Abstract: During the course of our studies on the biologically active constitucnts of Rabdosia plants, we examined the ether extract of thr leaves of Rabdosia rubescens (Hemsl .) Hara collecled in Lushan, Henan. A new diterpenoid, Jushanrubescensin (1 ) was isolated together with α-amyrin and ursolic acid. On the basis of spectroscopic and chemical evidence, the structure of (1 ) has been established as ent-7β-hydroxy-2α,3α,6β, 11β-fetraacetoxy-16-kauren-15-one.

Key words: structure, lushanrubesensin