InChI=1S/C20H20O10S/c1-10(9-29-31(26,27)28)2-4-14-19(25)18-16(24)7-12(22)8-17(18)30-20(14)13-5-3-11(21)6-15(13)23/h2-3,5-8,14,20-24H,4,9H2,1H3,(H,26,27,28)/b10-2+