InChI=1S/C21H26N2O4/c1-4-13-11-22(2)17-9-20(18-10-21(13,25)15(17)12-27-18)14-7-5-6-8-16(14)23(26-3)19(20)24/h4-8,15,17-18,25H,9-12H2,1-3H3/b13-4-/t15-,17+,18-,20+,21-/m1/s1