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