In Vitro Antiproliferative Activity of Echinulin Derivatives from Endolichenic Fungus Aspergillus sp. against Colorectal Cancer

The endolichenic fungus <i>Aspergillus</i> sp. was isolated from the lichen <i>Xanthoparmelia conspersa</i> harvested in France. <i>Aspergillus</i> sp. was grown on a solid culture medium to ensure the large-scale production of the fungus with a sufficient mass of secondary metabolites. The molecular network analysis of extracts and subfractions enabled the annotation of 22 molecules, guiding the purification process. The EtOAc extract displayed an antiproliferative activity of 3.2 ± 0.4 µg/mL at 48 h against human colorectal cancer cells (HT-29) and no toxicity at 30 µg/mL against human triple-negative breast cancer (TNBC) cells (MDA-MB-231) and human embryonic kidney (HEK293) non-cancerous cells. Among the five prenylated compounds isolated, of which four are echinulin derivatives, compounds <b>1</b> and <b>2</b> showed the most important activity, with IC₅₀ values of 1.73 µM and 8.8 µM, respectively, against HT-29 cells.