InChI=1S/C19H20O5S/c20-18(14-13-16-7-2-1-3-8-16)11-5-4-9-17-10-6-12-19(15-17)24-25(21,22)23/h1-4,6-10,12,15H,5,11,13-14H2,(H,21,22,23)/b9-4+