InChI=1S/C20H18O10S/c1-20(2)16(30-31(25,26)27)5-10-3-9(4-14(23)19(10)29-20)12-8-28-15-7-11(21)6-13(22)17(15)18(12)24/h3-4,6-8,16,21-23H,5H2,1-2H3,(H,25,26,27)