InChI=1S/C20H18N4O4/c1-10-4-7-16(11(2)8-10)21-20(28)17(12(3)25)24-23-13-5-6-14-15(9-13)19(27)22-18(14)26/h4-9,17H,1-3H3,(H,21,28)(H,22,26,27)