InChI=1S/C18H12O8/c1-7(19)24-18-17-12(8-4-2-3-5-10(8)26-18)15(22)13-11(25-17)6-9(20)14(21)16(13)23/h2-6,18,20-21,23H,1H3/t18-/m1/s1