InChI=1S/C18H19NO7S/c1-25-15-9-7-14(8-10-15)17(26-27(22,23)24)12-19-18(21)16(20)11-13-5-3-2-4-6-13/h2-11,17,20H,12H2,1H3,(H,19,21)(H,22,23,24)/b16-11-