InChI=1S/C20H16O8S/c1-20(11-26-29(23,24)25)8-7-13-16(28-20)10-15(21)18-14(9-17(22)27-19(13)18)12-5-3-2-4-6-12/h2-10,21H,11H2,1H3,(H,23,24,25)