InChI=1S/C17H17NO8S/c19-13-5-1-11(2-6-13)9-15(20)17(22)18-10-16(21)12-3-7-14(8-4-12)26-27(23,24)25/h1-9,16,19-21H,10H2,(H,18,22)(H,23,24,25)/b15-9-