InChI=1S/C16H16N2O6/c1-8-12(15(19)20)14(13(9(2)17-8)16(21)24-3)10-5-4-6-11(7-10)18(22)23/h4-7,14,17H,1-3H3,(H,19,20)/t14-/m1/s1