NMR Assignments of Depsides and Tridepsides of the Lichen Family Umbilicariaceae

Article abstract of DOI:10.1016/S0031-9422(97)00958-8

NMR spectral analysis provides important information for the identification of secondary products of chemotaxonomic significance in the lichen genera Umbilicaria and Lasallia (Umbilicariaceae). Two depsides (evernic and lecanoric acids) and eight tridepsides (crustinic, gyrophoric, hiascic, lasallic, 4-O-methylgyrophoric, ovoic and umbilicaric acids and tenuiorin) were isolated from various unrelated lichens. Seven of the ten compounds are important taxonomic characters in the family Umbilicariaceae. 1H and 13C NMR spectral signals were assigned for the compounds and for methyl esters of lecanoric, evernic and gyrophoric acids. Using these NMR data and mass spectrometry, chemical structures were elucidated for two new compounds, papulosic acid (2,6-dihydroxy-3-carboxy-4-methylphenyl orsellinate) from the umbilicariaceous Lasallia papulosa and deliseic acid (lecanoryl 3-acetoxy-4,6-dihydroxy-2-methylbenzoate) from the parmeliaceous Cetrariella delisei.