InChI=1S/C18H19NO6S/c1-24-16-10-8-15(9-11-16)17(25-26(21,22)23)13-19-18(20)12-7-14-5-3-2-4-6-14/h2-12,17H,13H2,1H3,(H,19,20)(H,21,22,23)/b12-7+