Prenylated indole alkaloids from co-culture of marine-derived fungi Aspergillus sulphureus and Isaria felina

Five new prenylated indole alkaloids, 17-hydroxynotoamide D ( 1 ), 17- O -ethylnotoamide M ( 2 ), 10- O -acetylsclerotiamide ( 3 ), 10- O -ethylsclerotiamide ( 4 ), and 10- O -ethylnotoamide R ( 5 ) were isolated from a co-culture of marine-derived fungi Aspergillus sulphureus KMM 4640 and Isaria felina KMM 4639. The structures of 1 − 5 were determined by detailed analysis of spectroscopic data and by comparison with related known compounds. The absolute configurations of 1 − 5 were determined by time-dependent density functional theory (TD-DFT) calculations of ECD spectra. Compound 2 is able to inhibit the colony formation of human prostate cancer cells 22Rv1 at non-cytotoxic concentration of 10 μM.