Study On Extraction, Separation, Purification And Structure Of Polysaccharide From Abalone Viscus

Polysaccharide was extracted from abalone viscus by enzyme deproteinization. It was showed that the optimum hydrolytic conditions of single enzyme is alkaline proteinase on pH10.0 for 3 hours at 45?, substrate concentration 2.5%, enzyme dosage 2.0%. The polysaccharide yield ratio can reach to 6.5%.According to the deproteinization rate and the yield of polysaccharide, the methods of enzyme, TCA and Sevag were tested on deproteinization. The results showed that enzymic method was better than the others and the deproteinization rate was 68.8%.Abalone viscus polysaccharide was deproteinizd by pepsin and the method of Sevag.Then Purified by sephadex G-100 gel and DEAE——cellulose chromatography. Finally we got the AHP-2. Chemical composition analysis indicated that AHP-2 was sulphated polysaccharide. No protein absorption was shown in UV spectrum, but typical absorption of polysaccharide and sulphuric acidyl was shown in IR spectrum; AHP-2 was a single homogeneous polysaccharide with molecular weight of 10,000-15,000, and the content of sulphate was 11.55%. It was composed of rhamnose, fucose, xylose, galactose and glucose. The ratio was Rha: Fuc: Xyl: Gal: Glu=6.7:2.0:3.9:7.4:1.0.Partial hydrolysis with TFA, Periodate oxidation, Smith degradation, I.R. and Methylation were used on the structure analysis of AHP-2. After acetylation, the methylated productions were analyzed by G.C- MS and NMR. The results revealed that the main chain was composed of Gal and Rha, and the proportion was 1:1. Rha(1?3) and Gal(1?3,6) linked alternately, and on the average, there was a point of branching between every two monosaccharides. The branched chain and main chain edge were composed of Rha, Xyl and Gal. Fuc and Glc existed on the branched chains edge of surrounding. Gal was in the form of (1?4), (1?6) glycosidic bond; Xyl was in the form of (1?2) glycosidic bond and Fuc was in the form of (1?4) glycosidic bond. Extremities were composed of Glc, Gal and Fuc. So its possible repeated unit was: A, B and C were composed of Gal(1?4), (1?6), Xyl (1?2), Fuc(1?4). Branched chains were mainly composed of Gal(1?4), (1?6) and Xyl(1?2). Extremities were composed of Fuc, Glc and Gal.