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