InChI=1S/C19H17NO7S/c1-10-7-12-16(23)17(24)18(11-3-4-14(21)15(22)9-11)27-19(12)13(8-10)20-5-2-6-28(20,25)26/h3-4,7-9,21-22,24H,2,5-6H2,1H3