Studies on the constituents of the crude drug "Fritillariae bulbus." III. On the diterpenoid constituents of fresh bulbs of Fritillaria thunbergii Miq.

Abstract

In addition to trans-communol and trans-communic acid (obtained in the form of the methyl ester), seven new diterpenoids were isolated as non basic constituents from fresh bulbs of Fritillaria thunbergii MIQ. (Liliaceae). Their structures were determined to be isopimaran-19-ol (3), isopimaran-19-oic acid [obtained in the form of the methyl ester (4)], ent-kauran-16β, 17-diol (5), ent-kauran-16α, 17-diol (6), ent-16β, 17-epoxy-kaurane (7), ent-16α-methoxy-kauran-17-ol (8), and ent-kaur-15-en-17-ol (9).