InChI=1S/C17H17NO6S/c19-16(14-7-9-15(10-8-14)24-25(21,22)23)12-18-17(20)11-6-13-4-2-1-3-5-13/h1-11,16,19H,12H2,(H,18,20)(H,21,22,23)/b11-6+