InChI=1S/C17H18N2O4/c18-13(17(22)23)8-12-9-14(16(21)10-15(12)20)19-7-6-11-4-2-1-3-5-11/h1-5,7,9-10,13,20-21H,6,8,18H2,(H,22,23)/b19-7+/t13-/m0/s1