InChI=1S/C20H20N4O3.C4H4O4/c1-25-23-19(21)15-7-3-13(4-8-15)17-11-12-18(27-17)14-5-9-16(10-6-14)20(22)24-26-2;5-3(6)1-2-4(7)8/h3-12H,1-2H3,(H2,21,23)(H2,22,24);1-2H,(H,5,6)(H,7,8)/b;2-1-