n-[3-(3-[2,5-dihydro-4-(1-methyl-1h-indol-3-yl)-2,5-dioxo-1h-pyrrol-3-yl]-1h-indol-1-yl)propyl]-3',6'-dihydroxy-3-oxospiro[isobenzofuran-1[3h],9'-[9h]xanthene]-5-carboxamide