Bolu'dan toplanan bazı likenlerin biyolojik aktivitelerinin (antibakteriyel, antioksidant ve antiproliferatif) belirlenmesi ve bazı liken metabolitlerinin HPLC analizi

Lichens are symbiotic organisms which are composed of fungi and algae. Various species have been used for treatment of stomach diseases, diabetes, bronchitis and skin diseases throughout the ages. The aim of present thesis was to investigate the biological activities (antibacterial, antioxidant and antiproliferation) and chemical contents of thirteen different lichen species (Ramalina fraxinea, Ramalina farinacea, Bryoria capillaris, Evernia prunastri, Ramalina fastigiata, Evernia divaricata, Anapthycia cilliaris, Pseudoevernia furfuracea, Lobaria pulmonaria, Platismatia glauca, Cetraria islandica, Letharia vulpina and Usnea florida). Antibacterial activity of lichens was evaluated by disc diffusion method (Kirby-Bauer). Methanol extract of R. fraxinea was the most active antibacterial agent, inhibiting growth of 8 tested species of bacteria with the diameter of inhibition zone ranging from 9.5 mm to 30.5 mm. Antioxidant activities were determined by free radical scavenging (DPPH), total phenol and total flavonoid assays. P.furfuracea showed the largest DPPH radical scavenging activity (81.1%). Highest total phenol and flavonoid compounds were identified in B. capillaris (respectively 163.3 and 154.5 mg CE/g dried mass). Antiproliferative activities on the human breast cancer (MCF-7) and human hepatocellular carcinoma (HepG2/C3A) cell lines of six lichen species were determined by MTT assay. Only acetone extracts of samples showed antiproliferative activity against human hepatocellular carcinoma (HepG2/C3A) cell line. L. pulmonaria exhibited the best antiproliferative activity with IC50 value of 90.2±1.2 μg/mL. Lastly, Quantification of chosen five standards (usnic acid, atranorin, stictic acid, evernic acid and fumarprotocetraric acid) in thirteen lichen species was performed by HPLC. Fumarprotocetraric acid was only found in C. islandica, while stictic acid was mostly detected in L. pulmonaria. U. florida had the greatest amount of usnic acid. E. prunastri was the main source of evernic acid. Atranorin was mostly detected in P. furfuracea. Fourteen different lichen compounds in the lichen species were also identified qualitatively by comparing of the absorbance spectral data in the literatures.