InChI=1S/C16H12N4O9S2/c21-15-13(18-17-9-1-5-11(6-2-9)30(24,25)26)14(16(22)23)19-20(15)10-3-7-12(8-4-10)31(27,28)29/h1-8,21H,(H,22,23)(H,24,25,26)(H,27,28,29)/b18-17+