InChI=1S/C28H32N4O4/c33-32(12-1-2-13-32)14-17-36-27-9-8-25-19-24(27)21-35-16-4-3-15-34-20-22-6-5-7-23(18-22)26-10-11-29-28(30-25)31-26/h3-11,18-19H,1-2,12-17,20-21H2,(H,29,30,31)/b4-3+