InChI=1S/C20H20N2O9/c1-29-14-5-9(3-4-12(14)23)17-18(31-17)20(28)22-11-7-15(30-2)13(24)6-10(11)19(27)21-8-16(25)26/h3-7,17-18,23-24H,8H2,1-2H3,(H,21,27)(H,22,28)(H,25,26)