InChI=1S/C21H16N2O8/c24-15-11-7-9(30-21-18(27)16(25)17(26)19(31-21)20(28)29)1-2-10(11)13-12-8(3-5-22-13)4-6-23-14(12)15/h1-7,16-19,21,25-27H,(H,28,29)