Abstract

The aim of this study was to investigate metabolites of the lichen Thamnolia vermicularis (Sw.) Schaer var. subuliformis (Ehrh.). Chloroform, ethyl acetate and methanol extracts of the lichen Thamnolia vermicularis var. subuliformiswere prepared and a high performance liquid chromatographic (HPLC) method was developed for the characterization of depsides in these extracts. All the tested extracts of T. vermicularis var. subuliformis contain depsides baeomycesic, lecanoric acid, barbatic acid and squamatic acid, but in different amounts and relations. Components of this lichen were identified by relative retention time and spectral data. Some preliminary results concerning the evaluation of cytotoxic activity on HeLa cell of the chloroform, ethyl acetate and methanol extracts of the lichen T. vermicularis var. subuliformis are reported in the present study. In vitro cytotoxicity of the extracts on human cancer cell lines Hela was examined. Viability HeLa cells treated with the ethyl acetate and chloroform extracts of T. vermicularis var. subuliformis decreased with increasing concentrations of these extracts. IC₅₀ value after 24 h for the ethyl acetate extract was 162.50 ± 5.80 µg/ml, while for the chloroform extract this value was 159.32 ± 5.16 µg/ml. All the tested concentrations of the ethyl acetate and chloroform lichens extract after 72 h of treatment of HeLa cells showed a cytotoxic effect. The methanolic extract containing the lowest content of baeomycesic and squamatic acid showed the lowest activity.

Key words: Thamnolia vermicularis var. subuliformis, cytotoxic activity, high performance liquid chromatographic (HPLC), depsides.