Chemistry of Australian Lichens. I. Some Constituents of Parmelia conspersa (Ehrh.) Ach., Ramalina fraxinea (L.) Ach., Usnea barbata (L.) Wigg., and U. ceratina Ach., from the New England Region

Abstract

Each of the species named in the title has yielded (+)-usnic acid, as found in previous investigations in other parts of the world. Other aromatic constituents isolated, except salazinic acid from Parmelia conspersa differ from those previously reported and include a new compound from P. conspersa. It is suggested that usnaric acid, previously obtained from Usnea spp. but unidentified, was a mixture of salazinic and norstictic acids. D-Mannitol or D-arabitol has been isolated from the water-soluble fractions.