Melanin biosynthesis: a study of polyphenol deoxygenation

Abstract

The 1,3,6,8-tetrahydroxynaphthalene (T₄HN) reductase of Verticillium dahliae has been studied in a cell-free system. The use of specifically labelled 4(R)- and [4(S)-²H] NADPH in the reduction of T₄HN to scytalone reveals that the label is specifically transferred in the case of [4(S)-²H] NADPH whereas no deuterium transfer occurs with the 4R-isomer. This establishes that the T₄HN reductase of V. dahliae is a NADPH-dependent dehydrogenase and that it belongs to class B.