NSC341651 Picras-3-ene-2,16-dione, 11,20-epoxy-1,11,12-trihydroxy-6-[(3-methyl-1-oxo-2-butenyl)oxy]-, (6.alpha.,11.beta.,12.alpha.)- SENECIOYLCHAPARRIN, 6-ALPHA- (B815099K220)