InChI=1S/C19H20O5S/c20-18(14-8-7-11-16-9-3-1-4-10-16)15-19(24-25(21,22)23)17-12-5-2-6-13-17/h1-7,9-13,19H,8,14-15H2,(H,21,22,23)/b11-7+