InChI=1S/C19H20O6S/c20-17(6-2-1-4-15-8-11-18(21)12-9-15)13-10-16-5-3-7-19(14-16)25-26(22,23)24/h2-3,5-9,11-12,14,21H,1,4,10,13H2,(H,22,23,24)/b6-2+