Ethyl orsellinate is a lichen metabolite and a derivative of lecanoric acid with antiproliferative and antitumour activities^[1]. Ethyl Orsellinate is against A. salina for the cytotoxic activity with an LC₅₀ of 495 μM^[2]. In Vitro: Ethyl Orsellinate (0-50 μg/ml; 48 hours) inhibits Hep-2 cells, MCF-7 breast cancer cells, and 786-0 kidney carcinoma cells, as well as B16-F10 murine melanoma and non-cancerous Vero cells (IC₅₀s=31.2, 70.3, 47.5, 64.8, and 28.1 µg/ml, respectively)^[2].