Pigments of Fungi. XXXVII. Pisoquinone, a New Naphthalenoid Pulvinic Acid From the Fungus Pisolithus arhizus

Abstract

A new naphthalenoid pulvinic acid, pisoquinone (3), is isolated and characterized from a white skinned variant of the ectomycorrhizal gastromycete Pisolithus arhizus. The structural elucidation is facilitated by analysis of the ¹³C n.m.r. spectrum of norbadione A (2) and that of its naturally occurring potassium salt (1), assignments of which are reported here for the first time.