Metabolism, Disposition, Excretion, and Potential Transporter Inhibition of 7–16, an Improving 5-HT_2A Receptor Antagonist and Inverse Agonist for Parkinson’s Disease

Compound 7–16 was designed and synthesized in our previous study and was identified as a more potential selective 5-HT2A receptor antagonist and inverse agonist for treating Parkinson’s disease psychosis (PDP). Then, the metabolism, disposition, and excretion properties of 7–16 and its potential inhibition on transporters were investigated in this study to highlight advancements in the understanding of its therapeutic mechanisms. The results indicate that a total of 10 metabolites of 7–16/[14C]7–16 were identified and determined in five species of liver microsomes and in rats using UPLC-Q Exactive high-resolution mass spectrometry combined with radioanalysis. Metabolites formed in human liver microsomes could be covered by animal species. 7–16 is mainly metabolized through mono-oxidation (M470-2) and N-demethylation (M440), and the CYP3A4 isozyme was responsible for both metabolic reactions. Based on the excretion data in bile and urine, the absorption rate of 7–16 was at least 74.7%. 7–16 had weak inhibition on P-glycoprotein and no effect on the transport activity of OATP1B1, OATP1B3, OAT1, OAT3, and OCT2 transporters. The comprehensive pharmacokinetic properties indicate that 7–16 deserves further development as a new treatment drug for PDP.