Synthesis, Characterization and Biological Potentials of 1-phenylacetyl-pyrrolidine-2-Carboxyaldehyde and its Lanthanoid Complexes

Lanthanoid complexes have found potential application in diverse fields including biology and medicine. The present study aim to synthesize a new dione derivative of 1-phenylacetyl-pyrrolidine-2-carboxyaldehyde and its Lanthanoid complexes and investigate their antimicrobial and antimalarial activities. The ligand 1-phenylacetyl-pyrrolidine-2-carboxyaldehyde (L) and its Lanthanoid complexes; Ce(L)3](NO3)3.2H2O,Pr(L)3(NO3)3.2H2O, and Nd(L)3(NO3)3.2H2Owere synthesized and their structures elucidated by spectroscopic techniques, including ultraviolet-visible (UV-Vis), Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR) spectroscopy, magnetic susceptibility and elemental analysis.The antimicrobial activity of the ligand and its complexes was evaluated by the agar-well diffusion method. The antimalarial activity of Nd(III) complex was assessed using the Peter's 4-day suppressive test in mice. Acute toxicity of Nd(III) complex was evaluated using the Lorke method. The synthesized compounds exhibited UV absorption between 282-380 nm. The FTIR spectra of the compounds showed absorption peaks for carbonyl (C=O) stretch at 1691-1703 cm-1. The 1H-NMR for the ligand and its complexes appeared as multiplets between 7.29-7.50 ppm and their 13C-NMR spectra displayed signals between 127.07-135.40 ppm, and at 173 ppm attributed to the phenyl ring and the carbonyl carbons, respectively.The magnetic susceptibility results revealed the complexes were paramagnetic. Neodymium (III) complex (Nd(L)3(NO3)3.2H2O) exhibited the most potent antimicrobial activity inhibiting more of the test organisms than its congeners.Nd(L)3(NO3)3.2H2Oexhibited a dose-dependent antimalarial activity with a mild to moderate reduction in percentage parasitaemia. Acute toxicity test showed an LD50value of 2,154.07 mg/kg for Nd(L)3(NO3)3.2H2O. The complex is relatively safe and has potential for use as antimicrobial and antimalarial agent