[Studies on the indole alkaloids of Winchia calophylla A. DC]

Winchia calophylla A. DC. (Apocynaceac) is one traditional medicine of the Dai Nationality in Xishuangbanna, Yunnan Province, for the treatment of trachitis. Four indole alkaloids have been isolated from the stem bark and the leaves of this plant by aluminum oxide and silica gel chromatography. Three of them were identified as echitamine chloide (I), echitamidine (II) and Nb-demethyl-echitamine (III) by comparison with literature. One of them are new, with structures elucidated as 22-O-acetyl-Nb-demethyl-echitamine (IV) by chemical and spectroscopic methods.