Indole Diterpenoids and Isocoumarin from the Fungus, Aspergillus flavus, Isolated from the Prawn, Penaeus vannamei

Two new indole-diterpenoids (1 and 2) and a new isocoumarin (3), along with the known beta-aflatrem (4), paspalinine (5), leporin B (6), alpha-cyclopiazonic acid (7), iso-alpha-cyclopiazonic acid (8), ditryptophenaline (9), aflatoxin B-1 (10), 7-O-acetylkojic acid (11) and kojic acid (12), were isolated from the fermentation broth of the marine-derived fungus, Aspergillus flavus OUCMDZ-2205. The structures of Compounds 1-12 were elucidated by spectroscopic analyses, quantum ECD calculations and the chemical method. New Compound 1 exhibited antibacterial activity against Staphylococcus aureus with a MIC value of 20.5 mu M. Both new Compounds 1 and 2 could arrest the A549 cell cycle in the S phase at a concentration of 10 mu M. Compound 1 showed PKC-beta inhibition with an IC50 value of 15.6 mu M. In addition, the absolute configurations of the known compounds, 4-6 and leporin A (6a), were also determined for the first time.