InChI=1S/C18H21NO3/c20-18(19-11-5-6-12-19)8-4-2-1-3-7-15-9-10-16-17(13-15)22-14-21-16/h3-4,7-10,13H,1-2,5-6,11-12,14H2/b7-3-,8-4+