InChI=1S/C20H16O10S/c1-20(2)6-5-10-13(29-20)8-12(22)15-16(23)17(24)18(28-19(10)15)9-3-4-11(21)14(7-9)30-31(25,26)27/h3-8,21-22,24H,1-2H3,(H,25,26,27)