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