InChI=1S/C18H19NO9S/c1-27-17-9-11(2-7-16(17)28-29(24,25)26)8-14(21)18(23)19-10-15(22)12-3-5-13(20)6-4-12/h2-9,15,20-22H,10H2,1H3,(H,19,23)(H,24,25,26)/b14-8-