Biosynthesis of auranthine by Penicillium aurantiogriseum

Abstract

14C-labelled anthranilic acid administered to Penicillium aurantiogriseum in stationary liquid culture was incorporated with a mean efficiency of 0.3% into the novel benzodiazepine metabolite auranthine. Incorporation of radioactivity from 14C-labelled glutamine, glutamate and ornithine was 0.08%, 0.06% and 0.03% respectively, consistent with the biosynthesis of auranthine, involving the condensation of two molecules of anthranilate with one molecule of glutamine. The use of anthranilic acid radiolabelled in the carbonyl carbon is an effective probe for detecting novel fungal secondary metabolites, the structure of which contains a benzodiazepine moiety.