New antiglycation and enzyme inhibitors from Parmotrema cooperi

Lichens are unique individuals which have been widely used in traditional medicines. This study was focused on the bioassay-guided phytochemical investigation, and bioactivity evaluation on a lichens species, Parmotrema cooperi. This first bioassay-directed chemical study on P. cooperi has led to the isolation of ethyl heamatomate (1), atraric acid (2), ethyl orsellinate (3), orsellinic acid (4), lecanoric acid (5), gyrophoric acid (6), and licanorin (7). The structures of 1–7 were mainly elucidated from spectroscopic methods including 1D, and 2D NMR spectroscopy, and mass spectrometry. These compounds were evaluated for their antiglycation, urease, α-chymotrypsin, and β-glucoronidase inhibitory activities. Few of the phenolic compounds showed significant, while most of them showed good inhibition of protein glycation, and urease activities.