NSC330518 Picrasa-1,4-dien-21-oic acid, 15-[[4-(acetyloxy)-3,4-dimethyl-1-oxo-2-pentenyl]oxy]-13,20-epoxy-/2,11,12-trihydroxy-3,16-dioxo-, methyl ester, [11.beta.,12.alpha.,15.beta.(E)]-