InChI=1S/C13H17NO7S/c1-9-7-10(20-13(9)16)4-5-11(21-22(17,18)19)8-14-6-2-3-12(14)15/h4,7,11H,2-3,5-6,8H2,1H3,(H,17,18,19)/b10-4+