Entacapone is a potent and specific peripheral catechol-O-methyltransferase (COMT) inhibitor with an IC50 of 151 nM. Entacapone is also a potential obesity-related gene (FTO) inhibitor that can inhibit FTO demethylation activity and be used in the study of metabolic diseases.

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.

Hydroxyamine hydrochloride(Hydroxylammonium chloride) is a selective and potent monoamine oxidase (MAO) inhibitor with inhibitory effects on platelet aggregation.Hydroxyamine hydrochloridee is an intermediate in organic synthesis and can be used to synthesize other active compounds.

Paeonol (Peonol) is an active extraction from Paeonia suffruticosa. Paeonol inhibits MAO-A and MAO-B with IC50 of 54.6 μM and 42.5 μM, respectively.