Studies in the biochemistry of micro-organisms. 115. Metabolites of Penicillium frequentans Westling: isolation of sulochrin, asterric acid, (+)-bisdechlorogeodin and two new substituted anthraquinones, questin and questinol

The mould Penicillium frequentans Westling is, as its name implies, of very common occurrence on all kinds of material. According to Raper & Thom (1949), the Monoverticillate section of the genus Penicillium includes a P. frequentans series of three species, namely the type species, P. sprnulosum Thom and a less common species, P. purpurrescens (Sopp) n.comb.