InChI=1S/C21H26N2O4/c22-19(26)15-4-3-13-9-16-21(27)6-5-14(24)10-20(21,17(13)18(15)25)7-8-23(16)11-12-1-2-12/h3-4,12,16,25,27H,1-2,5-11H2,(H2,22,26)/t16-,20-,21-/m1/s1