Molecules

192 KiB

Open AccessArticle

New Conjugated Benzothiazole-N-oxides: Synthesis and Biological Activity

by Peter Gajdoš, Peter Magdolen, Pavol Zahradník and Pavlína Foltínová

Molecules 2009, 14(12), 5382-5388; https://doi.org/10.3390/molecules14125382 - 23 Dec 2009

Cited by 14 | Viewed by 9459

Eleven new 2-styrylbenzothiazole-N-oxides have been prepared by aldol – type condensation reactions between 2-methylbenzothiazole–N-oxide and para-substituted benzaldehydes. Compounds with cyclic amino substituents showed typical push-pull molecule properties. Four compounds were tested against various bacterial strains as well as [...] Read more.

Eleven new 2-styrylbenzothiazole-N-oxides have been prepared by aldol – type condensation reactions between 2-methylbenzothiazole–N-oxide and para-substituted benzaldehydes. Compounds with cyclic amino substituents showed typical push-pull molecule properties. Four compounds were tested against various bacterial strains as well as the protozoan Euglena gracilis as model microorganisms. Unlike previously prepared analogous benzothiazolium salts, only weak activity was recorded. Full article

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322 KiB

Open AccessReview

Role of Phosphatidyl-Serine in Bone Repair and Its Technological Exploitation

by Antonio Merolli and Matteo Santin

Molecules 2009, 14(12), 5367-5381; https://doi.org/10.3390/molecules14125367 - 22 Dec 2009

Cited by 44 | Viewed by 11955

Abstract

In the 1970s, morphological evidence collected by electron microscopy linked mineral deposition (“calcification” or “mineralization”) in newly-forming bone to membrane-encapsulated particles of a diameter of approximately 100 nm (50–200 nm) that were called “matrix vesiscles”. As the characterisation of these vesicles progressed towards [...] Read more.

In the 1970s, morphological evidence collected by electron microscopy linked mineral deposition (“calcification” or “mineralization”) in newly-forming bone to membrane-encapsulated particles of a diameter of approximately 100 nm (50–200 nm) that were called “matrix vesiscles”. As the characterisation of these vesicles progressed towards their biochemical composition, the role of lipids in the biomineralization process appeared to be crucial. In particular, a group of cell-membrane phospholipids were identified as major players in the crystal formation process. Indeed, in the 1980s it became clear that phosphatidylserine, together with proteins of the annexin family, was among the most important molecules in binding calcium ions and that this phospholipid was involved in the regulation of the early stages of mineralization in vivo. During the same period of time, the number of surgical implantations of orthopaedic, dental and maxilo-facial devices requiring full integration with the treated bone prompted the study of new functionalisation molecules able to establish a stable bonding with the mineral phase of the host tissue. In the late 1990s studies started that aimed at exploiting the potential of calcium-binding phospholipids and, in particular, of the phosphatidylserine as functionalisation molecules to improve the osteointegration of artificial implants. Later, papers have been published that show the potential of the phophatidylserine and phosphatidylserine-mimicking coating technology to promote calcification both in vitro and in vivo. The promising results support the future clinical application of these novel osteointegrative biomaterials. Full article

(This article belongs to the Special Issue Phospholipids)

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110 KiB

Open AccessEditorial

Discovery of Artemisinin (Qinghaosu)

by Fulong Liao

Molecules 2009, 14(12), 5362-5366; https://doi.org/10.3390/molecules14125362 - 21 Dec 2009

Cited by 47 | Viewed by 18409

Abstract

Artemisinin (Qinghaosu), a new antimalarial drug, was discovered in China in the early 1970s. The discovery of artemisinin is attributed to You-You Tu, at that time a middle-aged phytochemist working in the Institute of Chinese Materia Medica, China Academy of Traditional Chinese Medicine. [...] Read more.

Artemisinin (Qinghaosu), a new antimalarial drug, was discovered in China in the early 1970s. The discovery of artemisinin is attributed to You-You Tu, at that time a middle-aged phytochemist working in the Institute of Chinese Materia Medica, China Academy of Traditional Chinese Medicine. The following paragraph provides a brief summary of her discovery. [...] Full article

(This article belongs to the Special Issue Artemisinin (Qinghaosu): Commemorative Issue in Honor of Professor Youyou Tu on the Occasion of her 80th Anniversary)

488 KiB

Open AccessArticle

Correlation between Antioxidant Activities and Phenolic Contents of Radix Angelicae Sinensis (Danggui)

by Xican Li, Xiaoting Wu and Ling Huang

Molecules 2009, 14(12), 5349-5361; https://doi.org/10.3390/molecules14125349 - 21 Dec 2009

Cited by 206 | Viewed by 16550

Abstract

Radix Angelicae Sinensisis (RAS) is one of the most popular traditional Chinese herbal medicines. In the present study, six RAS extracts (i.e., phenolic extract PE, petroleum ether extract PEE, ethyl acetate extract EAE, absolute ethanol extract AEE, 95% ethanol extract 95 [...] Read more.

Radix Angelicae Sinensisis (RAS) is one of the most popular traditional Chinese herbal medicines. In the present study, six RAS extracts (i.e., phenolic extract PE, petroleum ether extract PEE, ethyl acetate extract EAE, absolute ethanol extract AEE, 95% ethanol extract 95 EE, and water extract WE) were prepared and their antioxidant activities measured by DPPH (1,1-diphenyl-2-picrylhydrazyl radical), ABTS [2,2′-azino-bis(3- ethylbenzothiazoline-6-sulfonic acid diammonium salt)], Reducing power, •O^2– and lipid peroxidation assays. In general, PE, PEE and EAE had relatively high antioxidant activity, followed by AEE with moderate activity, as compared with 95 EE and WE that had low activity. Their phenolic contents (including total phenolic, ferulic acid, caffeic acid, same as below) were then determined by HPLC or spectrophotometry. The sequence of phenolic contents was roughly identical with that of antioxidant activity. When the values of 1/IC₅₀ of various antioxidant assays were used to evaluate the level of antioxidant of the RAS extracts, (plot between 1/IC₅₀ values and phenolic contents), the correlation coefficient (R) ranged from 0.642 to 0.941, with an average value of 0.839. Significant positive correlations demonstrated that the antioxidant effects of RAS might generally be considered a result of the presence of the phenolic compounds, especially ferulic acid and caffeic acid. Full article

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498 KiB

Open AccessArticle

Synthesis and Biological Evaluation of Novel 1-Alkyltryptophan Analogs as Potential Antitumor Agents

by Ting Sun, Zhao-Long Li, Hua Tian, Shih-Chen Wang and Jiong Cai

Molecules 2009, 14(12), 5339-5348; https://doi.org/10.3390/molecules14125339 - 18 Dec 2009

Cited by 8 | Viewed by 10278

Abstract

To seek novel antitumor agents, we designed and synthesized new 1-tryptophan analogs based on tryptophan catabolism. 1-Alkyltryptophan analogues including 1-ethyltryptophan (1-ET), 1-propyltryptophan (1-PT), 1-isopropyltryptophan (1-isoPT) and 1-butyltryptophan (1-BT) were synthesized from tryptophan. We examined whether those compounds had the antiproliferative effects on SGC7901 [...] Read more.

To seek novel antitumor agents, we designed and synthesized new 1-tryptophan analogs based on tryptophan catabolism. 1-Alkyltryptophan analogues including 1-ethyltryptophan (1-ET), 1-propyltryptophan (1-PT), 1-isopropyltryptophan (1-isoPT) and 1-butyltryptophan (1-BT) were synthesized from tryptophan. We examined whether those compounds had the antiproliferative effects on SGC7901 and HeLa cells line by using MTT assay in vitro, respectively. Compared to tryptophan, all targeted compounds efficiently inhibited proliferation of two cancer cell lines at 2 mmol/L for 48 hours. Among these tryptophan analogs, 1-BT showed the most powerful cytotoxicity against SGC7901 and HeLa cells at 1 mmol/L and 2 mmol/L concentration. These data suggest that some specific tryptophan analogs could be developed as potential anti-neoplastic agents. Full article

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424 KiB

Open AccessArticle

Cytotoxic Activity of Curcumin towards CCRF-CEM Leukemia Cells and Its Effect on DNA Damage

by Yu Kong, Wei Ma, Xia Liu, Yuangang Zu, Yujie Fu, Nan Wu, Lu Liang, Liping Yao and Thomas Efferth

Molecules 2009, 14(12), 5328-5338; https://doi.org/10.3390/molecules14125328 - 17 Dec 2009

Cited by 39 | Viewed by 14930

Abstract

The cytotoxic activity of curcumin towards CCRF-CEM human T-cell leukemia cells was measured by the MTT assay. Tumor cells were more sensitive to the cytotoxic activity of curcumin or curcumin-Cu (II)compared to normal cells, and the IC₅₀ ofcurcumin towards CCRF-CEM cells was [...] Read more.

The cytotoxic activity of curcumin towards CCRF-CEM human T-cell leukemia cells was measured by the MTT assay. Tumor cells were more sensitive to the cytotoxic activity of curcumin or curcumin-Cu (II)compared to normal cells, and the IC₅₀ ofcurcumin towards CCRF-CEM cells was 8.68 µM, and that ofcurcumin-Cu (II) was 8.14 µM. The cell cycle distribution of curcumin-treated CCRF-CEM cells was analyzed by flow cytometry. DNA damage induced by oxidants such as curcumin-Cu (II) ions is considered as one of the main causes of cell inactivation. Therefore, we analyzed the effect of curcumin on DNA damage by agarose gel electrophoresis and atomic force microscopy (AFM). Gel electrophoresis analyses showed that curcumin or Cu (II) alone failed to cause DNA damage in pBR322 plasmid DNA as compared with the normal plasmid. However, DNA plasmids were mostly damaged after treatment with curcumin of different concentrations in the presence of Cu (II). Two forms were observed by means of AFM: closed circular plasmids and linear plasmids. DNA damage induced by a combination of curcumin and Cu (II) was also found by agarose gel electrophoresis, which was applied as control method to verify the results obtained by AFM. Full article

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150 KiB

Open AccessArticle

A Chalcone Glycoside from the Fruits of Sorbus commixta Hedl.

by Lok Ranjan Bhatt, Moon Sung Bae, Bo Mi Kim, Gi-Su Oh and Kyu Yun Chai

Molecules 2009, 14(12), 5323-5327; https://doi.org/10.3390/molecules14125323 - 16 Dec 2009

Cited by 22 | Viewed by 11670

Abstract

Sorbus commixta Hedl. (Rosaceae) has been traditionally used in oriental countries for the treatment of asthma and other bronchial disorders. In this study, a chalcone glycoside was isolated from the ethyl acetate extract of the fruits of this plant. The compound was identified [...] Read more.

Sorbus commixta Hedl. (Rosaceae) has been traditionally used in oriental countries for the treatment of asthma and other bronchial disorders. In this study, a chalcone glycoside was isolated from the ethyl acetate extract of the fruits of this plant. The compound was identified as neosakuranin based on the spectroscopic analysis and comparion with literature data. This is the first report of isolation of neosakuranin from Sorbus commixta. Full article

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Graphical abstract

358 KiB

Open AccessReview

Molecular Iodine—An Expedient Reagent for Oxidative Aromatization Reactions of α,β-Unsaturated Cyclic Compounds

by Malose Jack Mphahlele

Molecules 2009, 14(12), 5308-5322; https://doi.org/10.3390/molecules14125308 - 16 Dec 2009

Cited by 60 | Viewed by 15518

Abstract

Prompted by the scant attention paid by published literature reviews to the applications of molecular iodine in oxidative aromatization reactions, we decided to review methods developed to-date involving iodine as an oxidant to promote aromatization of α,β-unsaturated cyclic compounds. Full article

(This article belongs to the Special Issue Organic Iodine Chemistry)

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197 KiB

Open AccessArticle

Protecting-Group-Free Synthesis of 2-Deoxy-Aza-Sugars

by Emma Marie Dangerfield, Catherine Heather Plunkett, Bridget Louise Stocker and Mattie Simon Maria Timmer

Molecules 2009, 14(12), 5298-5307; https://doi.org/10.3390/molecules14125298 - 16 Dec 2009

Cited by 26 | Viewed by 13355

Abstract

The protecting-group-free asymmetric synthesis of 1,2,4-trideoxy-1,4-imino-L-xylitol is readily achieved in five steps from 2-deoxy-D-ribose and with an overall yield of 48%. Key in this synthesis is the application of our recently developed Vasella-reductive amination and carbamate annulation methodologies to the synthesis of 2-deoxy-aza-sugars. [...] Read more.

The protecting-group-free asymmetric synthesis of 1,2,4-trideoxy-1,4-imino-L-xylitol is readily achieved in five steps from 2-deoxy-D-ribose and with an overall yield of 48%. Key in this synthesis is the application of our recently developed Vasella-reductive amination and carbamate annulation methodologies to the synthesis of 2-deoxy-aza-sugars. The carbamate annulation occurred with excellent yield and diastereoselectively (>20:1 d.r.), in favour of the 3,4-cis isomer. Full article

(This article belongs to the Special Issue Asymmetric Synthesis)

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123 KiB

Open AccessArticle

Germacrene D, A Common Sesquiterpene in the Genus Bursera (Burseraceae)

by Koji Noge and Judith X. Becerra

Molecules 2009, 14(12), 5289-5297; https://doi.org/10.3390/molecules14125289 - 15 Dec 2009

Cited by 51 | Viewed by 12237

Abstract

The volatile components of the leaves of five Bursera species, B. copallifera, B. exselsa, B. mirandae, B. ruticola and B. fagaroides var. purpusii were determined by gas chromatography–mass spectrometry (GC–MS). Germacrene D was one of the predominant components (15.1–56.2%) of [...] Read more.

The volatile components of the leaves of five Bursera species, B. copallifera, B. exselsa, B. mirandae, B. ruticola and B. fagaroides var. purpusii were determined by gas chromatography–mass spectrometry (GC–MS). Germacrene D was one of the predominant components (15.1–56.2%) of all of these species. Germacrene D has also been found in other Bursera species and some species of Commiphora, the sister group of Bursera, suggesting that the production of germacrene D might be an ancient trait in the genus Bursera. Full article

209 KiB

Open AccessArticle

Chemical Constituents from the Stems of Diospyros maritima

by Chi-I Chang, Chiy-Rong Chen, Hsi-Lin Chiu, Chao-Lin Kuo and Yueh-Hsiung Kuo

Molecules 2009, 14(12), 5281-5288; https://doi.org/10.3390/molecules14125281 - 15 Dec 2009

Cited by 7 | Viewed by 9742

Abstract

A new phenolic, bis(6-hydroxy-2,3,4-trimethoxylphen-1-yl)methane (1) and a new butanedioate, butylmethyl succinate (2), along with twenty-nine known compounds including one naphthoquinone derivative, two chromanones, eight benzenoids, one lignan, one tocopherol, and sixteen triterpenoids were isolated from the stems of Diospyros [...] Read more.

A new phenolic, bis(6-hydroxy-2,3,4-trimethoxylphen-1-yl)methane (1) and a new butanedioate, butylmethyl succinate (2), along with twenty-nine known compounds including one naphthoquinone derivative, two chromanones, eight benzenoids, one lignan, one tocopherol, and sixteen triterpenoids were isolated from the stems of Diospyros maritima. epi-Isoshinanolone (3) was isolated in pure form for the first time. In addition, 5,7-dihydroxy-2-methylchomanone (4) was isolated from a natural source for the first time. Their structures were established on the basis of spectroscopic data as well as direct comparison with authentic samples. Full article

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394 KiB

Open AccessArticle

1-Arylsulfonyl-2-(Pyridylmethylsulfinyl) Benzimidazoles as New Proton Pump Inhibitor Prodrugs

by Jai Moo Shin, George Sachs, Young-moon Cho and Michael Garst

Molecules 2009, 14(12), 5247-5280; https://doi.org/10.3390/molecules14125247 - 15 Dec 2009

Cited by 13 | Viewed by 10174

Abstract

New arylsulfonyl proton pump inhibitor (PPI) prodrug forms were synthesized. These prodrugs provided longer residence time of an effective PPI plasma concentration, resulting in better gastric acid inhibition. Full article

(This article belongs to the Special Issue Prodrugs)

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331 KiB

Open AccessCommunication

MALDI-TOF MS Profiling of Annonaceous Acetogenins in Annona muricata Products for Human Consumption

by Pierre Champy, Vincent Guérineau and Olivier Laprévote

Molecules 2009, 14(12), 5235-5246; https://doi.org/10.3390/molecules14125235 - 15 Dec 2009

Cited by 43 | Viewed by 12786

Abstract

Annonaceous acetogenins are proposed as environmental neurotoxicants consumed through medicinal and alimentary habits and responsible for atypical parkinsonian syndromes observed in tropical areas. Potential sources of exposure still have to be determined, as, to date, only a few batches of products for human [...] Read more.

Annonaceous acetogenins are proposed as environmental neurotoxicants consumed through medicinal and alimentary habits and responsible for atypical parkinsonian syndromes observed in tropical areas. Potential sources of exposure still have to be determined, as, to date, only a few batches of products for human consumption were searched for these compounds. To assess the presence of acetogenins, we propose a fast, sensitive and accurate method of screening, using MALDI-TOF MS, with minimal sample preparation. Development of the technique is discussed. Its application to leaves of herbal tea, pulp and bottled nectar of Annona muricata is presented. Full article

(This article belongs to the Special Issue Acetogenins: Extraction, Synthesis and Biological Properties)

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176 KiB

Open AccessArticle

Generation of 500-Member Library of 10-Alkyl-2-R¹,3-R²-4,10-Dihydrobenzo[4,5]imidazo[1,2-α]pyrimidin-4-ones

by Svetlana M. Sirko, Nikolay Yu. Gorobets, Vladimir I. Musatov and Sergey M. Desenko

Molecules 2009, 14(12), 5223-5234; https://doi.org/10.3390/molecules14125223 - 15 Dec 2009

Cited by 9 | Viewed by 9416

Abstract

Representative benzimidazopyrimidinones were previously reported to be intercalating antitumor agents. In this work, we used 2-substituted 4,10-dihydrobenzo [4,5]imidazo[1,2-α]pyriminin-4-ones for their diversification by regioselective alkylation. Under the conditions established, the alkylation gave 10-alkyl derivatives which permitted the parallel generation of a 500-member [...] Read more.

Representative benzimidazopyrimidinones were previously reported to be intercalating antitumor agents. In this work, we used 2-substituted 4,10-dihydrobenzo [4,5]imidazo[1,2-α]pyriminin-4-ones for their diversification by regioselective alkylation. Under the conditions established, the alkylation gave 10-alkyl derivatives which permitted the parallel generation of a 500-member library of the title compounds. Full article

(This article belongs to the Special Issue Molecular Diversity Feature Papers)

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236 KiB

Open AccessArticle

A Striking Exception to the Chelate Model for Acyclic Diastereocontrol: Efficient Access to a Versatile Propargyl Alcohol for Chemical Synthesis

by Sami F. Tlais, Ronald J. Clark and Gregory B. Dudley

Molecules 2009, 14(12), 5216-5222; https://doi.org/10.3390/molecules14125216 - 15 Dec 2009

Cited by 5 | Viewed by 10531

Abstract

The four-step, asymmetric synthesis of a chiral propargyl alcohol 1 from (R)-pantolactone is described. A key feature of the synthesis is a diastereoselective acetylide addition to a chiral α-alkoxy-aldehyde 7, in which unusual Felkin selectivity is observed, despite the potential [...] Read more.

The four-step, asymmetric synthesis of a chiral propargyl alcohol 1 from (R)-pantolactone is described. A key feature of the synthesis is a diastereoselective acetylide addition to a chiral α-alkoxy-aldehyde 7, in which unusual Felkin selectivity is observed, despite the potential for chelation control. Crystalline propargyl alcohol 1 is valuable for complex molecule synthesis, and is easy to prepare in multi-gram quantities and high diastereomeric purity. Full article

(This article belongs to the Special Issue Asymmetric Synthesis)

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264 KiB

Open AccessArticle

Synthesis and Antimicrobial Activity of Some Pyridinium Salts

by Vildan Alptüzün, Sülünay Parlar, Hüseyin Taşlı and Ercin Erciyas

Molecules 2009, 14(12), 5203-5215; https://doi.org/10.3390/molecules14125203 - 14 Dec 2009

Cited by 46 | Viewed by 9544

Abstract

Some substituted benzylidenehydrazinylpyridinium derivatives bearing benzyl, ethylphenyl and propylphenyl groups on the pyridinium nitrogen were synthesized and screened for possible antibacterial and antifungal activities against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans using the microdilution method. Antimicrobial test results [...] Read more.

Some substituted benzylidenehydrazinylpyridinium derivatives bearing benzyl, ethylphenyl and propylphenyl groups on the pyridinium nitrogen were synthesized and screened for possible antibacterial and antifungal activities against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans using the microdilution method. Antimicrobial test results indicated that compounds containing a 3-phenylpropyl chain displayed the highest antimicrobial activity against Staphylococcus aureus and the compound 3d was the most active in the series against all tested bacteria and fungi strains. Full article

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427 KiB

Open AccessArticle

Synthesis and Evaluation of in Vitro Biological Activity of 4-Substituted Arylpiperazine Derivatives of 1,7,8,9-Tetrachloro-10,10-dimethoxy-4-azatricyclo[5.2.1.0^2,6]dec-8-ene-3,5-dione

by Jerzy Kossakowski, Magdalena Pakosinska-Parys, Marta Struga, Izabela Dybala, Anna E. Koziol, Paolo La Colla, Laura Ester Marongiu, Cristina Ibba, David Collu and Roberta Loddo

Molecules 2009, 14(12), 5189-5202; https://doi.org/10.3390/molecules14125189 - 11 Dec 2009

Cited by 17 | Viewed by 12865

Abstract

A series of twenty arylpiperazine derivatives of 1,7,8,9-tetrachloro-10,10-dimethoxy-4-azatricyclo[5.2.1.0^2,6]dec-8-ene-3,5-dione have been prepared. These derivatives were tested in vitro with the aim of identifying novel lead compounds active against emergent and re-emergent human and cattle infectious diseases (AIDS, hepatitis B and C, tuberculosis, [...] Read more.

A series of twenty arylpiperazine derivatives of 1,7,8,9-tetrachloro-10,10-dimethoxy-4-azatricyclo[5.2.1.0^2,6]dec-8-ene-3,5-dione have been prepared. These derivatives were tested in vitro with the aim of identifying novel lead compounds active against emergent and re-emergent human and cattle infectious diseases (AIDS, hepatitis B and C, tuberculosis, bovine viral diarrhea). In particular, these compounds were evaluated in vitro against representatives of different virus classes, such as a HIV-1 (Retrovirus), a HBV (Hepadnavirus) and the single-stranded RNA⁺ viruses Yellow fever virus (YFV) and Bovine viral diarrhea virus (BVDV), both belonging to the Flaviridae. Compounds 2c, 2g and 3d showed a modest activity against CVB-2. The molecular structures of the starting imide 1 and one of propyl-piperazine derivatives, 3b, have been determined by an X-ray crystallography study. Full article

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Graphical abstract

377 KiB

Open AccessArticle

Pore Forming Properties of Cecropin-Melittin Hybrid Peptide in a Natural Membrane

by Alberto Milani, Mascia Benedusi, Marco Aquila and Giorgio Rispoli

Molecules 2009, 14(12), 5179-5188; https://doi.org/10.3390/molecules14125179 - 11 Dec 2009

Cited by 26 | Viewed by 10965

Abstract

The pore forming properties of synthetic cecropin-melittin hybrid peptide (Acetyl-KWKLFKKIGAVLKVL-CONH₂; CM15) were investigated by using photoreceptor rod outer segments (OS) isolated from frog retinae obtained by using the whole-cell configuration of the patch-clamp technique. CM15 was applied (and removed) to [...] Read more.

The pore forming properties of synthetic cecropin-melittin hybrid peptide (Acetyl-KWKLFKKIGAVLKVL-CONH₂; CM15) were investigated by using photoreceptor rod outer segments (OS) isolated from frog retinae obtained by using the whole-cell configuration of the patch-clamp technique. CM15 was applied (and removed) to (from) the OS in ~50 ms with a computer-controlled microperfusion system. Once the main OS endogenous conductance was blocked with light, the OS membrane resistance was ≥1 GΩ, allowing high resolution, low-noise recordings. Different to alamethicines, CM15 produced voltage-independent membrane permeabilisation, repetitive peptide application caused a progressive permeabilisation increase, and no single-channel events were detected at low peptide concentrations. Collectively, these results indicate a toroidal mechanism of pore formation by CM15. Full article

(This article belongs to the Special Issue Molecular Diversity Feature Papers)

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416 KiB

Open AccessCommunication

Highly Efficient and Reusable Copper-Catalyzed N-Arylation of Nitrogen-Containing Heterocycles with Aryl Halides

by A Young Kim, Hyun Ju Lee, Ji Chan Park, Hyunju Kang, Haesik Yang, Hyunjoon Song and Kang Hyun Park

Molecules 2009, 14(12), 5169-5178; https://doi.org/10.3390/molecules14125169 - 10 Dec 2009

Cited by 58 | Viewed by 11998

Abstract

CuO/AB was found to be a simple and efficient catalyst for the N-arylation of a variety of nitrogen-containing heterocycles, giving the products in excellent yields. Full article

(This article belongs to the Special Issue Advances in Heteroaromatic Chemistry)

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137 KiB

Open AccessArticle

A New 2-(2-Phenylethyl)Chromone from Chinese Eaglewood

by Hao-Fu Dai, Jun Liu, Yan-Bo Zeng, Zhuang Han, Hui Wang and Wen-Li Mei

Molecules 2009, 14(12), 5165-5168; https://doi.org/10.3390/molecules14125165 - 9 Dec 2009

Cited by 45 | Viewed by 12413

Abstract

A new 2-(2-phenylethyl)chromone, 5,6,7,8-tetrahydroxy-2-(3-hydroxy-4-methoxyphenethyl)-5,6,7,8-tetrahydro-4H-chromen-4-one (1) was isolated from the Chinese eaglewood [Aquilaria sinensis (Lour.) Gilg]. Its structure was established by detailed MS and NMR spectroscopic analysis, as well as comparison with literature data. Full article

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319 KiB

Open AccessReview

The Chemical Composition and Biological Properties of Coconut (Cocos nucifera L.) Water

by Jean W. H. Yong, Liya Ge, Yan Fei Ng and Swee Ngin Tan

Molecules 2009, 14(12), 5144-5164; https://doi.org/10.3390/molecules14125144 - 9 Dec 2009

Cited by 492 | Viewed by 102519

Abstract

Coconut water (coconut liquid endosperm), with its many applications, is one of the world’s most versatile natural product. This refreshing beverage is consumed worldwide as it is nutritious and beneficial for health. There is increasing scientific evidence that supports the role of coconut [...] Read more.

Coconut water (coconut liquid endosperm), with its many applications, is one of the world’s most versatile natural product. This refreshing beverage is consumed worldwide as it is nutritious and beneficial for health. There is increasing scientific evidence that supports the role of coconut water in health and medicinal applications. Coconut water is traditionally used as a growth supplement in plant tissue culture/micropropagation. The wide applications of coconut water can be justified by its unique chemical composition of sugars, vitamins, minerals, amino acids and phytohormones. This review attempts to summarise and evaluate the chemical composition and biological properties of coconut water. Full article

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

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Open AccessArticle

Synthesis of Chiral 1,4-Disubstituted-1,2,3-Triazole Derivatives from Amino Acids

by Michael Klein, Karin Krainz, Itedale Namro Redwan, Peter Dinér and Morten Grøtli

Molecules 2009, 14(12), 5124-5143; https://doi.org/10.3390/molecules14125124 - 9 Dec 2009

Cited by 14 | Viewed by 13365

Abstract

A versatile method for the synthesis of chiral 1,4-disubstituted-1,2,3-triazole derivatives starting from easily accessible naturally occurring D-or L-amino acids as chiral synthons is described. The amino acids were converted into azido alcohols, followed by copper catalyzed [3+2] cycloaddition reactions between the azido alcohols [...] Read more.

A versatile method for the synthesis of chiral 1,4-disubstituted-1,2,3-triazole derivatives starting from easily accessible naturally occurring D-or L-amino acids as chiral synthons is described. The amino acids were converted into azido alcohols, followed by copper catalyzed [3+2] cycloaddition reactions between the azido alcohols and methyl propiolate and subsequent ester aminolysis with primary and secondary amines furnished the target compounds, which were obtained in excellent yields with no racemization. Docking of selected target compounds shows that the chiral 1,4-disubstituted-1,2,3-triazoles derivatives has the potential of mimicking the binding mode of known purine analogues. Full article

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Open AccessArticle

Calpain Inhibition Reduces Axolemmal Leakage in Traumatic Axonal Injury

by Endre Czeiter, András Büki, Péter Bukovics, Orsolya Farkas, József Pál, Erzsébet Kövesdi, Tamás Dóczi and János Sándor

Molecules 2009, 14(12), 5115-5123; https://doi.org/10.3390/molecules14125115 - 9 Dec 2009

Cited by 14 | Viewed by 12250

Abstract

Calcium-induced, calpain-mediated proteolysis (CMSP) has recently been implicated to the pathogenesis of diffuse (traumatic) axonal injury (TAI). Some studies suggested that subaxolemmal CMSP may contribute to axolemmal permeability (AP) alterations observed in TAI. Seeking direct evidence for this premise we investigated whether subaxolemmal [...] Read more.

Calcium-induced, calpain-mediated proteolysis (CMSP) has recently been implicated to the pathogenesis of diffuse (traumatic) axonal injury (TAI). Some studies suggested that subaxolemmal CMSP may contribute to axolemmal permeability (AP) alterations observed in TAI. Seeking direct evidence for this premise we investigated whether subaxolemmal CMSP may contribute to axolemmal permeability alterations (APA) and pre-injury calpain-inhibition could reduce AP in a rat model of TAI. Horseradish peroxidase (HRP, a tracer that accumulates in axons with APA) was administered one hour prior to injury into the lateral ventricle; 30 min preinjury a single tail vein bolus injection of 30 mg/kg MDL-28170 (a calpain inhibitor) or its vehicle was applied in Wistar rats exposed to impact acceleration brain injury. Histological detection of traumatically injured axonal segments accumulating HRP and statistical analysis revealed that pre-injury administration of the calpain inhibitor MDL-28170 significantly reduced the average length of HRP-labeled axonal segments. The axono-protective effect of pre-injury calpain inhibition recently demonstrated with classical immunohistochemical markers of TAI was further corroborated in this experiment; significant reduction of the length of labeled axons in the drug-treated rats implicate CMSP in the progression of altered AP in TAI. Full article

(This article belongs to the Special Issue Neuroprotective Strategies)

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Open AccessArticle

Antimalarial Activity of Ultra-Short Peptides

by Lemuel Pérez-Picaso, Benjamín Velasco-Bejarano, A. Berenice Aguilar-Guadarrama, Rocío Argotte-Ramos and María Yolanda Rios

Molecules 2009, 14(12), 5103-5114; https://doi.org/10.3390/molecules14125103 - 8 Dec 2009

Cited by 15 | Viewed by 10216

Abstract

Ultra-short peptides 1-9 were designed and synthesized with phenylalanine, ornithine and proline amino acid residues and their effect on antimalarial activity was analyzed. On the basis of the IC₅₀ data for these compounds, the effects of nature, polarity, and amino acid sequence [...] Read more.

Ultra-short peptides 1-9 were designed and synthesized with phenylalanine, ornithine and proline amino acid residues and their effect on antimalarial activity was analyzed. On the basis of the IC₅₀ data for these compounds, the effects of nature, polarity, and amino acid sequence on Plasmodium berghei schizont cultures were analyzed too. Tetrapeptides Phe-Orn-Phe-Orn (4) and Lys-Phe-Phe-Orn (5) showed a very important activity with IC₅₀ values of 3.31 and 2.57 μM, respectively. These two tetrapeptides are candidates for subsequent in vivo assays and SARS investigations. Full article

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Open AccessReview

Neuroprotection by Radical Avoidance: Search for Suitable Agents

by Rüdiger Hardeland

Molecules 2009, 14(12), 5054-5102; https://doi.org/10.3390/molecules14125054 - 7 Dec 2009

Cited by 52 | Viewed by 17134

Abstract

Neurodegeneration is frequently associated with damage by free radicals. However, increases in reactive oxygen and nitrogen species, which may ultimately lead to neuronal cell death, do not necessarily reflect its primary cause, but can be a consequence of otherwise induced cellular dysfunction. Detrimental [...] Read more.

Neurodegeneration is frequently associated with damage by free radicals. However, increases in reactive oxygen and nitrogen species, which may ultimately lead to neuronal cell death, do not necessarily reflect its primary cause, but can be a consequence of otherwise induced cellular dysfunction. Detrimental processes which promote free radical formation are initiated, e.g., by disturbances in calcium homeostasis, mitochondrial malfunction, and an age-related decline in the circadian oscillator system. Free radicals generated at high rates under pathophysiological conditions are insufficiently detoxified by scavengers. Interventions at the primary causes of dysfunction, which avoid secondary rises in radical formation, may be more efficient. The aim of such approaches should be to prevent calcium overload, to reduce mitochondrial electron dissipation, to support electron transport capacity, and to avoid circadian perturbations. l-Theanine and several amphiphilic nitrones are capable of counteracting excitotoxicity and/or mitochondrial radical formation. Resveratrol seems to promote mitochondrial biogenesis. Mitochondrial effects of leptin include attenuation of electron leakage. Melatonin combines all the requirements mentioned, additionally regulates anti- and pro-oxidant enzymes and is, with few exceptions, very well tolerated. In this review, the perspectives, problems and limits of drugs are compared which may be suitable for reducing the formation of free radicals. Full article

(This article belongs to the Special Issue Neuroprotective Strategies)

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179 KiB

Open AccessArticle

Synthesis and Antitumor Activities of Phenanthrene-Based Alkaloids

by Songtao Li, Li Han, Liang Sun, Dan Zheng, Jiang Liu, Yingbo Fu, Xueshi Huang and Zhanyou Wang

Molecules 2009, 14(12), 5042-5053; https://doi.org/10.3390/molecules14125042 - 7 Dec 2009

Cited by 12 | Viewed by 10958

Abstract

A series of phenanthrene-based tylophorine derivatives (PBTs) were synthesized and their cytotoxic activities against the H460 human large-cell lung carcinoma cell line were evaluated. Among these compounds, N-(3-hydroxy-2,6,7-tri-methoxyphenanthr-9-ylmethyl)-L-prolinol (5a), and N-(3-hydroxy-2,6,7-trimethoxy-phenanthr-9-ylmethyl)-L-valinol (9) exhibited good activities, with IC [...] Read more.

A series of phenanthrene-based tylophorine derivatives (PBTs) were synthesized and their cytotoxic activities against the H460 human large-cell lung carcinoma cell line were evaluated. Among these compounds, N-(3-hydroxy-2,6,7-tri-methoxyphenanthr-9-ylmethyl)-L-prolinol (5a), and N-(3-hydroxy-2,6,7-trimethoxy-phenanthr-9-ylmethyl)-L-valinol (9) exhibited good activities, with IC₅₀ values of 11.6 and 6.1 mM, respectively. Full article

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550 KiB

Open AccessArticle

Dissolution of Microcrystalline Cellulose in Phosphoric Acid—Molecular Changes and Kinetics

by Junhua Zhang, Jingqiang Zhang, Lu Lin, Tianming Chen, Jun Zhang, Shijie Liu, Zhenjiang Li and Pingkai Ouyang

Molecules 2009, 14(12), 5027-5041; https://doi.org/10.3390/molecules14125027 - 4 Dec 2009

Cited by 99 | Viewed by 15509

Abstract

In this study, we aimed to dissolve microcrystalline cellulose (MCC) with phosphoric acid to obtain high-quality fermentable saccharides. MCC was directly dissolved in phosphoric acid (the concentration was 83%) for 10 hours at temperatures of 30, 50, and 70 °C. The structural changes [...] Read more.

In this study, we aimed to dissolve microcrystalline cellulose (MCC) with phosphoric acid to obtain high-quality fermentable saccharides. MCC was directly dissolved in phosphoric acid (the concentration was 83%) for 10 hours at temperatures of 30, 50, and 70 °C. The structural changes of MCC were determined in detail with X-ray powder diffraction, solid-state cross-polarization magic angle spinning ¹³C-NMR, and X-ray photoelectron spectroscopy. The kinetics of MCC decrystallization during treatment with phosphoric acid was also compared at 30, 50, and 70 °C. With the assumption of first order kinetics, the Arrhenius parameters of K, A₀ and E_a were calculated. The rate constants of decrystallization reaction (K) were 0.06, 0.17, and 0.12 h^-1 respectively. The pre-exponential factor (A₀) was 1.2 × 10⁶ h^-1, and the activation energy (E_a) was 42.4 kJ/mol. Full article

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452 KiB

Open AccessArticle

Effects of α-Melanocortin Enantiomers on Acetaminophen-Induced Hepatotoxicity in CBA Mice

by Petra Turčić, Mirna Bradamante, Karlo Houra, Nikola Štambuk, Tomislav Kelava, Paško Konjevoda, Saša Kazazić, Dražen Vikić-Topić and Biserka Pokrić

Molecules 2009, 14(12), 5017-5026; https://doi.org/10.3390/molecules14125017 - 2 Dec 2009

Cited by 10 | Viewed by 11265

Abstract

Proteins and peptides in mammals are based exclusively on L-amino acids. Recent investigations show that D-amino acids exhibit physiological effects in vivo, despite of their very small quantities. We have investigated the hepatoprotective effects of the Land D-enantiomers of α-melanocortin peptide (α-MSH). [...] Read more.

Proteins and peptides in mammals are based exclusively on L-amino acids. Recent investigations show that D-amino acids exhibit physiological effects in vivo, despite of their very small quantities. We have investigated the hepatoprotective effects of the Land D-enantiomers of α-melanocortin peptide (α-MSH). The results showed that peptideenantiomerism is related to the protective effects of melanocortin peptides in vivo. L-α-MSH exhibited potent hepatoprotective effect in the experimental model of acetaminophen induced hepatotoxicity in male CBA mice, while its D-mirror image was inefficient. Furthermore, the antibody to the L-peptide did not recognize the D-structure. The results indicate that the opposite peptide configuration may be used to modulate its function and metabolism in vivo and in vitro. Full article

(This article belongs to the Special Issue Prodrugs)

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278 KiB

Open AccessArticle

18-Crown-6 and Dibenzo-18-crown-6 Assisted Extraction of Cesium from Water into Room Temperature Ionic Liquids and Its Correlation with Stability Constants for Cesium Complexes

by Andrey Grigoryevich Vendilo, Dmitry Ivanovich Djigailo, Svetlana Valeryevna Smirnova, Irina Ivanovna Torocheshnikova, Konstantin Ivanovich Popov, Vladimir Georgyevich Krasovsky and Igor Vladimirovich Pletnev

Molecules 2009, 14(12), 5001-5016; https://doi.org/10.3390/molecules14125001 - 2 Dec 2009

Cited by 31 | Viewed by 13713

Abstract

The pH-profiles of the extraction of Cs⁺ into four conventional (1-butyl-3-methylimidazolium hexafluorophosphate and bis[trifluoromethyl)sulphonyl]imides of 1-butyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium, and 1-(2-ethylhexyl)-3- methylimidazolium) and two novel (trioctylmethylammonium salicylate and tetrahexylammonium dihexylsulfosuccinate) room temperature ionic liquids have been determined both in the absence and in the [...] Read more.

The pH-profiles of the extraction of Cs⁺ into four conventional (1-butyl-3-methylimidazolium hexafluorophosphate and bis[trifluoromethyl)sulphonyl]imides of 1-butyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium, and 1-(2-ethylhexyl)-3- methylimidazolium) and two novel (trioctylmethylammonium salicylate and tetrahexylammonium dihexylsulfosuccinate) room temperature ionic liquids have been determined both in the absence and in the presence of crown ether (18-crown-6 or dibenzo-18-crown-6). The pH-profiles of distribution ratio of crown ethers have been established in the same conditions. The relationship of cesium extraction efficiency both with the stability of its complexes with crown ethers and crown ethers’ distribution ratio has been clarified. Full article

(This article belongs to the Collection Ionic Liquids)

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769 KiB

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Hepatoprotective Potential of Extracts from Seeds of Areca catechu and Nutgalls of Quercus infectoria

by Pimolpan Pithayanukul, Saruth Nithitanakool and Rapepol Bavovada

Molecules 2009, 14(12), 4987-5000; https://doi.org/10.3390/molecules14124987 - 1 Dec 2009

Cited by 75 | Viewed by 12918

Abstract

Aqueous extracts from seeds of Areca catechu L. (Arecaceae) (AC) and nutgalls of Quercus infectoria Oliv. (Fagaceae) (QI) were investigated for their hepatoprotective potential by studying their antioxidant capacity using four different methods, by determining their in vitro anti−inflammatory activity against 5-lipoxygenase, and [...] Read more.

Aqueous extracts from seeds of Areca catechu L. (Arecaceae) (AC) and nutgalls of Quercus infectoria Oliv. (Fagaceae) (QI) were investigated for their hepatoprotective potential by studying their antioxidant capacity using four different methods, by determining their in vitro anti−inflammatory activity against 5-lipoxygenase, and by evaluating their hepatoprotective potential against liver injury induced by carbon tetrachloride (CCl₄) in rats. AC and QI extracts exhibited potent antioxidant and anti-inflammatory activities. Treatment of rats with AC and QI extracts reversed oxidative damage in hepatic tissues induced by CCl₄. It is suggested that extracts rich in either condensed or hydrolysable tannins and known for their potent antioxidant and anti-inflammatory activities, may potentially confer protection against oxidative stress−induced liver injury. These data should contribute to evidence-based traditional medicines for anti-inflammatory and hepatoprotective effects of both extracts. Full article

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Molecules, Volume 14, Issue 12 (December 2009) – 42 articles , Pages 4804-5388

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