Antimicrobial and Antioxidant Activities of Extracts and Lichen Acids Obtained from SomeUmbilicariaSpecies from Central Anatolia, Turkey

Abstract

In this study, the methanolic extracts and lichens acids obtained from six Umbilicaria species were tested for their antimicrobial activity (against three Gram-positive bacteria, five Gram-negative bacteria and two yeasts species) and their antioxidant activity. Total phenolic content in the extracts was determined by the Folin–Ciocalteu assay. It ranged from 0.91 to 48.25 mg gallic acid/g. The antioxidant ability was measured using a free radical-scavenging activity assay using 2,2-diphenyl-1-picrylhydrazyl (DPPH). The methanolic extracts showed moderate DPPH radical-scavenging activity. Among the lichen acids, umbilicaric acid showed the highest antioxidant activity with 68.14% inhibition. Antimicrobial activity was determined by the agar diffusion method. Extracts were found to possess antimicrobial activity against some of the bacteria and yeasts tested. Gyrophoric acid was effective against six out of eight bacteria tested, but no activity was observed against the yeasts. Practical Applications This article evaluates antimicrobial, antioxidant activities and their active compounds have been shown in some Umbilicaria lichens species. This is the first study reporting in vitro biological activities of U. aprina var. halei, U. cylindrica, U. decussata, U. leiocarpa, U. nylanderiana, U. virginis, gyrophoric acid, leconaric acid and umbilicaric acid isolated from them. Results of this study will contribute significantly to efforts to used antimicrobial and antioxidant agents in the country and elsewhere in Turkey.