InChI=1S/C20H16O8S/c1-20(2)8-7-13-16(27-20)10-15(21)18-14(9-17(22)26-19(13)18)11-3-5-12(6-4-11)28-29(23,24)25/h3-10,21H,1-2H3,(H,23,24,25)