Biosynthetic origin of alkylated decaline-type polyketides and induction of a new metabolite by addition of benzoate in cultured mycobionts of Pyrenula sp.

Abstract

The assembly pattern of acetate units and methyl groups in the biosynthesis of a polyketide, pyrenulic acid C (1), in cultured mycobionts of a Vietnamese Pyrenula sp. was verified by administration of sodium [1-13C]-acetate, sodium [1,2-13C2]-acetate, and L-[methyl-13C]-methionine. The cultured mycobionts were induced to produce a new polyketide, pyrenulic acid I (2), by addition of sodium benzoate to malt-yeast extract medium supplemented with 5% sucrose. Its structure was determined by spectroscopic methods.