Studies in the usnic acid series. VIII. The biodegradation of (+)-usnic acid by Mortierella isabellina

Abstract

A study involving the biodegradation of (+)-usnic acid (1) by the microorganism Mortierella isabellina is described. Three metabolic products, 6-acetyl-8,9bα-dimethyl-1,9b,2,3-tetrahydro-1α,7,9-trihydroxy-3-oxodibenzofuran (2, (+)-1α-hydroxy-2-desacetylusnic acid), (+)-2-desacetylusnic acid (3), and (+)-6-acetyl-8,9b α-dimethyl-1,9b-dihydro-2-acetoxy-3,7,9,trihydroxy-1-oxodibenzofuran (4, (+)-2-acetoxyusnic acid) are isolated and characterized. By means of radioactively labelled precursors, some information about the biodegradation sequence is derived.