N-methylnicotinamide is a metabolite of niacin (or nicotinamide) and is commonly found in human urine. However low levels of urinary excretion of N-methylnicotinamide indicates niacin deficiency. In patients with liver cirrhosis nicotinamide methylation is increased leading to a rise in urinary N-methylnicotinamide. N-methylnicotinamide has been found to be a microbial metabolite.

Harmane (harman) is a bio-active β-Carboline and monoamine oxidase inhibitor found in coffee and tobacco smoke.

HET0016 is a potent and selective 20-HETE synthase inhibitor (IC50s: 17.7 nM, 12.1 nM, and 20.6 nM for recombinant CYP4A1-, CYP4A2-, and CYP4A3-catalyzed 20-HETE synthesis) and a selective CYP450 inhibitor, shown to inhibit angiogenesis and tumor growth.