Structures of a new type of yellow pigments, falconensones A and B, from Emericella falconensis

Abstract

Two new yellow pigments designated falconensones A 1 and B 2 have been isolated from the mycelium of Emericella falconensis and/or E. fruticulosa along with new azaphilone derivatives, falconensins A–H, and hopane-type triterpenes, zeorin, hopane-7β,22-diol, and hopane-6α,7β,22-triol. The structures of 1 and 2 have been determined by spectroscopic investigations and an X-ray analysis of the p-bromophenylhydrazone of 1 acetone solvate. Compounds 1 and 2 have a novel carbon skeleton: namely, they are cyclopent-2-enone derivatives connected to an extensively conjugated methyl ketone at C-3.