InChI=1S/C20H19N3O4/c24-11-12(25)9-10-27-23-18-14-6-2-4-8-16(14)21-19(18)17-13-5-1-3-7-15(13)22-20(17)26/h1-8,12,21,24-25H,9-11H2,(H,22,26)/b19-17-,23-18+/t12-/m1/s1