An echinocystic acid saponin derivative from Kalimeris shimadae.

A new triterpene saponin, shimadoside A, has been isolated from Kalimeris shimadae and its structure deduced as 3-O-beta-D-glucopyranosiduronic acid-3 beta, 16 alpha-dihydroxyolean-12-en-28-oic acid-28-O-beta-D-xylopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1--> 4)-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-xylopyranoside by means of spectral data, especially NMR, including COSY, HMQC, HOHAHA and ROESY techniques, and chemical degradation.