Avanafil metaboliteM4 is a major active metabolite of the phosphodiesterase 5 (PDE5) inhibitor avanafil . Avanafil is metabolized by the cytochrome P450 (CYP450) isoforms CYP3A4 and CYP2C to the major metabolites avanafil metaboliteM4 and avanafil metabolite M16 , as well as minor metabolites. Avanafil metaboliteM4 inhibits PDE5 with 18% of the potency of avanafil.
Deutetrabenazine metaboliteM4 is believed to be related to its effect as a reversible depletion of monoamines from nerve terminals. The major circulating metabolites of Deutetrabenazine, are reversible inhibitors of VMAT2, resulting in decreased uptake
Imidafenacin metaboliteM4 is a metabolite of the muscarinic acetylcholine receptor antagonist imidafenacin.1It is formed from imidafenacin by the cytochrome P450 (CYP) isoform CYP3A4. 1.Kanayama, N., Kanari, C., Masuda, Y., et al.Drug-drug interactions in the metabolism of imidafenacin: Role of the human cytochrome P450 enzymes and UDP-glucuronic acid transferases, and potential of imidafenacin to inhibit human cytochrome P450 enzymesXenobiotica37(2)139-154(2007)
Lopinavir Metabolite M-1, an active metabolite derived from Lopinavir, effectively inhibits the HIV protease enzyme with a Ki value of 0.7 pM. Additionally, in vitro studies have revealed notable antiviral properties associated with Lopinavir Metabolite M-1.
Ramelteon metabolite M-II is the primary metabolite of Ramelteon and exhibits IC50 values of 208 pM and 1470 pM for human melatonin receptors (MT1 and MT2), respectively. Ramelteon itself is a selective melatonin receptor agonist.