InChI=1S/C19H20O7S/c1-12(2)3-10-16-17(20)11-14(18(21)19(16)22)7-4-13-5-8-15(9-6-13)26-27(23,24)25/h3-12,20-22H,1-2H3,(H,23,24,25)/b7-4+,10-3+