InChI=1S/C19H18O7S/c1-12(2)3-7-15-9-13(6-8-18(15)26-27(23,24)25)4-5-14-10-16(20)19(22)17(21)11-14/h3-11,20-22H,1H2,2H3,(H,23,24,25)/b5-4+,7-3+