Journal of Purity, Utility Reaction and Environment Vol.3 No.3, June 2014, 50-61 Daiekh A. A. Abod 1 , AL-Bader S. M. 2 Mohammed A. AL-Saeedy 3 1 Faculty of Medicine and Health Science-University of Thamar- Yemen 2 Faculty of Applied Science –University of Thamar-Yemen 3 Al-Saeedy M A – College of Education-University of Al- Baidy- Yemen Synthesis of New D-xylose Derivatives and Study Their Antimicrobial Effect Article Info Received: 8 th March 2014 Accepted: 1 st May 2014 Published online: 1 st June 2014 ISSN (Online): 2232-1179 I ISSN (Print): 2314-8101 © 2012 Design for Scientific Renaissance All rights reserved ABSTRACT D - xylose was converted into new allylic furanosyl and pyranosyl glycosides by applying two different reaction conditions. The glycosides then were treated with sodium azide to get triazoline compounds via a 1,3-dipolar cycloaddition. The new glycosides and the triazoline the synthesized derivatives were screened for in vitro antimicrobial activity (S.aureus , E.coli) and fungal (Candida albicans) which were isolated from human infections. The study revealed that the triazoline derivatives exhibit promising antibacterial and antifungal activities. The triazoline derivatives were found to be more effective against the fungal strains than those of the bacterial pathogens. However, a good number of derivatives glycosides exhibited better antimicrobial activity than the standard antibiotics. Compounds were identified by I.R,1H – and 13C – NMR spectroscopy. Keywords: D- xylose, derivatives, glycosides, triazoline, antimicrobial activity. Hhh hhhhhhhhhhhhhhh 1. Introduction The study of glycosides is one of the exciting fields of organic chemistry. Glycosides are important biological molecules that are involved in a vast number of biological processes [Nicotra et al., 2008]. Many glycosides have therapeutic uses such as anti-cancer therapies, anti-inflammatory, enzyme inhibitors and antibiotics [Hanessian and Lou, 2000]. It is very important due to their effective biological activity [Andry et al., 1982]. It is also known that if an active nucleus or molecule is linked to another nucleus, the resulting molecule may possess