ISOLATION AND PHYSICO-CHEMICAL CHARACTERISTICS OF POLYSACCHARIDES IN THE SEEDS OF TURNIP BRASSICA RAPA

Abstract

The aim of this research is the isolation and physicochemical characterization of water-soluble polysaccharides in the seeds of the turnip Brassica rapa of the family Brassicaceae cultivated in Uzbekistan.
 For the first time, water-soluble polysaccharides were isolated from turnip seeds by sequential water extraction. Polysaccharides are deproteinized and separated by ion exchange chromatography, purified on a Sephadex G-100 column. Two polysaccharide fractions BSP-1-1 and BSP-2-1 were obtained. The results of IR spectroscopic studies showed that the isolated polysaccharides consist mainly of α-linked pyranose units. Analysis of the monosaccharide composition showed that the composition of the neutral polysaccharide BSP-1-1 is represented by monosaccharides in the following composition: ribose – 5.05%, arabinose – 56.38%, mannose – 5.87%, glucose – 8.63% and galactose – 24.05%. The composition of the anionic polysaccharide BSP-2-1 is represented by monosaccharides: ribose – 6.35%, arabinose – 60.15%, mannose – 7.19%, glucose – 4.12% and galactose – 22.16%. It was determined that the isolated polysaccharides consist mainly of arabinose (BSP-1-1 – 56.3%, BSP-2-1 – 60%) and galactose (BSP-1-1 – 24%, BSP-2-1 – 22%). Based on the data obtained, it can be assumed that the studied polysaccharides from the seeds of the turnip Brassica rapa belong to the type of arabinogalactans.