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