InChI=1S/C14H14N4O4/c19-13-11(7-21-17-13)15-5-9-1-2-10(4-3-9)6-16-12-8-22-18-14(12)20/h1-6,11-12H,7-8H2,(H,17,19)(H,18,20)/b15-5+,16-6+