InChI=1/C12H14N2O6/c1-6(10(15)16)13-3-2-7-4-8(11(17)18)14-9(5-7)12(19)20/h2-4,6,9,14H,5H2,1H3,(H,15,16)(H,17,18)(H,19,20)/b7-2-,13-3-/t6?,9-/s2