Violacein is a member of the class of hydroxyindoles resulting from the formal oxidative coupling between the 3-position of 1,3-dihydro-2H-indol-2-one and the 3-position of 1,3-dihydro-2H-pyrrol-2-one, which is substituted at the 5 position by a 5-hydroxy-1H-indol-3-yl group, where the newly-formed double bond has E configuration. It is a purple chromobacterial pigment that has antibacterial, antifungal, antiprotozoan, and anticancer properties. It has a role as an antibacterial agent, an antineoplastic agent, an antifungal agent, an apoptosis inducer and a bacterial metabolite. It is a member of pyrroles, a member of oxindoles, an olefinic compound and a member of hydroxyindoles. It is functionally related to a proviolacein.