» For the town in France, see Flavin, Aveyron. Flavin (from Latin flavus, "yellow")'s the common name for a group of organic compounds based on pteridine, formed by the tricyclic heteronuclear organic ring isoalloxazine. The biochemical source's the vitamin riboflavin. The flavin moiety's often attached with an adenosine diphosphate to form flavin adenine dinucleotide (FAD), and, in other circumstances,'s found as flavin mononucleotide (or FMN), a phosphorylated form of riboflavin. It's in one… (More on Fadh)