InChI=1S/C20H20N2O6/c1-27-14-8-20(26,6-4-12(14)23)18-17(19(24)25)16-13(28-18)3-2-11-15(16)10(5-7-21)9-22-11/h2-4,6,8-9,17-18,22,26H,5,7,21H2,1H3,(H,24,25)