The identification of further new depsidones in the lichen Parmelia notata

Abstract

Two new depsidones, 8-hydroxy-3-methoxy-1,6-dimethyl-11-oxo-11 H-dibenzo[b,e][1,4]dioxepin-7- carboxylic acid (subnotatic acid) (5) and 8-hydroxy-3-methoxy-1,6,9-trimethyl-11-oxo-11 H- dibenzo[b,e][1,4]dioxepin-7-carboxylic acid (isonotatic acid) (7), have been detected in strains of the lichen Parmelia notata Kurok. and isolated and characterized as the corresponding methyl esters. The structures of the latter compounds have been confirmed by synthesis.