Ambewelamide A Butanoic acid, (1aS,2S,4aR,6aS,6bR,7aS,8S,10aR,12aS,12bR)- 8-(acetyloxy)-1a,2,6a,6b,7a,8,12a,12b-octahydro- 5,11-dioxo-5H,11H-4a,10a-epidithio-4H,10H-bisoxireno[g,g'] pyrazino[1,2-a:4,5-a']diindol-2-yl ester NSC712399