InChI=1S/C19H20O8S/c1-10(2)3-5-13-15(21)7-12(8-16(13)22)19-18(26-19)11-4-6-14(20)17(9-11)27-28(23,24)25/h3-10,18-22H,1-2H3,(H,23,24,25)/b5-3+