InChI=1S/C14H10N2O6.2Na/c17-11-3-1-7(5-9(11)13(19)20)15-16-8-2-4-12(18)10(6-8)14(21)22;;/h1-6,15,17H,(H,19,20)(H,21,22);;/q;2*+1/p-2/b16-8-;;