Biosynthesis of amaranthin in Celosia plumosa

Seedlings of a yellow betaxanthin-producing variety of Celosia plumosa when fed with appropriate precursors are capable of synthesizing the red-violet pigment normally present in red varieties of the same species, namely amaranthin. Synthesis of amaranthin occurs in seedlings following administration of betanidin and betanin but much greater accumulation was observed after feeding cycloDOPA and its 5-O-β-d-glucoside. Possible pathways in the biosynthesis of amaranthin are discussed.