InChI=1S/C17H17NO8S/c19-13-5-1-11(15(20)9-13)4-8-17(22)18-10-16(21)12-2-6-14(7-3-12)26-27(23,24)25/h1-9,16,19-21H,10H2,(H,18,22)(H,23,24,25)/b8-4+