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