InChI=1S/C20H20N2O8/c1-28-11-5-3-4-10(6-11)17-18(30-17)20(27)22-13-8-15(29-2)14(23)7-12(13)19(26)21-9-16(24)25/h3-8,17-18,23H,9H2,1-2H3,(H,21,26)(H,22,27)(H,24,25)