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Zayniddin K. Muhidinov

Zayniddin K. Muhidinov

Institute of Academy of Sciences of the Tajikistan Republic

Title: Characterization of a polysaccharide from Eremurus hissaricus roots growing in Tajikistan

Biography

Zayniddin K. Muhidinov obtained his University degree in Chemistry at the Tajik State University and a Ph.D. in Chemistry of Natural Compounds and Doctor of Science degree in Polymer Chemistry at Chemistry Institute of Academy of Sciences of the Tajikistan Republic. Dr. Muhidinov passed doctoral courses at the All India Institute of Medical Sciences, New Delhi, India in 1998-1999 and the Temple University, Philadelphia, PA USA in 2003. In last 14 years his group collaborating with USDA scientists in several projects pertaining to develop domestic agricultural byproducts into Drug Delivery Systems (DDS) for therapeutic purposes. His most recent project deals with  the study of herbal biological active compounds. Professor Muhidinov is the author of a monograph; four chapters of the book (published by the American Chemical and Royal Societies) more than 290 scientific articles and abstracts, including 38 paper in peer reviewd journals, 10 patebts.

 

Abstract

Statement of the Problem: Roots of medical plants are important resources of bioactive compounds including a polysaccharide, many of which, have been reported to possess various biological functions. Two types of water-soluble (WSP) and acid-soluble polysaccharides (ASP) with 23%  and 8% yields, the molecular weight of 495 kDa and 179 kDa respectively were obtained from the roots of Eremurus hissaricus growing in Tajikistan in dormancy periods. The crude polysaccharides after deproteinization were purified by ion-exchange and gel filtration chromatography to obtain a homogeneous polysaccharide. The monosaccharide composition of WSP and ASP were analyzed by HPAEC-PAD. WSP was composed of D- mannose and D- glucose in 1.7:1 molar ratio. ASP content includes the pectic polysaccharide. IR spectra and analysis of 2D NMR analyses of WSP provide evidence that it has a backbone of (1→4)-linked ß-D-glucopyranosyl and ß-D-mannopyranosyl. The NMR and FTIR spectra of both crude and purified WSP has no differences. This fact probably indicates that WSP has no significant  impurity. The carboxyl group of WSP is highly esterified. The  NMR  analyses of the ASP and deproteinated ASP polysaccharides suggest that the samples are composed of rhamnose, galactose or glucose, xylose, and arabinose, with partially methyl- and acetylated carboxyl groups, which may be consistent with a branched pectic rhamnogalacturonan. Unfortunately, monosaccharide analysis has not yet been performed on these samples.  The NMR spectra of the ASP-S3 sample is similar to the other two, but it appears to lack resonances assignable to xylose.  It is unclear what this means. The bands at 801 cm-1 in the FTIR of the ASP samples were characteristic of the a-pyranose configuration of sugar unit of the pectin polysaccharide, while the absorption in the region of 880-890 cm-1 confirms the presence of ß-pyranose configuration of another sugar residue in the WSP.

Fig. 1. Tuber roots of Eremurus Hissaricus (1&2) and schema for extraction (3), purification of WS- and AS- polysaccharides (4) and structural analysis (5).