Screen Out Anti-NDV Polysaccharides Extracted From The Chinese Herbs

Newcastle Disease (ND) is one of infectious diseases, which may pose a huge threat and cause a great economic losses to poultry. Up to now, there is no effective curative drug for ND. The polysaccharides contained in Chinese herbs, which displays a huge potential therapeutic effect for ND having multiple effects such as enhancing immunity, anti-virus, low poison and less drug resistance.Our study on eight kinds of polysachharides extracted from the Chinese herbs and sulfated polysaccharides which were sulfating modity by the way of chlorosulfonic acid and pyridinium as potential anti-viral drugs.Through experiments find out effective polysaccharides having depressant effect to NDV,using cell culture as screening platform. We determined the ultrasonic extraction conditions of polysaccharide from Rheum tanguticum Maxim and rough determine those construction.The major studing contents as follow:By the tranditional ways, extract polysaccharides from eight types of herbs, and modify these to be sulfated polysaccharide through the way of chlorosulfonic acid and pyridine. In the screening platform of CEF, experiment screen out polysaccharides which have the anti-NDV effect in vitro, compare anti-viral effect of polysaccharides with each others.Study find all of polysaccharides have some effect to NDV, AGE and PPS have poorly effect, APS is best effect, RIP and ASP is secondary effect. The anti-viral effect is stem from cytoprotection of polysaccharides to CEF, not direct-lethal effect to NDV.Study proved that the anti-viral effect of ASP,ABPS and RTP can be raised by sulfate modify to these polysaccharides, and sRTP display some lethal effect to NDV.On the basis of single-factor study, ultrasonic extraction conditions of polysaccharide from Rheum tanguticum Maxim were obtained by the L943orthogonal design, while temperature of 40℃, time of 50 min, dry alage to water ratio of 1:40,pH9.0 was the optimum, the ratio of polysaccharide was 42.27% and the content of polysaccharide was 13.11% in this condition ultrasonic extraction which have a lot of advantage such as conserving power sources, high performance and not easy to destroy polysaccharides construction, is better comparing with traditional way.We can get a single eluting peak through SephadexG-50 and SephadexG-100 to classify RTP, that indicate RTP is compose with a main type polysaccharide.Through the analysis UV spectra to RTP and sRTP,there was strong absorption peak under the range of 190～220nm,proving RTP and sRTP contain of polysaccharides.sRTP have a strong absorption peak in 265nm,indicate sRTP contain of SO42-.Studys determine the SO42- content and DS of sRTP which is modify to RTP through chlorosulfonic acid and pyridine.The sRTP is react with BaSO4 gelatin 20min, is optima measure time determined by Stability experiment.The contents of SO42- is 6.04%,SD is 0.38, recovery rate is 90% in sRTP.The analysis of TLC proved RTP compose with glucuronic acid, glycose, isodulcite, xylose and arabinose. The analysis of infrared spectra (IR) indicated that sulfated esterification was succeed, sRTP IR figure adding to the feature absorption peak of -SO3 1156.6cm-1,885.5 cm-1 and 816.1cm-1 contrast to RTP, and RTP is pyran polysaccharide having glycuronic acid, pyranoside, be composed with a-D-glucopyranose, B-D-glucopyranose, a-D-galactopyranose, glycuronic acid, a-D-xylopyraose andβ-Larabopyranose.The study compared the anti-NDV effect of polysaccharides with sulfated polysaccharides and screened out effective polysaccharides. Experiment optimized condition of polysaccharides extraction from herbs, blest get uniform composition from RTP and acknowledge of its construction.Study of polysaccharides and sulfated polysaccharides will do the rationale base which are used to prevent and cure ND in clinic.