[Isolation and identification of steroidal saponins in total saponin from Dioscorea nipponica Makino].
OBJECTIVE
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).


CONCLUSIONS
Compound II is a new steroidal saponin and firstly isolated from Dioscorea nipponica Makino. It was named as dioscin Dc.
Du
Shu-hu
SH
Anhui Institute of Medical Sciences, Hefei 230061, China. dushuhu@ah163.com
Liu
Wen-ying
WY
Fu
Tie-jun
TJ
Xia
Bo-gang
BG
Xia
Chong-dao
CD
D027742:Dioscorea / Q000737:chemistry*; D008968:Molecular Conformation; D015394:Molecular Structure; D010946:Plants, Medicinal / Q000737:chemistry*; D027343:Rhizome / Q000737:chemistry; D012503:Saponins / Q000737:chemistry / Q000302:isolation & purification*
D012503:Saponins; C479298:diosgenin 3-O-(rhamnopyranosyl-1-3-rhamnopyranosyl-1-4-rhamnopyranosyl-1-4)glucopyranoside; C479299:diosgenin 3-O-(rhamnopyranosyl-1-2-(glucopyranosyl-1-3))glucopyranoside