InChI=1S/C18H13N3O4/c22-14(23)9-25-21-16-11-6-2-4-8-13(11)19-17(16)15-10-5-1-3-7-12(10)20-18(15)24/h1-6H,7-9H2,(H,22,23)/b17-15-,21-16+