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