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