Tabernaemontanine

Tabernaemontanine is a naturally occurring monoterpene indole alkaloid found in several species in the genus Tabernaemontana including Tabernaemontana divaricata.

History
Tabernaemontanine was first reported in 1939 but its structure was only fully confirmed in the 1970s as there was confusion in the original literature regarding the configuration of the ethyl group in the piperidine ring of this alkaloid and its isomer dregamine, so that their identities had been reversed. Both compounds were isolated from plants of the dogbane (Apocynaceae) family including Tabernaemontana coronaria. They have structures that are reduced versions of vobasine.

Biosynthesis
As with other Indole alkaloids, the biosynthesis of tabernaemontanine starts from the amino acid tryptophan. This is converted into strictosidine before further elaboration.

Natural occurrence
Tabernaemontanine is found commonly in the genera Tabernaemontana and Kopsia, including the species Ervatamia hirta, Tabernaemontana elegans and Tabernaemontana divaricata. The latter species is known to produce many other alkaloids including catharanthine, ibogamine and voacristine.

Research
Plant metabolites have been of interest for their possible biological activity and alkaloids in particular are major subjects for ethnobotanical research. Tabernaemontanine has been studied, for example as a potential anti-cancer agent,  for its antimalarial activity  and in antifertility research. However, the alkaloid itself has not been developed as a drug.