| Taxus media a kind of indeciduous arbor or shrub,spreads in the Northern hemisphere and the number of the varieties is eleven in the world. There are four varieties which are Taxus mairei, Taxus wallichiana var.mairei, Taxus wallichiana zucc,Taxus chinensis in our country.At present,paclitaxol is mainly researched and used to cure cancer .But little research on chemical structure about polysaccharides of Taxus media was reported up to now inside and abroad.The overground part of Taxus mairei was extracted by water,and precipitated with ethol,obtained precipitate (TP) and supernatant (TS).By super filter TP was separated into two portions TP-3 and TP-4.They were analysed by inorganic elements and HPGPC,the result showed that TP-4 was composed of salt and digosaccharide,TP-3 was mainly polysaccharides. The yield of TP-3 was the most,so it was taken more research.TP-3 was composed of Rha,Ara,Man,Glu,Gal,GalA,GlcA,percent mole of them were 1.83 %,25.77 %,2.82 %,2.78 %,10.89%,52.19%,3.71%.Methlated analysis showed that it had (1→3)-linked Gal as a main chain with the branching point at 4-0,6-0,(1→2,1→3)-linked Rha with the branching point at 4-0,(1→4)-linked Man and Ara ,Glu as the nonrevived end. So we deduced that TP-3 was pectic polysaccharides. After partly hydrolysis and precipitating with ethol,the precipitate of TP-3 was applied to Sephadex G-75 column,and was fractioned into seven portions .HPGPC showed that TP-3s-3 was the main chain of TP-3 which was mainly composed of GalA,Rha,Gal and little Man,Glu.Acording to the result of GC-MS,TP-3s-3 had (1→3,1→4)-linked Gal with the branching point at 6-0 ; (1→2)-linked Rha with the branching point at 4-0 ; little (1→4,1→6)-linked Man and (1→3,1→4)-linked Glu; Gal,Rha at nonrevived end. Special methlated showed that GalA was (1→4)-linked.At last we deduced that TP-3s-3 had (1→4)-linked GalA and (1→2)-linked Rha as the main chain with the branching point at 4-0 of Rha; the side chain was mainly composed of (1→3,1→4)-linked Gal.
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