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