Abstract
Three new diterpenoids, in addition to trans-communol (1), trans-communic acid [obtained in the form of the methyl ester (2)], isomimaran-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) and ent-17-norkauran-16-one (7), were isolated as non basic constituents of the crude drug "Fritillariae Bulbus" prepared from the bulbs of Fritillaria thunbergii MIQ. by treatment with lime followed by bleaching in the sun. These three diterpenoids were determined to be ent-15β, 16-epoxy-kauran-17-ol (8), ent-16β-hydroxy-kauran-17-yl ent-kaur-15-en-17-oate (9) and ent-(16S)-atisan-13, 17-oxide (10).
