InChI=1S/C18H20N2O3/c19-15(11-13-7-3-1-4-8-13)17(21)20-16(18(22)23)12-14-9-5-2-6-10-14/h1-10,15-16H,11-12,19H2,(H,20,21)(H,22,23)/t15-,16-/m0/s1