A new Schiff base of o-phenylenediamine and m-hydroxybenzaldehyde was synthesized by condensation reaction. The Schiff base and its metal complexes of Co(II) and Ni(II) were then characterized spectroscopically. The complexes were tested for their antimicrobial properties using six selected micro-organisms, viz: (1) Staphylococcus aereus, (2) Pseudomonas aeruginosa (3) Escherichia coli (4) Enterococcus faecalis (5) Klebsiella Pneumonia and (6) Candida albicans. Results showed important antimicrobial activities which are believed to be beneficial and could be applied safely in the treatment of infections caused by any of these bacteria.
Table of Contents
1. INTRODUCTION
2. EXPERIMENTAL METHODS
2.1 Synthesis of Schiff Base Ligand and Metal Complexes
2.2 Fourier Transform Infrared (FTIR) and UV/VIS Spectroscopy
2.3 Antimicrobial Assay
3. RESULTS AND DISCUSSION
3.1 Infrared and UV/VIS Spectroscopy
3.2 Zones of Inhibition and Minimum Inhibitory Concentration (MIC)
4. CONCLUSION
Research Objectives and Key Themes
This study aims to synthesize a novel Schiff base ligand derived from o-phenylenediamine and m-hydroxybenzaldehyde, along with its corresponding Co(II) and Ni(II) metal complexes. The research investigates the structural characteristics of these compounds using spectroscopic techniques and evaluates their potential efficacy as antimicrobial agents against various bacterial and fungal strains to address the challenge of antibiotic resistance.
- Synthesis of Schiff base ligands and metal coordination complexes
- Spectroscopic characterization using FTIR and UV/VIS analysis
- Evaluation of antimicrobial activity via the zone of inhibition (Kirby-Bauer) test
- Determination of Minimum Inhibitory Concentration (MIC) values
- Comparative analysis of metal complexes versus uncomplexed Schiff base
Excerpt from the Book
INTRODUCTION
Coordination compounds also known as complexes are molecules that possess a metal centre that is bound to ligands (ions, or molecules that donate electrons to the metal)1-3. These complexes can be neutral or charged. When the complex is charged, it is stabilized by neighbouring counter-ions4-6. A coordination complex is a product of a Lewis acid-base reaction in which neutral molecules or anions (ligands) bond to a central metal atom (or ion) by coordinate covalent bonds. Coordination compounds are very useful in biological systems as they play vital role in disease treatment and control8-12.
A Schiff base complex is a coordination compound formed by a Schiff base ligand and a metal. The development in the field of bio-inorganic chemistry has increased the interest in Schiff base complexes, since it has been recognized that many of these complexes may serve as models for biologically important species13. Owing to the antimicrobial efficacy of Schiff base, it has been used over the years in the manufacture of antibiotics; however due to constant abuse of antibiotics, many strains of bacteria have grown resistance to most available brands of the complex13-16. Therefore, researches on potential metallated Schiff bases as antimicrobial agents are necessary in manufacturing novel agents that can overcome the growing menace of bacteria resistant drugs and the attendant deaths.
Summary of Chapters
INTRODUCTION: Provides a theoretical overview of coordination compounds and Schiff bases, highlighting the necessity for new antimicrobial agents due to rising drug resistance.
EXPERIMENTAL METHODS: Details the chemical synthesis process of the ligand and metal complexes, as well as the specific instrumentation used for spectroscopic characterization and antimicrobial testing.
RESULTS AND DISCUSSION: Presents the findings from FTIR and UV/VIS spectroscopy, along with an analysis of the zone of inhibition and MIC data for the tested microorganisms.
CONCLUSION: Summarizes the study's findings, affirming that the synthesized Ni(II) complexes show superior inhibitory properties and potential for therapeutic use.
Keywords
Schiff base, Metal complexes, Coordination compounds, Antimicrobial activity, Spectroscopic characterization, FTIR, UV/VIS spectroscopy, Antibiotic resistance, Minimum Inhibitory Concentration, Zone of inhibition, o-phenylenediamine, m-hydroxybenzaldehyde, Co(II), Ni(II), Bio-inorganic chemistry.
Frequently Asked Questions
What is the fundamental focus of this scientific paper?
The paper focuses on the synthesis and characterization of new Schiff base metal complexes and an investigation into their antimicrobial potential.
What are the primary thematic areas explored in this work?
The work covers bio-inorganic chemistry, ligand synthesis, spectroscopic analysis (FTIR, UV/VIS), and microbiological assays to determine antibiotic efficacy.
What is the central research objective?
The objective is to synthesize novel Co(II) and Ni(II) Schiff base complexes and evaluate their capability to inhibit the growth of selected pathogenic microorganisms.
Which scientific methods are employed?
The study utilizes condensation reactions for synthesis, FTIR and UV/VIS spectroscopy for structural identification, and the broth dilution and Kirby-Bauer zone of inhibition methods for biological testing.
What does the main body of the work address?
It covers the systematic synthesis of the ligand, the spectroscopic verification of the metal-ligand coordination, and the statistical recording of inhibition zones and MIC values.
Which keywords best characterize this research?
Key terms include Schiff base, metal complexes, antimicrobial activity, MIC, bio-inorganic chemistry, and coordination compounds.
Why were Co(II) and Ni(II) chosen as metal centers for these complexes?
These metals were selected to study the influence of metal coordination on the biological activity of the Schiff base ligand, specifically aiming to enhance antimicrobial efficacy through coordination via the nitrogen atom.
How does the Ni(II) complex compare to the Co(II) complex and the free ligand?
The study found that the synthesized Ni(II) complex exhibited better bactericidal activity and overall performance compared to the Co(II) complex and the uncomplexed Schiff base.
What significance do the MIC values have for the reported results?
The MIC values quantify the potency of the agents; the results indicate that lower MIC scores, as seen with the Ni(II) complex, correspond to more effective antimicrobial inhibition of the test organisms.
- Quote paper
- Chibuzo Nnyigide (Author), 2019, Antimicrobial Properties of some Synthesized Schiff Base Metal Complexes, Munich, GRIN Verlag, https://www.grin.com/document/494076
