InChI=1S/C19H21NO7S/c1-26-17(21)19(18(22)27-2,12-14-6-4-3-5-7-14)13-15-8-10-16(11-9-15)20-28(23,24)25/h3-11,20H,12-13H2,1-2H3,(H,23,24,25)