Isocyasterone is an insect metamorphosing substance, which can be isolated from Cyathula capitata.

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.

A purine base found in most body tissues and fluids, certain plants, and some urinary calculi.