InChI=1S/C19H20O6S/c20-17(4-2-1-3-15-5-11-18(21)12-6-15)10-7-16-8-13-19(14-9-16)25-26(22,23)24/h2,4-6,8-9,11-14,21H,1,3,7,10H2,(H,22,23,24)/b4-2+