InChI=1S/C20H23NO4/c1-21(2)8-7-12-10-15(25-4)20(23)18-16(12)13(21)9-11-5-6-14(24-3)19(22)17(11)18/h5-6,10,13H,7-9H2,1-4H3,(H-,22,23)/p+1