yohimbine

An alkaloid, C₂₁H₂₆N₂O₃, that is derived from the bark of a tree, Pausinystalia johimbe, and is an alpha-blocker drug used in the form of its hydrochloride as a mydriatic, a treatment for erectile dysfunction, and formerly as an aphrodisiac.

A colorless dextrorotatory alkaloid, C₂₃A₃₂O₄N₂, found, together with yohimbenine, in the bark and leaves of the yohimbé or yumbehoa-tree, belonging to the Rubiaceæ. It crystallizes in needles and melts at 234° C.

A tryptamine alkaloid, the active chemical constituent of the medicinal herb Pausinystalia yohimbe: a stimulant and supposed aphrodisiac.