Showing structure for 10a,10'a-dimethyl (6r,6's)-1,1',5,5',9,9'-hexahydroxy-6,6'-dimethyl-8,8'-dioxo-5h,5'h,6h,6'h,7h,7'h-[2,2'-bixanthene]-10a,10'a-dicarboxylate