Rauwolscine is an alkaloid found in various species within the genera Rauwolfia and Pausinystalia (formerly known as Corynanthe). It is a stereoisomer of yohimbine. Rauwolscine is a central nervous system stimulant, a local anesthetic and a vague aphrodisiac.Rauwolscine acts predominantly as a α2-adrenergic receptor antagonist. It has also been shown to function as a 5-HT1A receptor partial agonist and 5-HT2A and 5-HT2B receptor antagonist. Rauwolscine: an antagonist radioligand for the cloned human 5-hydroxytryptamine2b (5-HT2B) receptor. [3H]5-HT has been used to characterize the pharmacology of the rat and human 5-HT2B receptors. 5-HT, the native agonist for the 5-HT2B receptor, has a limitation in its usefulness as a radioligand since it is difficult to study the agonist low-affinity state of a G protein-coupled receptor using an agonist radioligand.