InChI=1S/C21H23N3O4/c1-4-20(2,3)17-13(12-7-5-6-8-14(12)22-17)11-15-18(26)24-10-9-16(25)21(24,28)19(27)23-15/h4-8,11,16,22,25,28H,1,9-10H2,2-3H3,(H,23,27)/b15-11-