Cytotoxicity of lecanoric acid isolated from the lichen Parmotrema tinctorium

The widespread in Russia lichen Parmotrema tinctorium (Despr. ex Nyl.) Hale accumulates orcinolic depsid – lecanoric acid in the core layer of the thallus, which potentially has biological activity. In the present study, we isolated and characterized lecanoric acid and evaluated its cytotoxic properties. The structure of lecanoric acid was confirmed based on spectral data (NMR, MS, and IR). The cytotoxic activity of the isolated compounds was assessed against cancer (Panc-1, A 549, T98G, HeLa) and normal (HEK293) human cell lines using the MTT assay. It was shown that lecanoric acid exhibited moderate cytotoxicity against the HeLa cervical carcinoma cell line with IC₅₀ values of 121 μmol. The results of the performed docking and molecular modeling indicate the potential binding of lecanoric acid to AKT 1 and PI3Kα proteins. These results highlight the potential of lichen depside as a source of anticancer drugs and require further study of its mechanisms of action.

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