Diterpenoids from bulbus of Fritillaria monanth

To study the chemical constituents of Fritillaria monanth Migo, the constituents were separated and purified by column chromatography on silica gel, and the structures were identified by NMR, MS spectral data. Six compounds were isolated and identified as ent-kauran-15-en-17-ol (I), ent-kauran-15-en-3α,17-diol (II), fritillaziebinol (III), ent-kauran-16α,17-diol (IV), ent-kauran-3α，16α,17-triol (V), ent-16,17-epoxy-kauran-3α-ol (VI). All the compounds were isolated from this plant for the first time, and VI is named as ent-16,17-epoxy-kauran-3α-ol, which is a new compound.