The present invention relates to a composition enriched with 3-0-[O-.alpha.-L-rhamnopyranosyl-(1.fwdarw.2)-[0-.beta.-D-glucopyranosyl-- (1-.fwdarw.4)]-.alpha.-L-arabinopyranosyl]hederagenin (Code No. SB 365) of which antitumor activity is very strong by enzyme-reacting and extracting Pulsatillac radix.