Contribution à l'étude des alcaloïdes du Strychnos usambarensis

Strychnos usambarensis is concerned with the preparation of an arrow poison used in Africa for hunting. By chromatography combined to a new process of extraction using freeze-drying to avoid the degradation of some unstable alkaloids in usual industrial solvents ( chloroform, diethylether), we have isolated four new alkaloids (usambarensine and derivatives) from the rootbark of S. usambarensis. These alkaloids have structures very close to some found in Apocynaceae and Rubiaceae.