Abstract: Ludongnin, a new spirosecokaurene diterpenoid was isolated from Rabdosia rubescens (Hemsl.) Hara colleeted in Lushi, Henan. The structure was estab- lished from its spectral and chemical evidence. It is the first instance of an ent- kaurene type diterpenoid possessing a γ-lactonic ring in between C6-C19, while all the other known type diterpenoids isolated from Rabdosia species are not γ-lactonic ring in between C6--C19.

Key words: structure, ludongnin

摘要： 冬凌草[Rabdosia rubescens(Hemsl.)Hara]为唇形科香茶菜属植物，是近年来河南省从民间发掘出来的一种具有对多种动物移植性肿瘤有一定的抗肿瘤作用，对食管癌、肝癌以及扁挑体炎、咽喉炎、口腔炎等有一定疗效的植物药。对河南省济源县产的冬凌草，其化学成份已进行了研究，从中分离鉴定了四个对映-贝壳杉烯型(ent－Kaurene type)二萜化合物，分别命名为冬凌草甲素(rubescenin A=oridonin),乙素(rubescensin B=ponicidin),丙素(rubescensin C)，和丁素(rubescensin D)，其中丙素，丁素为新化合物，但其生理活性成分为甲素和乙素。

关键词: 卢氏, 冬凌草素, 结构