Synonyms: ISOBRUCEIN A;NSC-279503;Neuro_000141;AC1L869E;57629-50-2;NSC279503;NCI60_002273;Picras-3-en-21-oic acid,20-epoxy-1,11,12-trihydroxy-15-(3-methyl-1-oxobutoxy)-2,16-dioxo-, methyl ester, (1.beta.,11.beta.,12.alpha.,15.beta.)-;Picras-4-en-21-oic acid,20-epoxy-1,11,12-trihydroxy-15-(3-methyl-1-oxobutoxy)-2,16-dioxo-, methyl ester