穿龙薯蓣总皂苷中甾体皂苷的分离与鉴定

目的研究穿龙薯蓣总皂苷中水溶性甾体皂苷,寻找新的生物活性化合物。方法用硅胶柱色谱、薄层色谱及高效液相色谱等进行分离,通过酸水解、理化常数和波谱学分析(IR,NMR,MS,HMQC,HMBC)鉴定化合物结构。结果从穿龙薯蓣总皂苷中分得2个甾体皂苷(1个水难溶性皂苷和1个水溶性皂苷),其化学结构分别鉴定为薯蓣皂苷元-3-O-{α-L-鼠李糖(1→2)-［β-D-葡萄糖(1→3)］}-β-D-葡糖皂苷(I),薯蓣皂苷元-3-O-［α-L-鼠李糖(1→3)-α-L-鼠李糖(1→4)-α-L-鼠李糖(1→4)］-β-D-葡糖皂苷(II)。结论II为首次从穿龙薯蓣中分离得到的新化合物,命名为穿龙薯蓣皂苷Dc。

ISOLATION AND IDENTIFICATION OF STEROIDAL SAPONINS IN TOTAL SAPONIN FROM DIOSCOREA NIPPONICA MAKINO

AIM: To investigate the water-soluble steroidal saponins in total saponin from Dioscorea nipponica Makino and look for new active compounds. METHODS: The compounds were isolated with silica gel, PTLC and HPLC, and their structures were elucidated by acid hydrolysis, physical and chemical data and spectral analysis (IR, NMR, MS, HMQC, HMBC) as well as chemical correlations. RESULTS: The two steroidal saponins (water-insoluble saponin and water-soluble saponin) were isolated from the total saponin of Dioscorea nipponica Makino. The structures were elucidated as diosgenin 3-O-alpha-L-rhamnopy ranosyl (1-->2)-beta-D-glucopyranosyl(1-->3)]]-beta-D-glucopyranoside (I), diosgenin 3-O-alpha-L-rhamnopyranosyl (1-->3)-alpha-L-rhamnopyranosyl (1-->4)-alpha-L-rhamnopyranosyl (1-->4)]-beta-D-glucopyranoside (II). CONCLUSION: Compound II is a new steroidal saponin and firstly isolated from Dioscorea nipponica Makino. It was named as dioscin Dc.