beta-D-glucopyranose, cyclic 3,6-(4,4',5,5',6,6'-hexahydroxy(1,1'-biphenyl)-2,2'-dicarboxylate) 1-(3,4,5-trihydroxybenzoate), cyclic 2-2:4-1-ester with 2-(2-carboxy-4,5,6-trioxo-2-cyclohexen-1-yl)-3,4,5-trihydroxybenzoic acid