NSC266493 Picras-3-ene-2,16-dione, 15-(2-(acetyloxy)-2-methyl-1-oxobutoxy)-13,20-epoxy-1,11,12-trihydroxy-, (1.beta.,11.beta.,12.alpha.,15.beta.)- Picras-3-ene-2,16-dione, 15-[(2-acetyloxy)-2-methyl-1-oxobutoxy]-13,20-epoxy-1,11,12-trihydroxy-, (1.beta.,11.beta.,12.alpha.,15.beta.)- QUASSIMARIN