紫花鄂北贝母含氯元素二萜成分的结构

Structure of a New Chloro-substituded Diterpenoid, Fritillaziebinol from Zihua

从紫花鄂北贝母 Ｆｒｉｔｉｌｌａｒｉａ ｅｂｅｉｅｎｓｉｓ ｖａｒ． ｐｕｒｐｕｒｅａ Ｇ． Ｄ． Ｙｕ ｅｔ Ｐ． Ｌｉ 磷茎非生物碱部分中分离到４种 ｅｎｔ－ｋａｕｒａｎｅ骨架的二萜。晶ＩＣ_(２０)Ｈ_(３３)ＯＣｌ，ｍｐ１５３℃～１５４℃，经波谱分析鉴定其结构为ｅｎｔ－ｋａｕｒａｎ－１６β-ｈｙｄｒｏｘｙ－１７－ｃｈｌｏｒｉｄｅ，命名为鄂见新醇（ｆｒｉｔｉｌｌａｚｉｅｂｉｎｏｌ）。晶 Ⅱ、Ⅲ和 Ⅳ经波谱解析及与标准品对照，分别鉴定为ｅｎｔ－ｋａｕｒａｎ－１６β，１７－ｄｉｏｌ，ｅｎｔ-ｋａｕｒａｎ－３β，１６β，１７－ｔｒｉｏｌ，ｅｎｔ－３β-ａｃｅｔｏｘｙ－ｋａｕｒａｎ－１６β，１７－ｄｉｏｌ，Ⅰ系新的天然含氯二萜， Ⅱ～Ⅳ在该植物中首次得到。

The bulb of Fritillaria ebeiensis var. purpurea G. D. Yu et P. Li is a liliaceous plant growing in the Suizhou district of Hubei province, China. This Plant, easily cultivable in the district, has high alkaloid content and shows conspicuous antitussive and expectorant effects. The bulbs treated with lime and then bleached in the sun, are called 'Ebeibeimu', and are commercially available as a substitute for the principal Chinese traditional medicine 'Beimu'. With regard to the alkaloid constituents of the bulbs, we have already reported the presence of six C-nor-D-homo steroidal alkaloids, but the non basic constituents have not been reported. In our continuing studies on its chemical constituents, a novel ent-kaurane diterpenoid with chloro-substituded C-17 fritillaziebinol (1) was isolated with three known diterpenoids, Ⅱ,Ⅲ and Ⅳ from bulbs of Fritillaria ebeiensis var. purpurea G. D. Yu et P. Li. The compounds Ⅲ-Ⅳ have been identified as the known diterpenoids ent-kauran-16β, 17-diol, ent-kauran-3β, 16β, 17-triol, and ent-3β-acetoxy-kauran- 16β, 17-diol on the basis of spectral data, TLC and mixed mp comparison with authentic samples. Compound I, C_(20)H_(33)OCl, mp 153℃-154℃, named fritillaziebinol, is a new ent-kauran diterpenoid with chloro- substituded C-17 has been established as ent-kauran-16β-hydroxy-17-chlorid on the basis of spectral methods including 2D-NMR techniques