Ajmalicine, also known as δ-yohimbine or raubasine, is an antihypertensive drug used in the treatment of high blood pressure. It has been marketed under numerous brand names including Card-Lamuran, Circolene, Cristanyl, Duxil, Duxor, Hydroxysarpon, Iskedyl, Isosarpan, Isquebral, Lamuran, Melanex, Raunatin, Saltucin Co, Salvalion, and Sarpan. It is also an alkaloid found naturally in various plants such as Rauwolfia spp., Catharanthus roseus, and Mitragyna speciosa.
Ajmalicine is structurally related to yohimbine, rauwolscine, and other yohimban derivatives. Like corynanthine, it acts as a α1-adrenergic receptor antagonist with preferential actions over α2-adrenergic receptors, underlying its hypotensive rather than hypertensive effects.