Studies in the usnic acid series. VII. The biodegradation of (+)-usnic acid by a <i>Pseudomonas</i> species. Isolation, structure determination, and synthesis of (+)-6-desacetylusnic acid

Abstract

Studies on the biodegradation of (+ )-usnic acid (1) by a Pseudomonas species have revealed a novel aromatic deacylation process. The isolated metabolite, (+)-6-desacetylusnic acid (2) is crystalline and its structure is established by means of spectroscopic and chemical methods. The synthesis of 2 from usnic acid (1) is also reported and provides conclusive evidence for the structure of this metabolite.