Abstract: Winchia calophylla A.DC.(Apocynaceae) as a traditional medicinal plant is mainly distributed in Yunnan and Hainan Province of China,India,Myanmar and Indonesia.The stem barks were used for the treatment of chronic tracheits in Dai Nationality in Xishuangbanna,Yunnan Province of China.In order to find the compounds with good biological activity,the chemical constituents research of the twigs of the titled plant was presented in this paper.Four monoterpenoid indole alkaloids were isolated from the methanol extracts.They were identified as echitamidine,17-O-acetyl-N-b-demethylechitamine, N-b-demethylechitamine,and N-b-demethylechitamine -N-oxide by using the spectroscopic technique and comparing with the literatures.

Key words: Apocynaceae, Winchia calophylla;chemical constituents;monoterpenoid indole alkaloid