InChI=1S/C19H21NO7S/c21-19(20-11-5-7-16(13-20)27-28(22,23)24)8-4-2-1-3-6-15-9-10-17-18(12-15)26-14-25-17/h1-4,6,8-10,12,16H,5,7,11,13-14H2,(H,22,23,24)/b2-1+,6-3+,8-4+