New Fusarochromanone Derivatives from the Marine Fungus Fusarium equiseti UBOCC-A-117302

Two new fusarochromanone derivatives, deacetylfusarochromene (1) and deacetamidofusarochrom-2',3-diene (2), along with the previously reported metabolites fusarochromanone TDP-2 (3), fusarochromene (4), 2,2-dimethyl-5-amino-6-(2'E-ene-4'-hydroxylbutyryl)-4-chromone (5), fusarochromanone (6), (-)-chrysogine (7), and equisetin (8), were isolated from the marine fungus Fusarium equiseti UBOCC-A-117302. The structures of the compounds were determined by extensive spectrometric (HRMS) and spectroscopic (1D and 2D NMR) analyses, as well as specific rotation. Among them, 2 and 5 showed inhibition of three protein kinases with IC₅₀ values ranging from 1.42 to 25.48 μM. Cytotoxicity and antimicrobial activity of all isolated compounds were also evaluated. Six fusarochromanone derivatives (1-6) exhibited diverse activities against three cell lines, RPE-1, HCT-116, and U2OS (IC₅₀ values ranging from 0.058 to 84.380 μM). Equisetin (8) showed bactericidal activities against Bacillus cereus and Listeria monocytogenes (MBC values of 7.8 and 31.25 µM, respectively), and bacteriostatic activity against Enterococcus faecalis (MIC value of 31.25 µM). Compounds 2 and 4 showed bacteriostatic activities against Listeria monocytogenes (MIC of 125 µM).