Abstract: Rabdosia rubescens Hara f. lushanensis Gao et Li which has been used for the treatment of esphagel and cardial carcinoma in Henan.We have repor- ted the isolation and the structural determination of lushanrubescensin A, B, C and D from the dry leaves of this plant collected in Lushan, Henan. In the pre- sent paper,we report studies on a new crystalline diterpenoid, lushanrubescensin E [C24.H34O7, mp 215-217 .5℃, [ α]D19- 77.5° isolated from the ether extract of the leaves of same plant. Lushanrubescensin E is another active principle for the treatment of esphagel and cardial carcinoma and its structure has been shown to be ent-2a, 11 β-dihydroxy-3α 6β-diacetoxy-16-kauren-15-on (1 ) from spec- troscopic and chemical cyidcnces, as well as from comparisoil its data with that of known coJnpounds, lusllanrubescensin A, B, C and D. Based on the preliminary antineoplastic activity test, (1 ) show a significant cytotoxicity against Ehrlich carcinoma ccll in vitro. The results will be published elsewhere.

Key words: Diterpeno d