InChI=1S/C22H24N2O5/c25-18-7-1-16(2-8-18)5-11-21(28)23-14-13-20(27)15-24-22(29)12-6-17-3-9-19(26)10-4-17/h1-12,20,25-27H,13-15H2,(H,23,28)(H,24,29)/b11-5?,12-6+