Isolation and identification of steroidal saponins in total saponin from Dioscorea nipponica Makino
Du, S.-h.; Liu, W.-y.; Fu, T.-j.; Xia, B.-g.; Xia, C.-d.
Yao Xue Xue Bao 37(4): 267-270
2002
ISSN/ISBN: 0513-4870 PMID: 12579821 Document Number: 545586
To investigate the water-soluble steroidal saponins in total saponin from Dioscorea nipponica Makino and look for new active compounds. 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. 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). Compound II is a new steroidal saponin and firstly isolated from Dioscorea nipponica Makino. It was named as dioscin Dc.