From fresh rhizome of Alisma orientale, and the crude drug Alismatis r
hizoma of Japanese and Chinese origins, 15 new terpenoids were isolate
d together with 11 known terpenoids and were characterized as follows:
11-deoxy, 13 beta,17 beta-epoxy and 11-deoxy-13 beta,17 beta-epoxy de
rivatives of alisols, alisol C, 16,23-oxidoalisol B, 25-O-methyl and 2
5-anhydro derivatives of alisol A, as well as eudesma-4(14)-en-1,6-dio
l, 10-O-methyl-alismoxide and 16( R)-(-)kaurane-2,12-dione.