Essential hepatic enzyme that catalyzes the oxygenation of a wide variety of nitrogen- and sulfur-containing compounds including drugs as well as dietary compounds (PubMed:10759686, PubMed:30381441). Plays an important role in the metabolism of trimethylamine (TMA), via the production of trimethylamine N-oxide (TMAO) metabolite (PubMed:9776311). TMA is generated by the action of gut microbiota using dietary precursors such as choline, choline containing compounds, betaine or L-carnitine. By regulating TMAO concentration, FMO3 directly impacts both platelet responsiveness and rate of thrombus formation (PubMed:29981269). H(+) + N,N-dimethylaniline + NADPH + O2 = H2O + N,N-dimethylaniline N-oxide + NADP(+) NADPH + O2 + trimethylamine = H2O + NADP(+) + trimethylamine N-oxide fenbendazole + O2 + reduced [NADPH--hemoprotein reductase] = fenbendazole S-oxide + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] albendazole + O2 + reduced [NADPH--hemoprotein reductase] = albendazole S-oxide + H(+) + H2O + oxidized [NADPH--hemoprotein reductase] (S)-nicotine + NADPH + O2 = H2O + NADP(+) + trans-(S)-nicotine N(1')-oxide Liver. The disease is caused by variants affecting the gene represented in this entry. Belongs to the FMO family. A case for discomfort - Issue 149 of June 2013