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