InChI=1S/C20H18N2O4/c23-16-17(24)22-13-9-15-14(25-10-26-15)8-11(13)12-2-7-21-6-1-3-19(16)4-5-20(12,22)18(19)21/h1-3,8-9,16,18,23H,4-7,10H2/t16-,18-,19-,20+/m0/s1