Speculations of various authors concerning the biosynthesis of sulochrin are discussed. New evidence, derived from studies utilising mutants of Aspergillus terreus and from degradation of [14C]sulochrin prepared from cultures of this organism in media containing either [2-14C]acetic acid or [2-14C]malonic acid, favours a pathway involving combination of two units related in molecular structure to o-orsellinic acid.
