InChI=1S/C18H21NO7S/c1-25-15-9-7-13(8-10-15)16(20)12-19-18(21)11-17(26-27(22,23)24)14-5-3-2-4-6-14/h2-10,16-17,20H,11-12H2,1H3,(H,19,21)(H,22,23,24)