Parvifloside (1), a new furostanol pentaglycoside, was isolated from the fresh rhizomes of Dioscorea parviflora C. T. Ting. On the basis of spectroscopic and chemical methods, its structure was elucidated as (25R) 26 O β glucopyranosyl furost 5 en 3β,22ξ,26 triol 3 O βD glucopyranosyl (1→3) βD glucopyranosyl (1→4) ［αL rhamnopyranosyl (1→2)］ βD glucopyranoside. Six prosapogenins (2-7) were obtained from the enzymatic degradation of 1 by cellulase, but only 3 and 4 were obtained by β glucosidase. The structures of all compounds were determined by spectroscopic data. The activity of the isolated compounds on deformation of mycelia germinated from Pyricularia oaryzae P 2b conidia was evaluated.
小花盾叶薯蓣甙的酶降解
金建明 刘锡葵 滕荣伟 杨崇仁*
（中国科学院昆明植物研究所植物化学与西部植物资源持续利用国家重点实验室，昆明650204）
摘要： 从小花盾叶薯蓣 (Dioscoreaparviflora C.T .Ting)的新鲜根状茎中分离到一个新的呋甾烷型配糖体 ,命名为小花盾叶薯蓣甙 (parvifloside) (1) ,其结构通过波谱和化学方法鉴定为 :(2 5R)-2 6-O-β-glucopyranosyl-furost-5-en-3β ,2 2 ξ ,2 6-triol 3-O-β-D-glucopyranosyl (1→ 3)-β-D-glucopyranosyl (1→ 4 )-[α-L-rhamnopyranosyl (1→ 2 ) ]-β-D-glucopyra noside。化合物 1在纤维素酶粗酶和 β_葡萄糖苷酶中进行水解 ,得到降解产物 2 - 7。对 1的酶解现象进行了讨论。同时 ,对所分离的甾体皂甙的抗稻瘟霉菌活性进行了初步筛选。
关键词： 小花盾叶薯蓣；小花盾叶薯蓣甙；甾体皂甙；酶降解
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