InChI=1S/C20H16O9S/c1-20(2)8-7-12-14(28-20)9-13(21)15-16(22)17(23)18(27-19(12)15)10-3-5-11(6-4-10)29-30(24,25)26/h3-9,21,23H,1-2H3,(H,24,25,26)