chiral quaternary stereocenters. Full article

(This article belongs to the Special Issue Catalytic Asymmetric Synthesis)

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341 KiB

Open AccessReview

The Main Anticancer Bullets of the Chinese Medicinal Herb, Thunder God Vine

by Zi Liu, Liang Ma and Guang-Biao Zhou

Molecules 2011, 16(6), 5283-5297; https://doi.org/10.3390/molecules16065283 - 23 Jun 2011

Cited by 113 | Viewed by 16209

Abstract

The thunder god vine or Tripterygium wilfordii Hook. F. is a representative Chinese medicinal herb which has been used widely and successfully for centuries in treating inflammatory diseases. More than 100 components have been isolated from this plant, and most of them have potent therapeutic efficacy for a variety of autoimmune and inflammatory diseases. In the past four decades, the anticancer activities of the extracts from this medicinal herb have attracted intensive attention by researchers worldwide. The diterpenoid epoxide triptolide and the quinone triterpene celastrol are two important bioactive ingredients that show a divergent therapeutic profile and can perturb multiple signal pathways. Both compounds promise to turn traditional medicines into modern drugs. In this review, we will mainly address the anticancer activities and mechanisms of action of these two agents and briefly describe some other antitumor components of the thunder god vine. Full article

(This article belongs to the Collection Bioactive Compounds)

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653 KiB

Open AccessArticle

Acute Oral Toxicity of Methanolic Seed Extract of Cassia fistula in Mice

by Subramanion L. Jothy, Zuraini Zakaria, Yeng Chen, Yee Ling Lau, Lachimanan Yoga Latha and Sreenivasan Sasidharan

Molecules 2011, 16(6), 5268-5282; https://doi.org/10.3390/molecules16065268 - 23 Jun 2011

Cited by 158 | Viewed by 15546

Abstract

Background and objective: Cassia fistula is widely used in traditional medicine to treat various types of ailments. The evaluation of toxic properties of C. fistula is crucial when considering public health protection because exposure to plant extracts can result in undesirable effects on consumers. Hence, in this study the acute oral toxicity of C. fistula seeds extract was investigated in mice. Results: Oral administration of crude extract at the highest dose of 5000 mg/kg resulted in no mortalities or evidence of adverse effects, implying that C. fistula in nontoxic. Throughout 14 days of the treatment no changes in behavioural pattern, clinical sign and body weight of mice in both control and treatment groups. Also there were no any significant elevations observed in the biochemical analysis of the blood serum. Further, histopathological examination revealed normal architecture and no significant adverse effects observed on the kidney, heart, liver, lung and spleen. Conclusions: Overall, the results suggest that, the oral administration of C. fistula methanolic seeds extract did not produce any significant toxic effect in mice. Hence, the extract can be utilized for pharmaceutical formulations. Full article

(This article belongs to the Special Issue Alkaloids: Novel Therapeutic Perspectives)

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845 KiB

Open AccessReview

Recent Advances in the Synthesis of N-Containing Heteroaromatics via Heterogeneously Transition Metal Catalysed Cross-Coupling Reactions

by Laurent Djakovitch, Nelly Batail and Marie Genelot

Molecules 2011, 16(6), 5241-5267; https://doi.org/10.3390/molecules16065241 - 23 Jun 2011

Cited by 49 | Viewed by 9931

Abstract

N-containing heteroaromatics are important substructures found in numerous natural or synthetic alkaloids. The diversity of the structures encountered, as well as their biological and pharmaceutical relevance, have motivated research aimed at the development of new economical, efficient and selective synthetic strategies to access these compounds. Over more than 100 years of research, this hot topic has resulted in numerous so-called “classical synthetic methods” that have really contributed to this important area. However, when the selective synthesis of highly functional heteroaromatics like indoles, quinolones, indoxyls, etc. is considered these methods remain limited. Recently transition metal-catalysed (TM-catalysed) procedures for the synthesis of such compounds and further transformations, have been developed providing increased tolerance toward functional groups and leading generally to higher reaction yields. Many of these methods have proven to be the most powerful and are currently applied in target- or diversity-oriented syntheses. This review article aims at reporting the recent developments devoted to this important area, focusing on the use of heterogeneous catalysed procedures that include either the formation of the heterocyclic ring towards the nuclei or their transformations to highly substituted compounds. Full article

(This article belongs to the Special Issue Cross-Coupling Reactions in Organic Synthesis)

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187 KiB

Open AccessArticle

Maleimido-Functionalized NOTA Derivatives as Bifunctional Chelators for Site-Specific Radiolabeling

by Christian Förster, Maik Schubert, Hans-Jürgen Pietzsch and Jörg Steinbach

Molecules 2011, 16(6), 5228-5240; https://doi.org/10.3390/molecules16065228 - 22 Jun 2011

Cited by 10 | Viewed by 9251

Abstract

Two basic and simple synthetic routes for mono- and bis-maleimide bearing 1,4,7-triazacyclononane-N,N’,N’’-triacetic acid (NOTA) chelators as new bifunctional chelators are described. The syntheses are characterized by their simplicity and short reaction times, as well as practical purification methods and acceptable to very good chemical yields. The usefulness of these two synthetic pathways is demonstrated by the preparation of a set of mono- and bis-maleimide functionalized NOTA derivatives. In conclusion, these two methods can easily be expanded to the syntheses of further tailored maleimide-NOTA chelators for diverse applications. Full article

(This article belongs to the Section Organic Chemistry)

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219 KiB

Open AccessArticle

Synthesis and Characterization of (Z)-5-Arylmethylidene-rhodanines with Photosynthesis-Inhibiting Properties

by Veronika Opletalova, Jan Dolezel, Katarina Kralova, Matus Pesko, Jiri Kunes and Josef Jampilek

Molecules 2011, 16(6), 5207-5227; https://doi.org/10.3390/molecules16065207 - 22 Jun 2011

Cited by 24 | Viewed by 7004

Abstract

A series of rhodanine derivatives was prepared. The synthetic approach, analytical and spectroscopic data of all synthesized compounds are presented. Lipophilicity of all the discussed rhodanine derivatives was analyzed using the RP-HPLC method. The compounds were tested for their ability to inhibit photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts and reduce chlorophyll content in freshwater alga Chlorella vulgaris. Structure-activity relationships between the chemical structure, physical properties and biological activities of the evaluated compounds are discussed. For majority of the tested compounds the lipophilicity of the compound and not electronic properties of the R¹ substituent were decisive for PET-inhibiting activity. The most potent PET inhibitor was (5Z)-5-(4-bromobenzylidene)-2-thioxo-1,3-thiazolidin-4-one (IC₅₀ = 3.0 μmol/L) and the highest antialgal activity was exhibited by (5Z)-5-(4-chlorobenzylidene)-2-thioxo-1,3-thiazolidin-4-one (IC₅₀ = 1.3 μmol/L). Full article

(This article belongs to the Special Issue ECSOC-11)

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307 KiB

Open AccessArticle
Microwave-Assisted Solution-Phase Synthesis and DART-Mass Spectrometric Monitoring of a Combinatorial Library of Indolin-2,3-dione Schiff Bases with Potential Antimycobacterial Activity
by Tarek Aboul-Fadl, Hatem A. Abdel-Aziz, Adnan Kadi, Pervez Ahmad, Tilal Elsaman, Mohamed W. Attwa and Ibrahim A. Darwish

Molecules 2011, 16(6), 5194-5206; https://doi.org/10.3390/molecules16065194 - 22 Jun 2011
Cited by 9 | Viewed by 8372
Abstract
A combinatorial library composed of eleven hydrazides A-K and eleven indolin-1,2-dione derivatives 1-11 has been designed to formally generate sublibraries of 22 mixtures, M₁-M₂₂ comprising of 121 Schiff bases, A-K(1-11). The designed library has been synthesized by [...] Read more.

A combinatorial library composed of eleven hydrazides A-K and eleven indolin-1,2-dione derivatives 1-11 has been designed to formally generate sublibraries of 22 mixtures, M₁-M₂₂ comprising of 121 Schiff bases, A-K(1-11). The designed library has been synthesized by the solution-phase method and microwave-assisted synthetic techniques. The formation of individual compounds of each mixture was confirmed by Direct Analysis in Real Time (DART) as ionization technique connected to an Ion Trap as a mass detector. The synthesized mixtures were evaluated for their antimycobacterial activity against four Mycobacterium strains; M. intercellulari, M. xenopi, M. cheleneoi and M. smegmatis. Variable antimycobacterial activity was revealed with the investigated mixtures and maximum activity was shown by M₈, M₁₀, M₁₁, and M₁₅ with MIC values of 1.5, 3.1, 6.2 and 0.09 μg/mL, respectively. Application of the indexed method of analysis on these active mixtures revealed that compounds D₈, D₁₀ and D₁₁ may contribute to the activity of the tested mixtures. Full article

(This article belongs to the Section Medicinal Chemistry)

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223 KiB

Open AccessArticle
Synthesis of Some Novel Pyrazolo[1,5-a]pyrimidine Derivatives and Their Application as Disperse Dyes
by Alya M. Al-Etaibi, Nouria A. Al-Awadi, Morsy A. El-Apasery and Maher R. Ibrahim

Molecules 2011, 16(6), 5182-5193; https://doi.org/10.3390/molecules16065182 - 22 Jun 2011
Cited by 32 | Viewed by 8689
Abstract
A series of novel monoazo-disperse dyes containing pyrazolo[1,5-a]pyrimidine structures were synthesized starting with the coupling reaction between ethyl cyanoacetate and 4-hydroxybenzenediazonium chloride, followed by treatment of the resulting hydrazone product with hydrazine hydrate. The pyrazolohydrazone 6 is then treated with either 2,4-pentandione and [...] Read more.

A series of novel monoazo-disperse dyes containing pyrazolo[1,5-a]pyrimidine structures were synthesized starting with the coupling reaction between ethyl cyanoacetate and 4-hydroxybenzenediazonium chloride, followed by treatment of the resulting hydrazone product with hydrazine hydrate. The pyrazolohydrazone 6 is then treated with either 2,4-pentandione and enaminonitrile or aryl-substituted enaminoketones to give the target pyrazolo[1,5-a]pyrimidine dyes 7 and 15a-d. Structural assignments to the dyes were made using NMR spectroscopic methods. A new high temperature method, using microwave heating, was employed to apply these dyes to polyester fibers. Most of the dyed fabrics tested displayed moderate light fastness and excellent washing fastness properties. Full article

(This article belongs to the Section Organic Chemistry)

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408 KiB

Open AccessArticle
Identification of N⁶,N⁶-Dimethyladenosine in Transfer RNA from Mycobacterium bovis Bacille Calmette-Guérin
by Clement T.Y. Chan, Yok Hian Chionh, Chia-Hua Ho, Kok Seong Lim, I. Ramesh Babu, Emily Ang, Lin Wenwei, Sylvie Alonso and Peter C. Dedon

Molecules 2011, 16(6), 5168-5181; https://doi.org/10.3390/molecules16065168 - 21 Jun 2011
Cited by 25 | Viewed by 8138
Abstract
There are more than 100 different ribonucleoside structures incorporated as post-transcriptional modifications, mainly in tRNA and rRNA of both prokaryotes and eukaryotes, and emerging evidence suggests that these modifications function as a system in the translational control of cellular responses. However, our understanding [...] Read more.

There are more than 100 different ribonucleoside structures incorporated as post-transcriptional modifications, mainly in tRNA and rRNA of both prokaryotes and eukaryotes, and emerging evidence suggests that these modifications function as a system in the translational control of cellular responses. However, our understanding of this system is hampered by the paucity of information about the complete set of RNA modifications present in individual organisms. To this end, we have employed a chromatography-coupled mass spectrometric approach to define the spectrum of modified ribonucleosides in microbial species, starting with Mycobacterium bovis BCG. This approach revealed a variety of ribonucleoside candidates in tRNA from BCG, of which 12 were definitively identified based on comparisons to synthetic standards and 5 were tentatively identified by exact mass comparisons to RNA modification databases. Among the ribonucleosides observed in BCG tRNA was one not previously described in tRNA, which we have now characterized as N⁶,N⁶-dimethyladenosine. Full article

(This article belongs to the Special Issue Nucleoside Analogues)

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182 KiB

Open AccessArticle
Inhibitory Activity of Flavonoids against Class I Phosphatidylinositol 3-Kinase Isoforms
by Dexin Kong, Yanwen Zhang, Takao Yamori, Hongquan Duan and Meihua Jin

Molecules 2011, 16(6), 5159-5167; https://doi.org/10.3390/molecules16065159 - 21 Jun 2011
Cited by 27 | Viewed by 6742
Abstract
Class I PI3 Kinase (PI3K) phosphorylates phosphatidylinositol 4,5-bisphophate (PIP2) to generate the second messenger phosphatidylinositol 3,4,5-trisphosphate (PIP3) and therefore plays an important role in fundamental cellular responses such as proliferation. There are four isoforms of class I PI3K which are known to have [...] Read more.

Class I PI3 Kinase (PI3K) phosphorylates phosphatidylinositol 4,5-bisphophate (PIP2) to generate the second messenger phosphatidylinositol 3,4,5-trisphosphate (PIP3) and therefore plays an important role in fundamental cellular responses such as proliferation. There are four isoforms of class I PI3K which are known to have different functions and relate to various diseases such as cancer and inflammation. Flavonoids are abundant in fruits, vegetables and plant-derived beverages such as tea. So far, various pharmacological effects of flavonoids have been reported. We previously reported that the flavonoid baicalein exhibits potent PI3K-inhibitory activity. Recently we examined the inhibitory activity of eighteen flavonoids against PI3Ka by using an in vitro homogenous time resolved fluorescence (HTRF) kinase assay, and deduced their structure-activity relationships by comparing the activities of the analogues. Our result suggests that the number of hydroxyl groups in the A and B rings might promote the activity, while loss of C2-C3 double bond might reduce the activity. Furthermore, the activity against 4 class I PI3K isoforms of some selected flavonoids was investigated, and the results indicate that the flavonoids seem to exhibit more potent activity on PI3Ka and d isoforms compared with that on PI3Kb and g isoforms. Full article

(This article belongs to the Section Natural Products Chemistry)

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118 KiB

Open AccessArticle
Phytochemical Analysis and In Vitro Antimicrobial and Free-Radical-Scavenging Activities of the Essential Oils from Euryops arabicus and Laggera decurrens
by Ramzi A. Mothana, Mansour S. Alsaid and Nawal M. Al-Musayeib

Molecules 2011, 16(6), 5149-5158; https://doi.org/10.3390/molecules16065149 - 21 Jun 2011
Cited by 24 | Viewed by 8235
Abstract
The essential oils of the aerial part of two Asteraceae species, namely Euryops arabicus Steud. and Laggera decurrens (Vahl.) Hepper and Wood, were studied by GC and GC/MS. In parallel the antimicrobial and antioxidant activities were evaluated. The investigation led to the identification [...] Read more.

The essential oils of the aerial part of two Asteraceae species, namely Euryops arabicus Steud. and Laggera decurrens (Vahl.) Hepper and Wood, were studied by GC and GC/MS. In parallel the antimicrobial and antioxidant activities were evaluated. The investigation led to the identification of 48 and 44 compounds for both plants, respectively. The essential oil of E. arabicus was rich in oxygenated sesquiterpenes (39.9%). The oil also contained a high content of sesquiterpene hydrocarbons (24.1%). Compounds such as caryophyllene oxide (8.6%), T-cadinol (7.0%), spathulenol (5.2%), (E)-β-caryophyllene (6.0%) and 2-epi-(E)-β-caryophyllene (6.0%) were the main constituents of the oil. Oxygenated monoterpenes also predominated in L. decurrens (46.3%). The thymoquinone-derivative, 3-methoxy-2-methyl-5-(1-methylethyl)-2,5-cyclohexadiene-1,4-dione (28.1%), thymol (5.7%) and eudesma-11-en-4a-ol (7.0%) were the most abundant constituents. Both essential oils showed antimicrobial activity with MIC-values between 0.13–5.25 mg/mL. Furthermore, only the essential oil of L. decurrens exhibited a strong antioxidant activity (91%) at 500 µg/mL. Full article

(This article belongs to the Section Natural Products Chemistry)

170 KiB

Open AccessArticle
Reactions of Some New Thienothiophene Derivatives
by Yahia Nasser Mabkhot, Abdullah Mohammad Al-Majid, Abdullah Saleh Alamary, Ismail Warad and Yamin Sedigi

Molecules 2011, 16(6), 5142-5148; https://doi.org/10.3390/molecules16065142 - 21 Jun 2011
Cited by 9 | Viewed by 7029
Abstract
Facile and convenient syntheses of bisdimethylthieno[2,3-b]thiophen-2,5-diyl bis(oxazole-2-amine), bis(1H-imidazol-2-amine), bis((3a)-H-indole),[1,2-a]pyrimidine), bis(1H-imidazo[1,2-b][1,2,4]triazole) and bis(9H-benzo[d]imidazo[1,2-a]imidazole) derivatives incorporating a thieno[2,3-b]thiophene moiety from the versatile and readily accessible 1,1'(3,4-dimethylthieno[2,3-b]thiophene-2,5-diyl)-bis(2-bromo-ethanone) (1) are described. Full article

(This article belongs to the Special Issue Chemical Libraries)

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292 KiB

Open AccessArticle
Synthesis and Cytotoxic Evaluation of Novel N-Methyl-4-phenoxypicolinamide Derivatives
by Wei Li, Xin Zhai, Lu Ding, Limin Sun, Xiaomei Chen, Ping Gong and Tiemin Sun

Molecules 2011, 16(6), 5130-5141; https://doi.org/10.3390/molecules16065130 - 20 Jun 2011
Cited by 2 | Viewed by 6818
Abstract
A series of N-methyl-4-phenoxypicolinamide derivatives were synthesized and evaluated in vitro for their cytotoxic activity against A549, H460 and HT29 cell lines. Pharmacological data indicated that some of the target compounds possessed marked antiproliferative activity, superior to that of the reference drug [...] Read more.

A series of N-methyl-4-phenoxypicolinamide derivatives were synthesized and evaluated in vitro for their cytotoxic activity against A549, H460 and HT29 cell lines. Pharmacological data indicated that some of the target compounds possessed marked antiproliferative activity, superior to that of the reference drug sorafenib. As the most promising compound, 8e exhibited potent cytotoxicity with the IC₅₀ value of 3.6, 1.7 and 3.0 μM against A549, H460 and HT-29 cell lines, respectively. Full article

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221 KiB

Open AccessArticle
Methoxymethyl (MOM) Group Nitrogen Protection of Pyrimidines Bearing C-6 Acyclic Side-Chains
by Tatjana Gazivoda Kraljević, Martina Petrović, Svjetlana Krištafor, Damjan Makuc, Janez Plavec, Tobias L. Ross, Simon M. Ametamey and Silvana Raić-Malić

Molecules 2011, 16(6), 5113-5129; https://doi.org/10.3390/molecules16065113 - 20 Jun 2011
Cited by 6 | Viewed by 8301
Abstract
Novel N-methoxymethylated (MOM) pyrimidine (4-13) and pyrimidine-2,4-diones (15-17) nucleoside mimetics in which an isobutyl side-chain is attached at the C-6 position of the pyrimidine moiety were synthesized. Synthetic methods via O-persilylated or N [...] Read more.

Novel N-methoxymethylated (MOM) pyrimidine (4-13) and pyrimidine-2,4-diones (15-17) nucleoside mimetics in which an isobutyl side-chain is attached at the C-6 position of the pyrimidine moiety were synthesized. Synthetic methods via O-persilylated or N-anionic uracil derivatives have been evaluated for the synthesis of N-1- and/or N-3-MOM pyrimidine derivatives with C-6 acyclic side-chains. A synthetic approach using an activated N-anionic pyrimidine derivative afforded the desired N,N-1,3-diMOM and N-1-MOM pyrimidines 4 and 5 in good yield. Introduction of fluorine into the side-chain was performed with DAST as the fluorinating reagent to give a N,N-1,3-diMOM pyrimidine 13 with a 1-fluoro-3-hydroxyisobutyl moiety at C-6. Conformational study of the monotritylated N-1-MOM pyrimidine 12 by the use of the NOE experiments revealed the predominant conformation of the compound to be one where the hydroxymethyl group in the C-6 side-chain is close to the N-1-MOM moiety, while the OMTr is in proximity to the CH₃-5 group. Contrary to this no NOE enhancements between the N-1-MOM group and hydroxymethyl or fluoromethyl protons in 13 were observed, which suggested a nonrestricted rotation along the C-6 side-chain. Fluorinated N,N-1,3-diMOM pyrimidine 13 emerged as a model compound for development of tracer molecules for non-invasive imaging of gene expression using positron emission tomography (PET). Full article

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175 KiB

Open AccessArticle
Characteristic Aroma Compounds from Different Pineapple Parts
by Chang-Bin Wei, Sheng-Hui Liu, Yu-Ge Liu, Ling-Ling Lv, Wen-Xiu Yang and Guang-Ming Sun

Molecules 2011, 16(6), 5104-5112; https://doi.org/10.3390/molecules16065104 - 20 Jun 2011
Cited by 58 | Viewed by 11397
Abstract
Characteristic aroma volatile compounds from different parts of cayenne pineapple were analyzed by headspace-solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC/MS). The main volatile compounds were esters, terpenes, ketones and aldehydes. The number and content of aroma compounds detected in pulp were [...] Read more.

Characteristic aroma volatile compounds from different parts of cayenne pineapple were analyzed by headspace-solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC/MS). The main volatile compounds were esters, terpenes, ketones and aldehydes. The number and content of aroma compounds detected in pulp were higher than those found in core. In pulp, the characteristic aroma compounds were ethyl 2-methylbutanoate, ethyl hexanoate, 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF), decanal, ethyl 3-(methylthio)propionate, ethyl butanoate, and ethyl (E)-3-hexenoate; while in core the main compounds were ethyl 2-methylbutanoate, ethyl hexanoate and DMHF. The highest odor units were found to correspond to ethyl 2-methylbutanoate, followed by ethyl hexanoate and DMHF. The odor units found for pulp were higher than those for core. Full article

(This article belongs to the Section Natural Products Chemistry)

699 KiB

Open AccessArticle
Crystallization and Characterization of an Inflammatory Lectin Purified from the Seeds of Dioclea wilsonii
by Thaiz Batista Azevedo Rangel, Ana Maria Sampaio Assreuy, Alana de Freitas Pires, Amanda Uliana de Carvalho, Raquel Guimarães Benevides, Rafael da Conceição Simões, Helton Colares da Silva, Maria Júlia Barbosa Bezerra, Antonia Samia Fernandes do Nascimento, Kyria Santiago do Nascimento, Celso Shiniti Nagano, Alexandre Holanda Sampaio, Plínio Delatorre, Bruno Anderson Matias da Rocha, Patricia Machado Bueno Fernandes and Benildo Sousa Cavada

Molecules 2011, 16(6), 5087-5103; https://doi.org/10.3390/molecules16065087 - 20 Jun 2011
Cited by 20 | Viewed by 9557
Abstract
DwL, a lectin extracted from the seeds of Dioclea wilsonii, is a metalloprotein with strong agglutinating activity against rabbit and ABO erythrocytes, inhibited by glucose and mannose. DwL was purified by affinity chromatography on a Sephadex G-50 column and ion exchange chromatography [...] Read more.

DwL, a lectin extracted from the seeds of Dioclea wilsonii, is a metalloprotein with strong agglutinating activity against rabbit and ABO erythrocytes, inhibited by glucose and mannose. DwL was purified by affinity chromatography on a Sephadex G-50 column and ion exchange chromatography on a HiTrap SP XL column. SDS-PAGE revealed three electrophoretic bands corresponding to the α (25,634 ± 2 Da), β (12,873 ± 2 Da) and γ (12,779 ± 2 Da) chains. Protein sequencing was done by Tandem Mass Spectrometry. The primary sequence featured 237 amino acids and was highly homologous to other reported Diocleinae lectins. A complete X-ray dataset was collected at 2.0 Å for X-Man-complexed DWL crystals produced by the vapor diffusion method. The crystals were orthorhombic and belonged to the space group I222, with the unit-cell parameters a = 59.6, b = 67.9 and c = 109.0 Å. DWL differed in potency from other ConA-like lectins and was found to induce neutrophil migration in rats, making it particularly useful in structural/functional studies of this class of proteins. Full article

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252 KiB

Open AccessArticle
Nematocidal Flavone-C-Glycosides against the Root-Knot Nematode (Meloidogyne incognita) from Arisaema erubescens Tubers
by Shu Shan Du, Hai Ming Zhang, Chun Qi Bai, Cheng Fang Wang, Qi Zhi Liu, Zhi Long Liu, Yong Yan Wang and Zhi Wei Deng

Molecules 2011, 16(6), 5079-5086; https://doi.org/10.3390/molecules16065079 - 20 Jun 2011
Cited by 52 | Viewed by 9734
Abstract
A screening of several Chinese medicinal herbs for nematicidal properties showed that Arisaema erubescens (Wall.) Schott tubers possessed significant nematicidal activity against the root-knot nematode (Meloidogyne incognita). From the ethanol extract, two nematicidal flavone-C-glycosides were isolated by bioassay-guided fractionation. [...] Read more.

A screening of several Chinese medicinal herbs for nematicidal properties showed that Arisaema erubescens (Wall.) Schott tubers possessed significant nematicidal activity against the root-knot nematode (Meloidogyne incognita). From the ethanol extract, two nematicidal flavone-C-glycosides were isolated by bioassay-guided fractionation. The compounds were identified as schaftoside and isoschaftoside on the basis of their phytochemical and spectral data. Schaftoside and isoschaftoside possessed strong nematicidal activity against M. incognita (LC₅₀ = 114.66 μg/mL and 323.09 μg/mL, respectively) while the crude extract of A. erubescens exhibited nematicidal activity against the root-knot nematode with a LC₅₀ value of 258.11 μg/mL. Full article

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206 KiB

Open AccessArticle
Two-Carbon Homologation of Aldehydes and Ketones to α,β-Unsaturated Aldehydes
by Richard J. Petroski, Karl Vermillion and Allard A. Cossé

Molecules 2011, 16(6), 5062-5078; https://doi.org/10.3390/molecules16065062 - 17 Jun 2011
Cited by 11 | Viewed by 7343
Abstract
Phosphonate reagents were developed for the two-carbon homologation of aldehydes or ketones to unbranched- or methyl-branched α,β-unsaturated aldehydes. The phosphonate reagents, diethyl methylformyl-2-phosphonate dimethylhydrazone and diethyl ethylformyl-2-phosphonate dimethylhydrazone, contained a protected aldehyde group instead of the usual ester group. A homologation cycle entailed [...] Read more.

Phosphonate reagents were developed for the two-carbon homologation of aldehydes or ketones to unbranched- or methyl-branched α,β-unsaturated aldehydes. The phosphonate reagents, diethyl methylformyl-2-phosphonate dimethylhydrazone and diethyl ethylformyl-2-phosphonate dimethylhydrazone, contained a protected aldehyde group instead of the usual ester group. A homologation cycle entailed condensation of the reagent with the starting aldehyde, followed by removal of the dimethylhydrazone protective group with a biphasic mixture of 1 M HCl and petroleum ether. This robust two-step process worked with a variety of aldehydes and ketones. Overall isolated yields of unsaturated aldehyde products ranged from 71% to 86% after the condensation and deprotection steps. Full article

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

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262 KiB

Open AccessArticle
Cholesterol-Lowering Activity of the Major Polyphenols in Grape Seed
by Sathaporn Ngamukote, Kittana Mäkynen, Thavaree Thilawech and Sirichai Adisakwattana

Molecules 2011, 16(6), 5054-5061; https://doi.org/10.3390/molecules16065054 - 17 Jun 2011
Cited by 163 | Viewed by 18268
Abstract
The major polyphenols in grape seed have been shown to have beneficial health effects in the prevention of dyslipidemia and cardiovascular diseases. In this present study, we investigated the cholesterol-lowering activity of three major polyphenolic compounds found in grape seed. The results showed [...] Read more.

The major polyphenols in grape seed have been shown to have beneficial health effects in the prevention of dyslipidemia and cardiovascular diseases. In this present study, we investigated the cholesterol-lowering activity of three major polyphenolic compounds found in grape seed. The results showed that gallic acid, catechin, and epicatechin significantly inhibited pancreatic cholesterol esterase in a concentration-dependent manner. Moreover, they bound to taurocholic acid, taurodeoxycholic acid, and glycodeoxycholic acid at levels ranging from 38.6% to 28.2%. At the concentration of 0.2 mg/mL, gallic acid, catechin, and epicatechin reduced the formation of cholesterol micelles 27.26 ± 2.17%, 11.88 ± 0.75%, and 19.49 ± 3.71%, respectively. These findings clearly demonstrate that three major polyphenolic compounds present in a particular grape seed have cholesterol-lowering activity by inhibiting pancreatic cholesterol esterase, binding of bile acids, and reducing solubility of cholesterol in micelles which may result in delayed cholesterol absorption. Full article

(This article belongs to the Section Natural Products Chemistry)

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2708 KiB

Open AccessArticle
Synthetic Dye - Inorganic Salt Hybrid Colorants for Application in Thermoplastics
by Yan-Ping Wei, Tian Li and Hong-Wen Gao

Molecules 2011, 16(6), 5035-5053; https://doi.org/10.3390/molecules16065035 - 17 Jun 2011
Cited by 4 | Viewed by 6613
Abstract
Common synthetic dyes, e.g., Weak Acid Pink Red B (APRB, C.I. 18073), Mordant Blue 9 (MB, C.I.14855) and Acid Brilliant Blue 6B (ABB6B, C.I. 42660), can be removed from water by in situ hybridization with CaCO₃, BaSO₄ and Ca₃ [...] Read more.

Common synthetic dyes, e.g., Weak Acid Pink Red B (APRB, C.I. 18073), Mordant Blue 9 (MB, C.I.14855) and Acid Brilliant Blue 6B (ABB6B, C.I. 42660), can be removed from water by in situ hybridization with CaCO₃, BaSO₄ and Ca₃(PO₄)₂ and the resulting hybrids thus prepared used as plastic colorants. All the hybrids can be processed into polypropylene (PP) at 200 °C with good color intensity, color brightness and homogeneous dispersion. The BaSO₄-MB hybrid exhibits better migration resistance to acid and alkali, and stronger covering power than the BaSO₄-MB mixture. The thermal stability and UV resistance of the Ca₃(PO₄)₂-ABB6B hybrid are better than those of the Ca₃(PO₄)₂-ABB6B mixture. The crystallinity of PP is enhanced by incorporation of these hybrids and the use of these hybrids as colorants in PP instead of the dyes alone is determined to be feasible. Full article

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266 KiB

Open AccessArticle
Ru/Me-BIPAM-Catalyzed Asymmetric Addition of Arylboronic Acids to Aliphatic Aldehydes and α-Ketoesters
by Yasunori Yamamoto, Tomohiko Shirai, Momoko Watanabe, Kazunori Kurihara and Norio Miyaura

Molecules 2011, 16(6), 5020-5034; https://doi.org/10.3390/molecules16065020 - 17 Jun 2011
Cited by 58 | Viewed by 8411
Abstract
A ruthenium-catalyzed asymmetric arylation of aliphatic aldehydes and α-ketoesters with arylboronic acids has been developed, giving chiral alkyl(aryl)methanols and α-hydroxy esters in good yields. The use of a chiral bidentate phosphoramidite ligand (Me-BIPAM) achieved excellent enantioselectivities. Full article

(This article belongs to the Special Issue Catalytic Asymmetric Synthesis)

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211 KiB

Open AccessArticle
Enantioselective Evans-Tishchenko Reduction of b-Hydroxyketone Catalyzed by Lithium Binaphtholate
by Tomonori Ichibakase, Masato Nakatsu and Makoto Nakajima

Molecules 2011, 16(6), 5008-5019; https://doi.org/10.3390/molecules16065008 - 17 Jun 2011
Cited by 7 | Viewed by 6992
Abstract
Lithium diphenylbinaphtholate catalyzed the enantioselective Evans-Tishchenko reduction of achiral b-hydroxyketones to afford monoacyl-protected 1,3-diols with high stereoselectivities. In the reaction of racemic b-hydroxyketones, kinetic optical resolution occurred in a highly stereoselective manner. Full article

(This article belongs to the Special Issue Catalytic Asymmetric Synthesis)

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218 KiB

Open AccessArticle
Effects of Acute Gamma Irradiation on Physiological Traits and Flavonoid Accumulation of Centella asiatica
by Sina Siavash Moghaddam, Hawa Jaafar, Rusli Ibrahim, Asmah Rahmat, Maheran Abdul Aziz and Elizabeth Philip

Molecules 2011, 16(6), 4994-5007; https://doi.org/10.3390/molecules16064994 - 17 Jun 2011
Cited by 69 | Viewed by 9212
Abstract
In the present study, two accessions of Centella asiatica (CA03 and CA23) were subjected to gamma radiation to examine the response of these accessions in terms of survival rate, flavonoid contents, leaf gas exchange and leaf mass. Radiation Sensitivity Tests revealed that based [...] Read more.

In the present study, two accessions of Centella asiatica (CA03 and CA23) were subjected to gamma radiation to examine the response of these accessions in terms of survival rate, flavonoid contents, leaf gas exchange and leaf mass. Radiation Sensitivity Tests revealed that based on the survival rate, the LD₅₀ (gamma doses that killed 50% of the plantlets) of the plantlets were achieved at 60 Gy for CA03 and 40 Gy for CA23. The nodal segments were irradiated with gamma rays at does of 30 and 40 Gy for Centella asiatica accession ‘CA03’ and 20 and 30 Gy for accession ‘CA23. The nodal segment response to the radiation was evaluated by recording the flavonoid content, leaf gas exchange and leaf biomass. The experiment was designed as RCBD with five replications. Results demonstrated that the irradiated plantlets exhibited greater total flavonoid contents (in eight weeks) significantly than the control where the control also exhibited the highest total flavonoid contents in the sixth week of growth; 2.64 ± 0.02 mg/g DW in CA03 and 8.94 ± 0.04 mg/g DW in CA23. The total flavonoid content was found to be highest after eight weeks of growth, and this, accordingly, stands as the best time for leaf harvest. Biochemical differentiation based on total flavonoid content revealed that irradiated plantlets in CA23 at 20 and 30 Gy after eight weeks contained the highest total flavonoid concentrations (16.827 ± 0.02; 16.837 ± 0.008 mg/g DW, respectively) whereas in CA03 exposed to 30 and 40 Gy was found to have the lowest total flavonid content (5.83 ± 0.11; 5.75 ± 0.03 mg/g DW). Based on the results gathered in this study, significant differences were found between irradiated accessions and control ones in relation to the leaf gas. The highest PN and gs were detected in CA23 as control followed by CA23 irradiated to 20Gy (CA23G20) and CA23G30 and the lowest PN and gs were observed in CA03 irradiated to 40Gy (CA03G40). Moreover, there were no significant differences in terms of PN and gs among the irradiated plants in each accession. The WUE of both irradiated accessions of Centella asiatica were reduced as compared with the control plants (p < 0.01) while Ci and E were enhanced. There were no significant differences in the gas exchange parameters among radiated plants in each accession. Moreover, malondialdehyde (MDA) of accessions after gamma treatments were significantly higher than the control, however, flavonoids which were higher concentration in irradiated plants can scavenge surplus free radicals. Therefore, the findings of this study have proven an efficient method of in vitro mutagenesis through gamma radiation based on the pharmaceutical demand to create economically superior mutants of C. asiatica. In other words, the results of this study suggest that gamma irradiation on C. asiatica can produce mutants of agricultural and economical importance. Full article

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279 KiB

Open AccessArticle
Epitope Prediction Based on Random Peptide Library Screening: Benchmark Dataset and Prediction Tools Evaluation
by Pingping Sun, Wenhan Chen, Yanxin Huang, Hongyan Wang, Zhiqiang Ma and Yinghua Lv

Molecules 2011, 16(6), 4971-4993; https://doi.org/10.3390/molecules16064971 - 16 Jun 2011
Cited by 20 | Viewed by 8825
Abstract
Epitope prediction based on random peptide library screening has become a focus as a promising method in immunoinformatics research. Some novel software and web-based servers have been proposed in recent years and have succeeded in given test cases. However, since the number of [...] Read more.

Epitope prediction based on random peptide library screening has become a focus as a promising method in immunoinformatics research. Some novel software and web-based servers have been proposed in recent years and have succeeded in given test cases. However, since the number of available mimotopes with the relevant structure of template-target complex is limited, a systematic evaluation of these methods is still absent. In this study, a new benchmark dataset was defined. Using this benchmark dataset and a representative dataset, five examples of the most popular epitope prediction software products which are based on random peptide library screening have been evaluated. Using the benchmark dataset, in no method did performance exceed a 0.42 precision and 0.37 sensitivity, and the MCC scores suggest that the epitope prediction results of these software programs are greater than random prediction about 0.09–0.13; while using the representative dataset, most of the values of these performance measures are slightly improved, but the overall performance is still not satisfactory. Many test cases in the benchmark dataset cannot be applied to these pieces of software due to software limitations. Moreover chances are that these software products are overfitted to the small dataset and will fail in other cases. Therefore finding the correlation between mimotopes and genuine epitope residues is still far from resolved and much larger dataset for mimotope-based epitope prediction is desirable. Full article

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2005 KiB

Open AccessArticle
Anti-Migration Effects of Gekko Sulfated Glycopeptide on Human Hepatoma SMMC-7721 Cells
by Xiong-Zhi Wu, Dan Chen and Xiao-Qiang Han

Molecules 2011, 16(6), 4958-4970; https://doi.org/10.3390/molecules16064958 - 16 Jun 2011
Cited by 20 | Viewed by 8023
Abstract
Gekko swinhonis Guenther has been used as an anti-cancer drug in traditional Chinese medicine for hundreds of years. Previous studies showed that the Gekko sulfated polysaccharide-protein complex suppressed the proliferation and migration of hepatoma cells. Gekko sulfated glycopeptide α was obtained from Gekko [...] Read more.

Gekko swinhonis Guenther has been used as an anti-cancer drug in traditional Chinese medicine for hundreds of years. Previous studies showed that the Gekko sulfated polysaccharide-protein complex suppressed the proliferation and migration of hepatoma cells. Gekko sulfated glycopeptide α was obtained from Gekko sulfated polysaccharide-protein complex using papain hydrolysis. Gekko sulfated glycopeptide α inhibited the proliferation and migration of SMMC-7721 cells. The secretion of IL-8 and the concentration of intracellular calcium were decreased after Gekko sulfated glycopeptide α exposure. SMMC-7721 cells in the control group showed abnormal features, with a polygonal shape, whereas this changed to a spindle shape after the treatment with Gekko sulfated glycopeptide α. Actin ﬁlaments were distributed diffusely along the cell membrane in control cells, whereas those were polymerized and preferentially accumulated in the cytoplasm of treated cells. Microtubules distributed in the cytoplasm of untreated cells were located diffusely whereas those in treated cells were polymerized. Therefore, Gekko sulfated glycopeptide α inhibit the migration of hepatoma cells via reducing the secretion of IL-8 and the concentration of intracellular calcium, as well as regulating the reorganization of cytoskeleton. Full article

(This article belongs to the Section Natural Products Chemistry)

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298 KiB

Open AccessArticle
Microwave Assisted Synthesis of Some New Fused 1,2,4-Triazines Bearing Thiophene Moieties With Expected Pharmacological Activity
by Hosam A. Saad, Mohamed M. Youssef and Mosselhi A. Mosselhi

Molecules 2011, 16(6), 4937-4957; https://doi.org/10.3390/molecules16064937 - 15 Jun 2011
Cited by 71 | Viewed by 7992
Abstract
Rapid and efficient solvent-free synthesis of 4-amino-3-mercapto-6-[2-(2-thienyl)vinyl]-1,2,4-triazin-5(4H)-one 1 under microwave irradiation is described. Some new fused heterobicyclic nitrogen systems such as 1,2,4-triazino[3,4-b][1,3,4]thiadiazinones, 1,3,4-thiadiazolo[2,3-c][1,2,4]triazinone and pyrazolo[5,1-c]-[1,2,4]triazine-7-carbonitrile, have been synthesized by treatment of 1 with bifunctional oxygen [...] Read more.

Rapid and efficient solvent-free synthesis of 4-amino-3-mercapto-6-[2-(2-thienyl)vinyl]-1,2,4-triazin-5(4H)-one 1 under microwave irradiation is described. Some new fused heterobicyclic nitrogen systems such as 1,2,4-triazino[3,4-b][1,3,4]thiadiazinones, 1,3,4-thiadiazolo[2,3-c][1,2,4]triazinone and pyrazolo[5,1-c]-[1,2,4]triazine-7-carbonitrile, have been synthesized by treatment of 1 with bifunctional oxygen and halogen compounds, CS₂/KOH and malononitrile via heterocyclization reactions, in addition to some uncondensed triazines. Structures of the products have been deduced from their elemental analysis and spectral data (IR, ¹H-NMR, ¹³C-NMR). Select new synthesized compounds were screened as anticancer agents, with some showing activity as cytotoxic agents against different cancer cell lines. Full article

(This article belongs to the Special Issue Microwave Assisted Synthesis)

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177 KiB

Open AccessArticle
Derivatives of 10,16-Dihydroxyhexadecanoic Acid Isolated from Tomato (Solanum lycopersicum) as Potential Material for Aliphatic Polyesters
by Daniel Arrieta-Baez, Miguel Cruz-Carrillo, Mayra Beatriz Gómez-Patiño and L. Gerardo Zepeda-Vallejo

Molecules 2011, 16(6), 4923-4936; https://doi.org/10.3390/molecules16064923 - 15 Jun 2011
Cited by 22 | Viewed by 9365
Abstract
The main monomer of tomato cuticle, 10,16-dihydroxyhexadecanoic acid (or 10,16-dihydroxypalmitic acid; 10,16-DHPA), was isolated and used to efficiently synthesize two different monomers (16-hydroxy-10-oxo-hexadecanoic and 7-oxohexa-decanedioic acids) in addition to a dimer and linear and branched trimers. These compounds were fully characterized using NMR [...] Read more.

The main monomer of tomato cuticle, 10,16-dihydroxyhexadecanoic acid (or 10,16-dihydroxypalmitic acid; 10,16-DHPA), was isolated and used to efficiently synthesize two different monomers (16-hydroxy-10-oxo-hexadecanoic and 7-oxohexa-decanedioic acids) in addition to a dimer and linear and branched trimers. These compounds were fully characterized using NMR and MS techniques and could be used as starting materials for the synthesis of a wide range of chemicals and bio-polyesters, particularly the latter due to their physical properties, non-toxicity, and relative abundance among raw materials. Full article

(This article belongs to the Section Molecular Diversity)

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2447 KiB

Open AccessCommunication
Directed Formation of DNA Nanoarrays through Orthogonal Self-Assembly
by Jonathan R. Burns, Jurgita Zekonyte, Giuliano Siligardi, Rohanah Hussain and Eugen Stulz

Molecules 2011, 16(6), 4912-4922; https://doi.org/10.3390/molecules16064912 - 15 Jun 2011
Cited by 14 | Viewed by 6801
Abstract
We describe the synthesis of terpyridine modified DNA strands which selectively form DNA nanotubes through orthogonal hydrogen bonding and metal complexation interactions. The short DNA strands are designed to self-assemble into long duplexes through a sticky-end approach. Addition of weakly binding metals such [...] Read more.

We describe the synthesis of terpyridine modified DNA strands which selectively form DNA nanotubes through orthogonal hydrogen bonding and metal complexation interactions. The short DNA strands are designed to self-assemble into long duplexes through a sticky-end approach. Addition of weakly binding metals such as Zn(II) and Ni(II) induces the formation of tubular arrays consisting of DNA bundles which are 50-200 nm wide and 2-50 nm high. TEM shows additional long distance ordering of the terpy-DNA complexes into fibers. Full article

(This article belongs to the Special Issue Nucleoside Analogues)

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237 KiB

Open AccessArticle
Synthesis and In Vitro Protein Tyrosine Kinase Inhibitory Activity of Furan-2-yl(phenyl)methanone Derivatives
by Fei Lang Zheng, Shu Rong Ban, Xiu E Feng, Cheng Xiao Zhao, Wenhan Lin and Qing Shan Li

Molecules 2011, 16(6), 4897-4911; https://doi.org/10.3390/molecules16064897 - 14 Jun 2011
Cited by 13 | Viewed by 7615
Abstract
A series of novel furan-2-yl(phenyl)methanone derivatives were synthesized, and their structures were established on the basis of ¹H-NMR, ¹³C-NMR and mass spectral data. All the prepared compounds were screened for their in vitro protein tyrosine kinase inhibitory activity and several new [...] Read more.

A series of novel furan-2-yl(phenyl)methanone derivatives were synthesized, and their structures were established on the basis of ¹H-NMR, ¹³C-NMR and mass spectral data. All the prepared compounds were screened for their in vitro protein tyrosine kinase inhibitory activity and several new derivatives exhibited promising activity, which, in some cases, was identical to, or even better than that of genistein, a positive reference compound. The preliminary structure-activity relationships of these compounds were investigated and are discussed. Full article

(This article belongs to the Section Medicinal Chemistry)

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252 KiB

Open AccessArticle
Comparison of Compositions and Antimicrobial Activities of Essential Oils from Chemically Stimulated Agarwood, Wild Agarwood and Healthy Aquilaria sinensis (Lour.) Gilg Trees
by Huaiqiong Chen, Yun Yang, Jian Xue, Jianhe Wei, Zheng Zhang and Hongjiang Chen

Molecules 2011, 16(6), 4884-4896; https://doi.org/10.3390/molecules16064884 - 14 Jun 2011
Cited by 163 | Viewed by 12705
Abstract
The composition and antimicrobial activity of the essential oils which were obtained from agarwood originated from Aquilaria sinensis (Lour.) Gilg stimulated by the chemical method (S1) were characterized, taking wild agarwood (S2) and healthy trees (S3) respectively as the positive and negative controls. [...] Read more.

The composition and antimicrobial activity of the essential oils which were obtained from agarwood originated from Aquilaria sinensis (Lour.) Gilg stimulated by the chemical method (S1) were characterized, taking wild agarwood (S2) and healthy trees (S3) respectively as the positive and negative controls. The chemical composition of S1 was investigated by gas chromatography-mass spectrometry (GC-MS). The essential oil of S1 showed a similar composition to that of S2, being rich in sesquiterpenes and aromatic constituents. However, the essential oil of S3 was abundant in fatty acids and alkanes. Essential oils of S1 and S2 had better inhibition activities towards Bacillus subtilis and Staphyloccus aureus, compared with essential oil of S3. Escherichia coli was not sensitive to any of them. Full article

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