InChI=1S/C16H16O8S/c1-22-14-9-10(4-8-13(14)24-25(19,20)21)3-5-11-6-7-12(17)16(23-2)15(11)18/h3-9,17-18H,1-2H3,(H,19,20,21)/b5-3+