3-O-beta-D-xylopyranosyl(1-->3)-alpha-L-rhamnopyranosyl(1-->2)-alpha- L-arabinopyranosyl-23-hydroxy-olean-12-en-28-O-alpha-L- rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranosy l ester