Awajanomycin, a cytotoxic γ-lactone-δ-lactam metabolite from marine-derived Acremonium sp AWA16-1

The new fungal metabolite awajanomycin ( 1), which has gamma-lactone-delta-lactam rings, was isolated from the marine-derived fungus Acremonium sp. AWA16-1, which had been collected from sea mud off Awajishima Island in Japan. The structure of 1 was elucidated by spectroscopic analysis and chemical methods. Awajanomycin ( 1) and its derivative ( 2) inhibited the growth of A549 cells with IC50 values of 27.5 and 46.4 mu g/mL, respectively.