Rabdosia species

Recent Advances in the Chemistry of Diterpenoids from Rabdosia species... 

The first investigation of the bitter principles in enmei-so was carried out in 1910 and isolation of a crystalline bitter substance was reported by Yagi (2). In 1954, antibacterial activity was reported for the extract (5). In 1958, isolation of enmein, one of the major diterpenoid constituents, initiated structure determination and investigation of other constituents. Since then, our knowledge of the diterpenoids of Rabdosia species has developed to a remarkable degree. Particular interest has centered on their antitumor activity. For previous reviews of the chemistry of Rabdosia diterpenoids, the reader is referred to Ref. (4—7). 

Table V lists those Rabdosia species which have been investigated in alphabetical order and the diterpenoids isolated from each species.

In Japan, R.japonica and R. trichocarpa have been used as bitter stomachics and anthelminthics, while in China R. ternifolia has been used as an antiphlogistic, germicide, antipyretic, and toxicide and R, rubescens is used in cancer of the esophagus. Initial studies to track down the compounds responsible for the activity of Rabdosia species were carried out in 1954. Subsequent studies dealt with cytotoxicity, antitumor activity, inhibition of oxidative phosphorylation, anti-feeding activity, growth inhibitory activity, and bitterness. All of the foregoing activities have been attributed to the diterpenoid constituents. 

Contents O. Tanaka and R. Kasai Saponins of Ginseng and Related Plants. — E. Fujita and M. Node Diterpenoids of Rabdosia Species. — S.Johne The Quinazoline Alkaloids. 

Fujita E, Node M (1984) Diterpenoids of rabdosia species. Prog Chem Org Nat Prod 46 77-157... 

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