InChI=1S/C17H17NO7S/c19-14-6-4-13(5-7-14)16(20)11-18-17(21)10-3-12-1-8-15(9-2-12)25-26(22,23)24/h1-10,16,19-20H,11H2,(H,18,21)(H,22,23,24)/b10-3+