InChI=1S/C20H20N2O3/c1-19(2)11-8-10-6-5-7-12-14(10)16(18(24)22(12)4)15(11)17-20(3,25-17)9-13(23)21-19/h5-8,17H,9H2,1-4H3,(H,21,23)/t17-,20+/m1/s1