63306-30-9 Bruceoside A Picras-1-en-21-oic acid, 11,12-dihydroxy-3,16-dioxo-13,20-epoxy-2-(beta-D-glucopyranosyloxy)-15-((3-methyl-1-oxo-2-butenyl)oxy)-, methyl ester, (11-beta,12-alpha,15-beta)-