InChI=1S/C19H20O5S/c20-18(9-5-4-8-16-6-2-1-3-7-16)13-10-17-11-14-19(15-12-17)24-25(21,22)23/h1-4,6-8,11-12,14-15H,5,9-10,13H2,(H,21,22,23)/b8-4+