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