InChI=1S/C19H18O7S/c1-19(12-25-19)7-6-15-8-13(4-5-18(15)26-27(22,23)24)2-3-14-9-16(20)11-17(21)10-14/h2-11,20-21H,12H2,1H3,(H,22,23,24)/b3-2+,7-6?