Alkaloids of Tabernaemontana eglandulosa

From the leaves and twigs of Tabernaemontana eglandulosa 22 alkaloids, of which 12 are new, have been isolated. Besides tacamine (pseudo-vincamine) 7 other alkaloids of this new class of indole alkaloids were identified. A further three alkaloids of the cleavamine type, namely the known ( + )20R-15, 20-dihydro-cleavamine and (-)20S-15, 20-dihydro-cleavamine and one new alkaloid, which was tentatively identified as 14S, 20R-velbanamine, two new alkaloids of the pseudo-aspidospermidine type, namely 20R-l,2-dehydro-pseudo-aspidospermidine and 20S-hydroxy-l,2-dehydro-pseudoaspidospermidine and an alkaloid of a novel iboga type were isolated. More common alkaloids isolated were coronaridine, 11-hydroxycoronaridine, voaphylline, tubotaiwine, ibogamine, norfluorocurarine and probably a mixture of 20R- and 20S-pseudo-vincadifformine. Only quantitative differences in the alkaloid content of the leaves, twigs and stembark were observed.