InChI=1S/C16H17NO5S/c1-2-3-5-10-15(22-23(19,20)21)11-6-7-12-16(18)17-13-8-4-9-14-17/h1,6-8,11-13,15H,4,9-10,14H2,(H,19,20,21)/b11-6-,12-7+