Lichen Evernia prunastri of the Parmeliaceae family, also known as oakmoss, thrives on trunks of oak trees in mountainous temperate forests of Europe and North America. In the present study the evaluation of different extracts and fractions antioxidant, anti-inflammatory and inhibitory activity of aldose reductase enzyme, showed remarkable results. LOX and ALR2 inhibitory activities of E.prunastri, are presented for the first time in this study. The GC-MS analysis of the pentane extract by the use of two different solvents, pentane and acetone, led to the identification of a plurality of compounds found for the first time in this species. The major constituents found were Diacetone alcohol (1% and 38,27% in pentane and acetone respectively), the crown ether 1,4,7,10,13,16 Hexaoxacyclooctadecane (18.29% and 2.14%), and 3,5-Di-tertbutylphenol (9.12% and 1.51%). Furthermore, three known aromatic compounds and two depsides were isolated from the CH2Cl2 extract.