Delequamine (; developmental code names RS-15385, RS-15385-197) is a potent and selective ñ<sub>2</sub>-adrenergic receptor antagonist which was under development for the treatment of erectile dysfunction and major depressive disorder but was never marketed.
It is structurally related to the naturally occurring ñ<sub>2</sub>-adrenergic receptor antagonist yohimbine but has greater selectivity in comparison. The drug has been found to affect sexual function and sleep in humans.
Delequamine reached phase 3 clinical trials prior to the discontinuation of its development. The drug was under development in the 1990s and its development was discontinued by 1999. It was first described in the scientific literature by 1990.