InChI=1S/C20H21N3O5/c1-3-22(4-2)14-6-5-13-11-15(20(27)28-16(13)12-14)19(26)21-9-10-23-17(24)7-8-18(23)25/h5-6,9-12H,3-4,7-8H2,1-2H3,(H,21,26)/b10-9-