Acrostalagmus luteoalbus TK-43 was isolated from the fresh tissue of the marine green alga Codium fragile collected in Sinop, Turkey, in May 2015. For chemical investigation, the fresh mycelia of A. luteoalbus TK-43 were initially grown on PDA medium at 28 ℃ for 4 days and then were used as seed culture to be inoculated for 40 days at room temperature in 1 L conical flasks with solid rice medium (each flask contained 70 g rice, 0.2 g corn flour, 0.3 g peptone, 0.5 g yeast extract, 0.1 g sodium glutamate, 0.1 g methionine, 70 mg magnesium sulfate heptahydrate, 2 mg ferrous sulfate heptahydrate, and 100 mL naturally sourced and filtered seawater, which was obtained from the Huiquan Gulf of the Yellow Sea near the campus of IOCAS, pH 6.5-7.0).