InChI=1S/C21H30N4O4/c1-16(2)12-19(24-21(27)25-8-10-28-11-9-25)20(26)23-18(13-22)15-29-14-17-6-4-3-5-7-17/h3-7,16,18-19H,8-12,14-15H2,1-2H3,(H,23,26)(H,24,27)/t18-,19+/m1/s1