从埃及绒毛黄芪中分离出的三种新环阿尔廷型皂苷的缩醛。

Acetals of three new cycloartane-type saponins from Egyptian collections of Astragalus tomentosus.

作者信息

Radwan Mohamed M, Farooq Afgan, El-Sebakhy Nadia A, Asaad Aya M, Toaima Soad M, Kingston David G I

机构信息

Department of Chemistry, M/C 0212, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA.

出版信息

J Nat Prod. 2004 Mar;67(3):487-90. doi: 10.1021/np030395a.

DOI:10.1021/np030395a

PMID:15043441

Abstract

Three new cycloartane-type saponin ethyl acetals, deacetyltomentoside I (2), tomentoside III (3), and tomentoside IV (4), were isolated along with the known acetal tomentoside I (1) from the aerial parts of Astragalus tomentosus of Egyptian origin. The saponins from which the acetals are most probably derived are also new compounds. The structures of the acetals were established as 6alpha-hydroxy-23alpha-ethoxy-16beta,23(R)-epoxy-24,25,26,27-tetranor-9,19-cyclolanosta-3-O-beta-d-xyloside (2), 6alpha-acetoxy-23alpha-ethoxy-16beta,23(R)-epoxy-24,25,26,27-tetranor-9,19-cyclolanosta-3-O-[beta-d-(4'-trans-2-butenoyl)]xyloside (3), and 6alpha-acetoxy-23alpha-ethoxy-16beta,23(R)-epoxy-24,25,26,27-tetranor-9,19-cyclolanosta-3-O-[beta-d-glucopyranosyl(1 --> 2)]-beta-d-xyloside (4), by detailed spectroscopic and chemical studies.

摘要

从埃及产绒毛黄芪地上部分中，分离得到了三种新的环阿尔廷烷型皂苷乙缩醛，即去乙酰绒毛皂苷I（2）、绒毛皂苷III（3）和绒毛皂苷IV（4），以及已知的乙缩醛绒毛皂苷I（1）。这些乙缩醛最可能衍生自的皂苷也是新化合物。通过详细的光谱和化学研究，确定了乙缩醛的结构分别为6α-羟基-23α-乙氧基-16β,23(R)-环氧-24,25,26,27-四降-9,19-环羊毛脂烷-3-O-β-D-木糖苷（2）、6α-乙酰氧基-23α-乙氧基-16β,23(R)-环氧-24,25,26,27-四降-9,19-环羊毛脂烷-3-O-[β-D-(4'-反式-2-丁烯酰基)]木糖苷（3）和6α-乙酰氧基-23α-乙氧基-16β,23(R)-环氧-24,25,26,27-四降-9,19-环羊毛脂烷-3-O-[β-D-吡喃葡萄糖基(1→2)]-β-D-木糖苷（4）。