The Chemistry of Fungal Metabolites

The major chemical constituents of the mould, Lenzites striata, have been separated chromatographically. From the broth have been isolated three isocoumarins, cospolactone oosponol, and oospoglycol, known metabolites of another microorganism: an investigation of the biosynthesis of oospoglycol has shown that it is acetate derived. The metabolites of the mycelium of L.striata have also been examined and shown to be acetyldehydroeburicoic acid, eburicoic acid and sulphurenic acid: a fourth triterpene metabolite of novel structure has been isolated and named "lenzitic acid." The structures of two metabolites previously isolated from Daedalea quercina and Leptoporus stipticus have been revised and characterised as Delta'-pyrazoline derivatives. Several synthetic approaches to the ortho-terphenyl system have been investigated and the compounds thus prepared examined in the n.m.r. spectrometer: these results have assisted the elucidation of the structures of two related metabolites previously isolated from Aspergillus candidus, and shown to possess anti-keratinophilic activity. Nuclear Overhauser studies on both the model compounds and natural products have also been used in structure assignment