InChI=1S/C17H17NO8S/c19-13-4-1-12(2-5-13)3-6-16(21)18-11-15(26-27(23,24)25)17(22)9-7-14(20)8-10-17/h1-10,15,19,22H,11H2,(H,18,21)(H,23,24,25)/b6-3+