flavan / flavin / flavine [ˈfleivɪn]
flavan – n – Biochemistry 2-Phenylbenzopyran (C15H14O), an aromatic heterocyclic compound from which all flavonoids are derived
flavin – n. – 1. the chemical compound forming the nucleus of various natural yellow pigments; 2. a yellow dye formerly obtained from dyer’s oak.
flavine – n. – an antiseptic derived from acridine (a colorless crystalline feebly basic tricyclic compound C13H9N occurring in crude anthracene fractions from coal tar and important as the parent compound of dyes and pharmaceuticals (as acriflavine and quinacrine))