InChI=1S/C19H16O8/c1-27-15-9-11(3-5-17(23)24)7-13(19(15)26)12-6-10(2-4-16(21)22)8-14(20)18(12)25/h2-9,20,25-26H,1H3,(H,21,22)(H,23,24)/b4-2+,5-3+