InChI=1S/C18H18N2O6/c21-16(22)13(8-11-4-2-1-3-5-11)19-7-6-12-9-14(17(23)24)20-15(10-12)18(25)26/h1-7,9,13,15,20H,8,10H2,(H,21,22)(H,23,24)(H,25,26)/b12-6-,19-7-/t13-,15-/m0/s1