Voacangine

Voacangine (12 methoxyibogamine 18 carboxylic acid methyl ester) is an alkaloid found predominantly in the root bark of the Voacanga africana tree, as well as in other plants such as Tabernanthe iboga, Tabernaemontana africana, Trachelospermum jasminoides, Tabernaemontana divaricata and Ervatamia yunnanensis. It is an iboga alkaloid which commonly serves as a precursor for the semi synthesis of ibogaine. It has been demonstrated in animals to have similar anti addictive properties to ibogaine itself. It also potentiates the effects of barbiturates. Under UV A and UV B light its crystals fluoresce blue green, and it is soluble in ethanol.

Voacangine exhibits AChE inhibitory activity. Docking simulation reveals that it has inhibitory effect on VEGF2 kinase and reduces angiogenesis. Like ibogaine, its a potent HERG blocker in vitro. It also acts as antagonist to TRPM8 and TRPV1 receptor, but agonist of TRPA1.

The absolute bioavailability of voacangine is around 11–13%.

The late stage biosynthesis of ( ) voacangine in Tabernanthe iboga, a ( ) ibogamine type alkaloid, has been elucidated via homology guided transcriptome mining. Suspected RNA transcripts involved in ( ) voacangine biosynthesis were identified via sequence homology to previously described enzymes comprising the (+) catharanthine biosynthesis, a (+) ibogamine type alkaloid from the taxonomically related plant Catharanthus roseus. Ibogamine type alkaloids are biosynthesized from the late stage intermediate stemmadenine acetate, a strictosidine derived biosynthetic intermediate for a wide number of plant natural products. The biosynthesis of stemmadenine acetate has been characterized in C. roseus to form ( ) voacangine (7).