Tabernanthine

BeschreibungAn alkaloid which occurs in Tabernanthe iboga BailI. and also in Stem madenia donnell-smithii R. E. Woodson, this base was first given the formula C21H2SON2, later altered to that given above. The alkaloid forms colourless needles or orthorhombic plates from EtOH and is best purified by sublimation. It has [α]D - 35° and gives an ultraviolet spectrum with absorption maxima at 229, 271 and 299 IIlfJ.. The hydrochloride forms colourless crystals from boiling H20, m.p. 275-7°C; [α]25.5D - 66° (MeOH). This salt is freely soluble in CHCI3, contains one methoxyl group and is unsaturated.When injected intravenously into dogs, the alkaloid is hypotensive, reduces the reflex hypertension induced by occlusion of the carotids, decreases both the rate and amplitude of respiration and, like Ibogaine (q.v.), increases the hypertension produced by injection of adrenaline. It has also been found to prolong the hypotension which results from the injection of acetylcholine.