鄂北贝母二萜成分鄂贝醇的结构解析

Structural Elucidation of a New Diterpenoid, Fritillebinol from Ebeiensis Fritillary Bulb (Fritillaria ebeiensis)

在鄂北贝母 Ｆｒｉｔｉｌｌａｒｉａ ｅｂｅｉｅｎｓｉｓ鳞茎非生物碱的继续研究中，又分得６种对映－贝壳杉烷型二萜，经理化常数及波谱解析，并与标准品对照，证实晶Ⅰ ～Ⅲ的结构分别为 ｅｎｔ－ｋａｕ－１５－ｅｎ－１７－ｏｌ，ｅｎｔ－ｋａｕｒａｎ－１６β，１７－ｄｉｏｌ，ｅｎｔ－ｋａｕｒａｎ－１６ α，１７－ｄｉｏｌ。晶Ⅳ Ｃ_(２２)Ｈ_(３６)Ｏ_(４)，ｍｐ １６３℃～１６４℃，经波谱分析及降解反应，鉴定其结构为 ｅｎｔ－３β-ａｃｅｔｏｘｙ－ｋａｕｒａｎ－１６ β， １７－ｄｉｏｌ，命名为鄂贝醇（ｆｒｉｔｉｌｌｅ－ｂｅｉｎｏｌ）， Ⅰ～Ⅲ在该植物中系首次分得。Ⅳ系首次发现的新天然产物。晶 Ⅴ和晶Ⅵ为聚合二萜，其结构正在鉴定中。

The bulb of Fritillaria ebeiensis G. D. Yu et G. Q. Ji is commercially available as a substitute for the principal Chinese traditional medicine' Beimu '. As for the non basic constituents of the bulbs of this plant, we have isolated and identified fritillebic acid and three diterpenoid dimers, i. g. fritillebin A, fritillebin B and fritillebinide C in a previous study. In continuation of our investigation of non basic constituents, six ent-kaurane diterpenoids (Ⅰ~Ⅵ) were further isolated from the bulb of F. ebeiensis cultivated in Suizhou district, Hubei. Compounds Ⅰ~Ⅲ were identified as the known diterpenoids ent-kan--15--en-17-ol, ent-kauran--16β 17-diol and ent--kauran-16a, 17--diol on the basis of spectral data TLC and mixed mp comparison with authentic samples, and references. Compound Ⅳ, C_(22),H_(36)O_(4), mp 163 ~ 164 ℃, named fritillebinol, is a new diterpenoid, its structure has been established as ent-3β-acetoxy-kauran-16β, 17-diol on the basis of its spectroscopic and chemical evidences. Compounds Ⅴ and Ⅵ are diterpenoid dimers, their structures are still under investigation.