InChI=1S/C18H14N4O7S.Na/c23-21(24)14-7-9-15(17(11-14)22(25)26)20-13-6-8-16(18(10-13)30(27,28)29)19-12-4-2-1-3-5-12;/h1-11,19-20H,(H,27,28,29);/q;+1/p-1