Extracts of five Cladonia lichens as sources of biologically active compounds

Five lichen species of Cladonia genus (C. fimbriata, C. furcata, C. subulata, C. foliacea and C. rangiferina) were examined.
We described the chemical composition of the acetone extracts of the mentioned lichens and the antioxidant, antimicrobial
and antitumor activities of their extracts. The phytochemical analysis was determined by HPLC-UV method. The depside
(atranorin), depsidones (hypoprotocetraric acid and fumarprotocetraric acid) and dibenzofurane (usnic acid) were identified
from these lichens. Antioxidant activity was evaluated by measuring the scavenging capacity of tested samples on 2,2-
diphenyl-1-picrylhydrazyl (DPPH) radicals, reducing power of samples and determination of total phenolic and flavonoid
compounds in extracts. As a result of the antioxidant activity C. furcatа showed the largest effect. The minimum inhibitory
concentration (MIC) against five bacterial and 10 fungi was established. The extract of lichen C. fimbriata showed the
strongest antibacterial activity (MIC values ranging from 0.625 to 20 mg/mL) while, extract of the lichen C. subulata showed
the strongest antifungal activity (MIC values were 0.625 - 20 mg/mL). Cytotoxic activity was tested using 3-(4,5-
dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method and all samples were found to be strong anticancer
activity toward used cell lines with IC50 values ranging from 11.69 to 140.13 μg/mL.