InChI=1S/C19H22N2O9S2/c1-28-21-11-8(9(16(21)25)7-20-19(31-2)32-3)5-4-6-10(11)29-18-14(24)12(22)13(23)15(30-18)17(26)27/h4-7,12-15,18,22-24H,1-3H3,(H,26,27)/b9-7+