InChI=1S/C18H19NO7S/c1-25-16-8-6-14(7-9-16)17(26-27(22,23)24)12-19-18(21)10-5-13-3-2-4-15(20)11-13/h2-11,17,20H,12H2,1H3,(H,19,21)(H,22,23,24)/b10-5+