InChI=1S/C20H18O12S/c1-28-13-7-9(3-5-11(13)21)16-15-18(22)31-17(20(15,24)19(23)30-16)10-4-6-12(14(8-10)29-2)32-33(25,26)27/h3-8,15-17,21,24H,1-2H3,(H,25,26,27)