Purpurin (Verantin) was a reversible and competitive inhibitor of MAO-A with a Ki value of 0.422μM. it exhibits anti-angiogenic, antifungal, antibiotic, and antioxidative activities.

Hydralazine hydrochloride (Apresoline) is the hydrochloride salt of hydralazine, a phthalazine derivative with antihypertensive and potential antineoplastic activities. Hydralazine alters intracellular calcium release and interferes with smooth muscle cell calcium influx, resulting in arterial vasodilatation. This agent also inhibits the phosphorylation of myosin protein and chelation of trace metals required for smooth muscle contraction, resulting in an increase in heart rate, stroke volume, and cardiac output. In addition to its cardiovascular effects, hydralazine inhibits DNA methyltransferase, which may result in inhibition of DNA methylation in tumor cells.

Tranylcypromine (2-PCPA) hydrochloride (SKF-385 HCl), a Monoamine Oxidase inhibitor, is effective in the treatment of major depression, dysthymic disorder, and atypical depression.

(Z)-SU4312 is a inhibitor of MAO-B and NOS(IC50 value of 0.2 μM, 19.0μM,respectively).

PF-9601N showed high potency and selectivity as a MAO-BI (monoamine oxidase type B inhibitor) and also demonstrated remarkable neuroprotective properties in several in vivo and cellular models of PD.