Medical Library

A highly efficient and selective synthesis of 1,2,3-triazole linked saccharide nucleosides via \”click chemistry\”.

A series of 1,2,3-triazole linked saccharide nucleosides were synthesized in high yield and selectivity via \”click chemistry\” of the 3\’-azido-2\’-deoxythymidine and the propargyl carbohydrates. [image omitted].

Ding H, Yang R, Song Y, Xiao Q, Wu J.

Jiangxi Key Laboratory of Organic Chemistry, Jiangxi Science & Technology Normal University, Jiangxi, P. R. China.

Novel N-3 Substituted TSAO-T Derivatives: Synthesis and Anti-HIV-Evaluation.

Novel derivatives of the anti-HIV-1 agent, TSAO-T, bearing at the N-3 position alkylating groups or photoaffinity labels were prepared and evaluated for their anti-HIV activity. All of these compounds demonstrated pronounced anti-HIV-1 activity and inhibited HIV-1 RT; however, we were unable to detect stable covalent linkages between inhibitor and enzyme. In addition, compounds with an alcohol functional group connected to the N-3 position through a cis or trans double bond have been prepared. These compounds have been useful to study how the conformational restriction of the linker affects in the interaction between the N-3 substituent and the HIV-1 RT enzyme.

Bonache MC, Quesada E, Sheen CW, Balzarini J, Sluis-Cremer N, Pérez-Pérez MJ, Camarasa MJ, San-Félix A.

Instituto de Química Médica (C.S.I.C.), Madrid, Spain.

Diastereomer separation of azobenzene-tethered oligodeoxyribonucleotides and determination of their absolute configurations by enzymatic digestion.

Two diastereomers were produced by the introduction of azobenzene-tethering prochiral linker (2,2-bis(hydroxymethyl)propionic acid) in the modified ODN, which had been used for the photoregulation of DNA functions. We found that this modified ODN with sequence 5\’-…pNpXpN…-3\’ (p = phosphate; N = nucleoside; X = azobenzene residue) could be digested to pX (the phosphate at the 5\’ side of X was left) by an over excess of Phosphodiesterase I. By comparing the retention time of pX from the separated diastereomer with that of authentic R- or S-pX on chiral HPLC, absolute configuration could be easily determined.

Liang X, Komiyama M, Asanuma H.

Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Nagoya, Japan.

Acyclic Phosphonate Nucleotides and Human Adenylate Kinases: Impact of a Borano Group on alpha-P Position.

Adenylate kinases are involved in the activation of antiviral drugs such as the acyclic phosphonates analogs PMEA and (R)PMPA. We examine the in vitro phosphorylation of PMEA and PMPA bearing a borano- or a H- group on the phosphorus atom. The alpha-borano or alpha-H on PMEA and PMPA were detrimental to the activity of recombinant human AMP kinases 1 and 2. Docking PMEA to the active site of AMP kinase 1 indicated that the borano group may prevent two conserved critical Arg interactions with the alpha-phosphate, resulting in substrate bad positioning.

Topalis D, Alvarez K, Barral K, Munier-Lehmann H, Schneider B, Véron M, Guerreiro C, Mulard L, El-Amri C, Canard B, Deville-Bonne D.

Laboratoire d\’Enzymologie, Université Paris, Paris, France.

Role of hypaphorine in the toxicity of Astragalus lusitanicus.

Hypaphorine, an alpha-N,N,N-trimethyltryptophan betaine, was isolated, for the first time, from Astragalus lusitanicus Lam. (Fabaceae), a plant highly toxic for lambs and goats. This alkaloid was characterized by NMR and MS analysis. Hypaphorine was previously reported to be a convulsive poison. To confirm the toxicity, it was synthesized and tested in goats. Hypaphorine was shown to be non-toxic for goats even at a high dose of 2 g kg(-1) by oral administration.

Bel-Kassaoui H, Lamnaouer D, Jossang A, Abdennebi el H, Charrouf Z, Bodo B.

Département de Pharmacie Toxicologie et Biochimie, Institut Agronomique et Vétérinaire Hassan II BP 6202, Rabat-Instituts, Morocco.

Effect of ethyl acetate extract from Marchantia convoluta on inhibition of human liver carcinoma HepG2 cells.

The effect of the dichloromethane fraction (DF) of the ethyl acetate extract from Marchantia convoluta on the inhibition of human liver carcinoma cell line HepG2 was investigated. DF can remarkably induce HepG2 cell apoptotic, accompanied by a decrease of the cell viability and an increase of the fraction of S-phase cells by 62.5% in a concentration-dependent manner.

Cao H, Chen JW, Tang B, Xu M.

Jiangsu Provincial Key Laboratory of Coastal Wetland Bio-resources and Environmental Protection, Yancheng Normal College, Jiangsu, P. R. China.

A new 3-arylcoumarin from the roots of an Egyptian collection of Lotus polyphyllos.

Further investigation of different fractions from Lotus polyphyllos Clarke roots resulted in the isolation of the new 3-arylcoumarin derivative; 4\’,6\’-dihydroxy-7, 2\’-dimethoxy-3-arylcoumarin (5). In addition, the known compounds beta-sitosterol, 1-hexacosanol (1), n-tetracosyl p-coumarate (2), 4\’-O-methylderrone (4), and quercetin (6) were identified. The structures were determined from spectroscopic data including 1D- and 2D-NMR experiments.

Abdel-Kader MS, Basudan OA, Parveen M, Amer ME.

Faculty of Pharmacy, Department of Pharmacognosy, King Saud University, Riyadh 11451, Saudi Arabia.

Isolation and structure determination of the cembranoid eunicin from a new genus of octocoral, Pseudoplexaura.

The known cembranoid diterpene eunicin (1) was isolated from a new genus of octocoral, Pseudoplexaura, collected in the Caribbean. The complete assignment of the (13)C and (1)H NMR spectra, including differentiation of pro-R and pro-S hydrogens and elucidation of all J values, was accomplished with the aid of TOCSY, HSQC, and HMBC data, and a consideration of three low-energy conformations using SYBYL.

Sponholtz WR, Bianco MA, Gribble GW.

Department of Science, Cushing Academy, Ashburnham, MA 01430, USA.

Phytotherapeutic inhibition of supragingival dental plaque.

Antimicrobial activities and biofilm-formation preventive properties of Mentha piperita and Cuminum cyminum essential oils and chlorhexidine were assessed against Streptococcus mutans and Streptococcus pyogenes. Gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analysis led to the identification of 26 and 32 compounds in the essential oils of M. piperita and C. cyminum, respectively. Minimal bactericidal concentrations (MBC) of the oils and chlorhexidine and microbial decimal reduction time (D value) were determined. Antibacterial and in vivo biofilm preventive efficacies of all the concentrations of M. piperita oil were significantly (p<0.001) higher. The biofilm inhibitory properties in planktonic cultures were in M. piperita > chlorhexidine > C. cyminum order. In vivo experiments conducted on male and female volunteers who brushed with essential oil blended toothpastes indicated that lower concentrations of the oils, in particular the M. piperita oil, were significantly higher (p<0.001) and effective during the course of the study as compared to chlorhexidine. In conclusion, there may be a potential role for essential oils in the development of novel anticaries treatments.

Shayegh S, Rasooli I, Taghizadeh M, Astaneh SD.

Department of prosthetics, College of Dentistry, Shahed University, Tehran, Iran.

An experimental study of the effects of Matricaria chamomilla extract on cutaneous burn wound healing in albino rats.

Previous studies conducted on the anti-inflammatory, antimicrobial and antioxidant effects of Matricaria chamomilla (chamomile) extract led us to study the effect of topical chamomile extract on burn wound healing in albino rats. Thirty male albino rats (250-300 g) were randomly divided into three groups, as control, vehicle, and treatment. Second-degree burning was induced in 20% of whole surface area of animal body by placing the back of animal into boiling water for 8s. Animals of control group received no treatment. Animals of vehicle and treatment groups were treated topically by olive oil and extract dissolved in olive oil twice a day respectively from the first day of burn induction to complete wound healing. The percentage of wound healing was calculated weekly. The results showed that there was significant difference (p < 0.05) between vehicle and treatment groups. So we concluded that the chamomile extract in the form of rubbing oil had a good potential for acceleration of burn wound healing in rats.

Jarrahi M.

Physiology Research centre, Semnan University of Medical Sciences, Semnan, Iran.