Aspects of secondary metabolism in basidiomycetes: I. biological and biochemical studies on Psilocybe cubensis II. a survey of phenol-o-methyltransferase in species of Lentinus and Lentinellus

Psilocybe cubensis produced psilocybin only when first grown on Sabouraud agar before transfer to liquid media. Maximal psilocybin production occurred on the fifth day. An acid phosphatase from mycelia grown in one medium showed very high activity, producing a blue color from oxidized psilocin within five minutes. Adding L-tryptophan significantly stimulated early psilocybin production in one medium; tryptophan was degraded to kynurenine and anthranilic acid in the other medium and to tryptamine in the tryptophan-supplemented medium. Radioactive tryptophan labeled psilocin and psilocybin. Potassium deficiency decreased psilocybin production. Psilocin showed slight antibiotic activity against Candida albicans; psilocybin had none. Among eight Lentinus and Lentinellus species, only Lentinus lepideus and Lentinus phonderbsus showed phenol-O-methyltransferase activity, using methyl p-coumarate, methyl caffeate, and methyl ferulate as substrates.

Study at a glance

Abstract

I. Psilocybe cubensis was cultured successfully in two media. Medium A was devised by Catalfomo and Tyler and Medium B was a modification of a medium which has been used for ergot alkaloid production by Claviceps purpurea. Only when the fungus was kept on Sabouraud agar plates.did it subsequently produce psilocybin when transferred to liquid media. A quantitative time-course study of psilocybin production in the two media was carried out. Maximal production appeared on the fifth day. The activities of an acid phosphatase, acting on psilocybin, were measured from mycelia grown in the two media. Enzyme activity from the A culture was very high and a blue color caused by oxidation of psilocin formed in five minutes. The effect of adding L-tryptophan on alkaloid production as well as the fate of tryptophan-C¹⁴ was also investigated. Tryptophan stimulated significantly psilocybin production in the very beginning in the B medium. The degradation of tryptophan was different in the two media. It was converted to kynurenine and anthranilic acid in A medium and to tryptamine in tryptophan added B medium (B' medium). Radioactive D,L-tryptophan side chain labeled, gave labeled psilocin and psilocybin. Potassium deficiency decreased psilocybin production while a potassium supplement had no effect. The fungus did not produce polyacetylenic compounds in the medium but ergosterol was detected as a major acetate derived metabolite when the fungus was kept on MYP agar plates and transferred subsequently to liquid media. Psilocin has very slight antibiotic activity against Candida albicans whereas psilocybin has none. II. Eight species of Lentinus and Lentinellus were investigated for the occurrence of a phenol-O-methyltransferase. Only Lentinus lepideus and Lentinus pbnderbsus showed enzyme activity in both light and dark conditions. The specificity of the enzyme for a number of substrates was also examined. Of six compounds tested, methyl p-coumarate, methyl caffeate and methyl ferulate.served-as substrates. The products of enzymic activity were identified-by radioautography.