Alkaloids from Tabernaemontana psorocarpa.

The isolation of the alkaloids from two different samples of stem bark of Tabernaemontana psorocarpa is described. Both samples contained 16-epi-isositsirikine as the major alkaloid but differed from each other in the number and quantity of the other alkaloids. The following minor alkaloids were identified: 12-methoxy-14,15-dehydro-vincamine, vallesiachotamine, isovallesiachotamine, tetrahydroalstonine, coronaridine and voacangine.