InChI=1S/C19H19NO3/c21-18(7-4-8-19(22)23)20-17-13-11-16(12-14-17)10-9-15-5-2-1-3-6-15/h1-3,5-6,9-14H,4,7-8H2,(H,20,21)(H,22,23)/b10-9+