Isolation and characterization of adenochrome, a unique iron(III)-binding peptide from Octopus vulgaris

Abstract
Adenochrome, the iron(III)-containing pigment from the branchial heart of Octopus vulgaris, has been isolated as colourless desferri-adenochrome (DFA) and shown to consist of a mixture of closely related peptides derived from glycine and three isomeric amino-acids, adenochromines A, B, and C, which were formulated as the novel dopa derivatives (1a), (1b), and (1c), respectively, by spectral and chemical evidence.