【摘要】 <正> 前文报道从中药膜荚黄芪（Astragalus membranaceus Bunge）根部分离得到三个皂苷ASI、AS Ⅱ和 AS Ⅲ.AS Ⅰ和 AS Ⅱ分别称为膜荚黄芪苷（astramembrannin）Ⅰ（1）和Ⅱ（2）,AS Ⅲ经鉴定为胡罗卜苷（dancosterin）（3）.本文报道1和2的结构测定.1为主要成份,具有降压、抗炎、镇静、镇痛和调节代谢的作用.1和2经 Smith 降解均得苷元4^**,用酸水解经鉴定1含有木糖和葡萄糖,2仅含木糖.更多还原

【Abstract】 Astragalus saponlns AS Ⅰ,AS Ⅱ isolated from the roots of A.membranaceus Bunge（Leguminosae）were named astramembrannin Ⅰ（1）and Ⅱ（2）respectively.1 was hydrolyzedby dilute acid to give secondary glycosides 2 and 5.On the basis of the spectrascopic dataof 1,2 and their peracetate and permethyl ether(¹H NMR,¹³C NMR,IR and MS),thestructure of 1 and 2 were established as 3-O-β-D-xylopyranosyl-6-O-β-D-glucopyra-noside and 3-O-β-D-xylopyranoside of astramembrangenin（4）respectively.The thirdsaponin AS Ⅲ was identified as dancosterin（3）.更多还原