Synthesis, Spectral Characterization and In Vitro Antihelmintic Evaluations of Cu(II) and Co(II) Complexes with A Novel Schiff Base Ligand

Abstract

The novel Schiff base ligand (Z)-2-(benzalideneamino)-3-(1H-indol-3-yl)propanoic acid was synthesized 
by condensation reaction of benzaldehyde and tryptophan. The complexes of this ligand of Cu (II) and Co 
(II) were successfully synthesized and characterized physiochemically and spectroscopically. The ligand and the complexes showed a good yield ranging from 95 % - 98 %. The FTIR spectroscopic data showed 
appearance of the azomethine (C=N), carbonyl group (C=O) and -OH group with peak at 1692 cm^-1, 1580 cm ^-1and 3399 cm^-1 respectively in the spectrum of Schiff base. The molar conductivity data of the Schiff 
base was found to be 3.5 Ω^-1cm²mol^-1 indicating non-electrolytic nature whereas that of Cu and Co 
complexes range between 103 -160 Ω^-1 cm² mol^-1  indicated that the complexes were weak electrolyte in 
water. On the basis of magnetic and electronic spectral data, octahedral geometry was proposed for all the 
complexes. The UV-Vis spectra showed metal-ligand bond formation. The complexes demonstrated 
various significant antihelmintic activities against Taenia spp compared to the ligand. The Co complex 
showed similar biological activity compared to the ligand while Cu  complex showed biological activity 
higher than the ligand. Both the Co complex and the ligand showed a lower activity compared to the 
standard drug except for Cu complex that showed the same activity as the standard drug hence, the Cu 
complex synthesized is a good replacement for the existing drug