InChI=1S/C22H24N2O7/c25-16(13-24-22(31)8-4-15-2-6-18(27)20(29)12-15)9-10-23-21(30)7-3-14-1-5-17(26)19(28)11-14/h1-8,11-12,16,25-29H,9-10,13H2,(H,23,30)(H,24,31)/b7-3?,8-4+