A new phenolic metabolite, involutone, isolated from the mushroom Paxillus involutus

Abstract

A new optically active metabolite, involutone, was found in methanol, ethanol, or n-butanol extracts of freshly collected Paxillus involutus. The structure of this compound was proved to be 5-(3,4-dihydroxyphenyl)-2-(4-hydroxyphenyl)-2-hydroxy-4-cyclopenten-1,3-dione on the basis of the spectral and chemical properties of involutone and its tetraacetyl derivative. In addition, a number of compounds of known structures such as linoleic and crotonic acids, mannitol, ergosterol, involutin, as well as methyl, ethyl, or n-butyl-β-D-glucopyranosides, and methyl, ethyl, or n-butyl linoleates, depending in both cases on the alcohol used in the extraction, were also isolated in a pure state from the mushroom.Key words: Paxillus involutus, Brown Roll-rim, metabolite isolation, structure study, quaternary hydroxycyclopentanedione, NMR of mushroom pigments, glucosides and linoleates, enzymic glucosylation and esterification.