Saponin and sapogenol. XXXV. Chemical constituents of astragali radix, the root of Astragalus membranaceus Bunge. (2). Astragalosides I,II and IV, acetylastragaloside I and isoastragalosides I and II.
作者:ISAO KITAGAWA、HUIKANG WANG、MASAYUKI SAITO、AKIRA TAKAGI、MASAYUKI YOSHIKAWA
DOI:10.1248/cpb.31.698
日期:——
Twelve triterpene-oligoglycosides were isolated from the glycosidic constituents of Astragali Radix, the root of Korean Astragalus membranaceus BUNGE. (Leguminosae). They were acetylastragaloside I (3), isoastragalosides I (5) and II (7), astragalosides I (4, major), II (6), III, IV (8), V, VI and VII, which contain a 9, 19-cyclolanostane cycloastragenol (1) as the aglycone, and astragaloside VIII and soyasaponin I (9), which possess an oleanene-type aglycone, soyasapogenol B. By means of chemical degradations, which included a selective cleavage method for the glucuronide linkage, and 13C-NMR examinations, the structure of astragaloside IV was elucidated as 3-O-β-D-xylopyranosyl-6-O-β-D-glucopyranosylcycloastragenol (8). In addition, the structures of five acetyl derivatives of 8 : acetylastragaloside I, astragaloside I, isoastragaloside I, astragaloside II and isoastragaloside II, were elucidated as 3-O-β-(2', 3', 4'-tri-O-acetyl)-D-xylopyranosyl- (3), 3-O-β-(2', 3'-di-O-acetyl)-D-xylopyranosyl- (4), 3-O-β-(2', 4'-di-O-acetyl)-D-xylopyranosyl- (5), 3-O-β-(2'-O-acetyl)-D-xylopyranosyl- (6) and 3-O-β-(3'-O-acetyl)-D-xylopyranosyl-6-O-β-D-glucopyranosylcycloastragenol (7), respectively.
从朝鲜黄芪(Astragali Radix)(豆科植物朝鲜黄芪的根)的苷元成分中分离出 12 种三萜类寡糖苷。豆科它们是乙酰黄芪苷 I (3),异黄芪苷 I (5) 和 II (7),黄芪苷 I (4,主要),II (6),III,IV (8),V,VI 和 VII,其中含有 9,19-环羊毛甾烷环黄芪烯醇 (1) 作为苷元,以及黄芪苷 VIII 和大豆皂苷 I (9),其中含有齐墩果烯型苷元--大豆皂苷 B。通过化学降解(包括葡萄糖醛酸连接的选择性裂解方法)和 13C-NMR 检测,阐明了黄芪皂苷 IV 的结构为 3-O-β-D-xylopyranosyl-6-O-β-D-glucopyranosylcycloastragenol (8)。此外,8 的五个乙酰基衍生物的结构 :乙酰基黄芪皂甙 I、黄芪皂甙 I、异黄芪皂甙 I、黄芪皂甙 II 和异黄芪皂甙 II 的结构分别为 3-O-β-(2',3',4'-三-O-乙酰基)-D-xylopyranosyl- (3)、3-O-β-(2',3'-二-O-乙酰基)-D-xylopyranosyl- (4)、3-O-β-(2', 4'-di-O-acetyl)-D-xylopyranosyl- (5)、3-O-β-(2'-O-乙酰基)-D-xylopyranosyl- (6)和 3-O-β-(3'-O-乙酰基)-D-xylopyranosyl-6-O-β-D-glucopyranosylcycloastragenol (7)。