InChI=1S/C18H15NO7S/c1-18(9-25-27(22,23)24)7-6-11-15-12(8-13(17(20)21)16(11)26-18)10-4-2-3-5-14(10)19-15/h2-8,19H,9H2,1H3,(H,20,21)(H,22,23,24)