Deserpidine (Harmonyl) is only found in individuals that have used or taken this drug. It is an ester alkaloid drug isolated from Rauwolfia canescens (family Apocynaceae) with antipsychotic and antihypertensive properties that has been used for the control of high blood pressure and for the relief of psychotic behavior.Deserpidine's mechanism of action is through inhibition of the ATP/Mg2+ pump responsible for the sequestering of neurotransmitters into storage vesicles located in the presynaptic neuron. Deserpidine is a competitive angiotensin converting enzyme (ACE) inhibitor. Deserpidine also decreases angiotensin II-induced aldosterone secretion by the adrenal cortex.