Abstract: Rabdosia rubescens Hara var.lushiensis Gao et Li (labiatae )which is widely distributed in theFuniushan west area of Henan,had BEEN used for the treatment of esphagel and cardial carcinoma in Henan.We have reported the isolation and the structural determination of ludongnin A from the ethereal extract of the dry leaves of this plant.The present paper, we report studies on a new crystalline diterpenoid, ditrpenoid, ludongnin B[C 20 H 26 O 5 ,MP 296-9.C]which is a minor component isolated from the same plant and its structure has been shown to be ent-6,7-spirosece-7,20-δ-lactonic ring- 6, 19-γ-lactonic ring-16-kaurane-15-one (1)on the basis of spectrodcopic evidence and compared with fnown compound, ludongini A.

Key words: Diterpenoid