InChI=1S/C18H21NO4/c1-23-16-9-5-14(6-10-16)17(21)12-19-18(22)11-4-13-2-7-15(20)8-3-13/h2-3,5-10,17,20-21H,4,11-12H2,1H3,(H,19,22)