Les alcaloïdes des fruits et des feuilles du Strychnos usambarensis

Fruits of Strychnos usambarensis may be cause of poisoning in Africa. The main alkaloid of an extract with CHCl3 at pH 5 has been isolated and identified as descarbomethoxydihydrogambirtannine; that alkaloid is found for the first time in the family of Loganiaceae.The structure of usambaridine Vi, alkaloid previously isolated from leaves, is now elucidated by analysis of NMR and UV spectra. Its structure corresponds to 10-hydroxy-usambarine.