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