Synthesis and Anti-bacterial Application of Copper(II) Salicyldehyde Schiff Base Complex

Research Article

Austin J Anal Pharm Chem. 2016; 3(4): 1077.

Synthesis and Anti-bacterial Application of Copper(II) Salicyldehyde Schiff Base Complex

Shraddha Shukla*

Department of Chemistry, Guru Ghasidas University, Bilaspur, India

*Corresponding author: Shraddha Shukla, Department of Chemistry, Guru Ghasidas University, Bilaspur, India

Received: November 24, 2016; Accepted: December 13, 2016; Published: December 15, 2016

Abstract

The coordination complex of Cu(II) with the Schiff base derived from salicyldehyde with 5-chloro aniline have been synthesized and characterized by micro analytical data; FT-IR, UV-vis, FAB-mass and X-ray diffraction. Furthermore, in an attempt to improve the antibacterial activity, synthetic analogues i.e. Copper complex has been designed based on the structural properties. Well diffusion method using Nutrient Agar as the medium, we determined the anti-bacterial activity and mechanism of action of these complexes. For antibacterial screening Gram-positive bacteria; Bacillus subtilis, Staphylococcus aureus and Gram-negative bacteria; Escherichia coli, Pseudomonas aeruginosa have been used. The synthesized Cu(II) Schiff base ligands show good or moderates antibacterial activity.

Keywords: Salicyldehyde; Bacillus subtilis; Staphylococcus aureus; Escherichia coli; Pseudomonas aeruginosa; Cu(II) complex

Introduction

Organo-metallic compounds have been used in medicine for centuries. Metal complexes play essential role in pharmaceuticals industry and in agriculture. The metallo elements present in trace quantities play vital roles at the molecular level in living system. The transition metal ions are responsible for proper functioning of different enzymes. The activity of biometals is attained through the formation of complexes with different bioligands and the mode of biological action for complexes depends upon the thermodynamic and kinetic properties. The lipophilicity of the drug is increased through the formation of chelates and drug action is significantly increased due to effective permeability of the drug into the site of action. Interaction of various metal ions with antibiotics may enhance their antimicrobial activity as compared to that of free ligands.

Reproducing complex biological reactivity within a simple synthetic molecule is a challenging endeavor with both intellectual and aesthetic goals. The sequence of examining biological reactivity, creating similar chemical architectures, and determining functional reaction conditions for model systems is a process that allows the biological code of reactivity to be deciphered. The coordination chemistry of Copper(II) attracts much attention because of its biological relevance and its own interesting coordination chemistry such as geometry, flexible redox property, and oxidation state [1- 3]. Nowadays, coordination compounds have been known to be useful in constructing molecular information processing systems, particularly by biological self-organizing processes [4,5]. Especially for this purpose, synthesis, structural and anti-bacterial of Copper(II) complex has been attempted to mimic metalloenzyme [6-9]. Recently, we tried to prepared new anti-bacterial agents against to Gram-positive bacteria; Bacillus subtilis, Staphylococcus aureus and Gram-negative bacteria; Escherichia coli, Pseudomonas aeruginosa.

Experimental

Apparatus and reagent

All the used chemicals and solvents were of A.R. grade. Copper (II) chloride was obtained from Aldrich, Fluca, Loba and Merck chemie. Elemental analysis of the ligand and complexes were performed micro analytically on Elementar Vario EL III Carbo Erba 1108 model, microanalyzer. I.R. spectra of ligand and complex was recorded on Perkin Elmer RX-I spectrophotometer as KBr pellets and FAB-mass were recorded on JEOL SX102/DA-6000 mass spectrometer/ data system using argon/xenon (accelerating voltage 10 KV) SAIF-CDRI, Lucknow. UV-vis. spectra were obtained in methanol by specord-200 spectrometer and Acuta 710 softwere.

Synthesis of schiff base

Schiff base has been synthesized by adding the methanolic solution of salicyldehyde (0.06/0.07mol) with methanolic solution of 5-chloro aniline (0.06/0.07mol) in 1:1 equimolar ratio. The reaction mixture was then refluxed on 5-8 hours. The volume of solvent was reduced until precipitation began, and the mixture was allowed to stand overnight, after which the colored solid was obtained. It was filtered off, recrystallized thrice with ethanol, finally washed with ether, and dried under reduced pressure over anhydrous CaCl2 in desiccators. The purity of the synthesized compounds was monitored by TLC using silica gel-G. Schiff base CAS(R) in 90% yield as yellow crystalline solid and melting point is 110°c. IR (cm-1): 3421(Ph-OH), 1630(CH=N), 1310(S, CH); UV-vis. (λmax): 220, 252, and 326 nm.

Synthesis of complex

The Cu(II) metal complex has been prepared by mixing the methanolic solution of MCl2.nH2O (0.005/0.003mol) with the methanolic solution of Schiff base CAS-(R) (.005/.007mole) in 1:2 molar ratio. The resulting mixture was refluxed on water bath for 8-9 hours. The volume of solvent was reduced until precipitation began, and the mixture was allowed to stand overnight, after which the colored solid was obtained. It was filtered off, recrystallized thrice with ethanol, finally washed with ether, and dried under reduced pressure over anhydrous CaCl2 in desiccators. The purity of the synthesized compounds was monitored by TLC using silica gel-G. Metal complex in 95% yield as dusty yellow crystalline solid and decomposition temp. 148°c. IR (cm-1): 1380(M-O), 1620(CH=N), 550(M-N), 570(MO); UV-vis. (λmax): 208, 311, and 388 nm.

Evaluation of antibacterial screening

All the synthesized compounds were tested for their antibacterial activity against; Gram-positive bacteria; Bacillus subtilis, Staphylococcus aureus and Gram-negative bacteria; Escherichia coli, Pseudomonas aeruginosa. Antibacterial screening was performed by the Well diffusion method using Nutrient Agar as the medium. Twoeight hours old bacterial inoculums containing approximately 104- 106 colony forming units (CFU)/mL were used in these screening. Streptomycin has been used as a standard drug. Recommended concentration (100µl) of the test sample (1mg/mL in DMSO) was introduced in the respective wells.

Results and Discussion

The complexes are stable in atmospheric conditions and soluble in ethanol, methanol, DMF and DMSO. Both the complexes were analyzed for elemental analysis. The colour change of the complex along with decomposition > 148°C shoes characteristic differences between the Schiff base and metal complex. Analytical data of Schiff base and Cu(II) complex are complies in Table 1.