Chemistry of Two Leprarioid Lichens from Sri Lanka

Abstract

We reported the two species of lichens 𝘓𝘦𝘱𝘳𝘰𝘭𝘰𝘮𝘢 𝘴𝘪𝘱𝘮𝘢𝘯𝘪𝘢𝘯𝘶𝘮 and 𝘓𝘦𝘱𝘳𝘢𝘳𝘪𝘢 𝘢𝘵𝘳𝘰𝘵𝘰𝘮𝘦𝘯𝘵𝘰𝘴𝘢 from Sri Lanka in 2000. The former which was collected from Beragala, was previously reported from South Africa, Colombia and Brazil while the latter, collected from Ramboda, is a new species.

The compounds, atranorin 1, β-sitosterol 2, (+)-usnic acid 3, zeorin 4 and a C₋₄₃ fatty acid ester 5 have been isolated previously from the hexane and dichloromethane extracts of 𝘓 𝘴𝘪𝘱𝘮𝘢𝘯𝘪𝘢𝘯𝘶𝘮. In the present study the methanol extract and the lichen powder of this lichen yielded compounds 1-5 in addition to glyceryl trilinolate 6, 3, 6-dimethyl-2-hydroxy-4- methoxybenzoic acid 7 and a triterpenoid 3β-acetoxyfem-9(11)-ene 8. Chromatography of the lichen powder of 𝘓 𝘢𝘵𝘳𝘰𝘵𝘰𝘮𝘦𝘯𝘵𝘰𝘴𝘢 led to the isolation of five compounds, including compounds 1-4 along with methyl-β-orcinolcarboxylate 9. All compounds were characterized by the physical data (mp, TLC and co-TLC) and spectroscopic methods (UV, ¹H NMR, ¹³C NMR, ²D NMR and MS) [The abstract also includes scientific formulas and symbols to represent key concepts and findings].