Studies on the biosynthesis of phenols in fungi. Production of 4-methoxytoluquinol, epoxysuccinic acid and a diacetylenic alcohol by surface cultures of Letinus degener I.M.I. 110 525.

1. 4-Methoxytoluquinol was secreted into the medium by surface cultures of the basidiomycete Lentinus degener Kalchbr. (approx. 100mg./l. of medium). In addition, epoxysuccinic acid (150-200mg.) and a long-chain diacetylenic alcohol (3mg.) were also secreted. Epoxysuccinic acid has previously been found in the culture medium of some Fungi Imperfecti. These metabolites were all synthesized during the early phase of growth but maximum production occurred some time later. 2. Supplementation of the medium with cycloheximide or 8-azaguanine inhibited the production of epoxysuccinic acid. 3. Sodium [1-(14)C]acetate and 6-methyl[(14)C]salicylic acid were not incorporated into 4-methoxytoluquinol, but [U-(14)C]tyrosine and [Me-(14)C]methionine were incorporated to the extent of 0.55 and 4.75% respectively (minimum values). Degradation studies established that the aromatic ring and C-methyl group were derived from the ring and beta-carbon atom of tyrosine; the O-methyl group alone was formed from methionine.