The Biosynthesis of Spinulosin in Aspergillus fumigatus.

Abstract

3,4-Dihydroxy-2,5-toluquinone, 3-methoxy-4-hydroxy-2,5-toluquinone, and fumigatin are identified as metabolic products of A. fumigatus, L.S.H.T.M. No. A 49, which is known also to produce spinulosin. The acetate-malonate origin of fumigatin from A. fumigatus, L.S.H.T.M. No. A 46, is shown by degradation of labelled fumigatin obtained after feeding the mould with 2-Cl4-malonate. Fumigatin hydroquinone is proved to be an intermediate in the biosynthesis of spinulosin in strain A 49 by the use of fumigatin, specifically C14-labelled by biosynthesis from 2-C14-malonate or C14H3-L-methionine. A simple technique to show the incorporation, as a unit, of a non-specifically labelled precursor is described and used to prove that fumigatin hydroquinone is a precursor of spinulosin also in strain A 46.