4-O-Methylconhypoprotocetraric Acid, a New β-Orcinol Depsidone from the Lichen Xanthoparmelia competita

Abstract

The depsidone 4-O-methylconhypoprotocetraric acid (8-hydroxy-3-methoxy-1,4,6,9-tetramethyl-11-oxo-11H-dibenzo[b,e][1,4]-dioxepin-7-carboxylic acid) (4) has been isolated from the lichen Xanthoparmelia competita together with usnic acid and 4-O-methylhypoprotocetraric acid (3). The structure of compound (4) followed from a combination of spectroscopic data.