InChI=1S/C19H16O8/c1-26-19(25)17(10-12-2-5-13(20)14(21)9-12)27-16-6-3-11(8-15(16)22)4-7-18(23)24/h2-10,20-22H,1H3,(H,23,24)/b7-4+,17-10-