Antimicrobial Activity Studys Of Schiff Base Derived From Para-Anisaldehyde

ABSTRACT

Schiff bases was prepared via condensation of para-anisaldehyde and 2-aminothiophenol, recrystallized from ethanol, washed and dried. The Schiff base was characterised using spectro-analytic methods such as melting point determination, solubility test, ultraviolet-visible spectroscopy and Infrared spectroscopy. The result of the Infrared revealed that there was a bathochromic/Hypochromic shift at 1521 indicating the involvement of the azomethine group. The Schiff base was screened using Agar Well Technique for it’s antibacterial and antifungi activity against bacteria species staphylococcus aureus and streptococcus, and fungi species Candida albicans and Aspergillus flavus. The antimicrobial activity data shows that the Schiff base was potent as follows ; Streptococcus > Condida albicans > Aspergillus flavus > Staphylococcus aureus = Escherichia coli = Salmonella species.

CHAPTER ONE

1.1 BACKGROUND OF STUDY

Coordination Chemistry is the study of chemical compounds (coordination complexes) consisting of a central atom or ion, which is usually metallic and is called the coordination centre, and a surrounding array of bound molecules or ions, that are  known as ligands or complexing agents.^[1][2][3]

Many metal-containing compounds, especially those that include transition metals (elements like titanium that belong to the periodic table’s d-block), are coordination complexes.^[4]

One of the examples of the formation of a coordination compound can be shown from the condensation of amine with aldehydes or ketones to form a schiff base, or even a transition metal bonding with a Schiff base ligand, to form a covalent bond.

1.2 APPLICATION AND IMPORTANCE OF COORDINATION CHEMISTRY

As metals only exist in solution as coordination complexes, it follows then that this class of compounds is useful in a wide variety of ways such as the bioinorganic chemistry or bioorganometallic chemistry where coordination complexes serve either structural or catalytic functions. An estimated 30% of proteins contain metal ions. Examples include the intensely colored vitamin B12, the heme group in hemoglobin, carboxypeptidase, a hydrolytic enzyme important in digestion. Another complex ion enzyme is catalase, which decomposes the cell’s waste hydrogen peroxide. Synthetic coordination compounds are also used to bind to proteins and especially nucleic acids (e.g. anticancer drug cisplatin).

Homogeneous catalysis also has a major application of coordination compounds for the production of organic substances.

1.3 SCHIFF BASE LIGAND

A Schiff base (named after Hugo Schiff) is a compound with the general structure R₁R₂C=NR₃ (R₃ = alkyl or aryl, but not hydrogen). They can be considered a sub-class of imines, being either secondary ketimines or secondary aldimines depending on their structure. The term is often synonymous with azomethine which refers specifically to secondary aldimines (i.e. R−CH=NR’ where R’ ≠ H)^[11].

This common feature determines the ability of Schiff bases to form complexes with transition metal ions . In these complexes, they function (like amines, amides and phosphines) as L-type ligands, that is, ligands containing two-electron donors, which do not undergo electron changes on their valence shells.

1.3.1 FORMATIONANDCHEMISTRY OF SCHIFF BASE

Schiff bases are common ligands in coordination chemistry prepared by the condensation reaction of certain aliphatic or  aromatic amines with  aromatic aldehydes.

The complex formation takes place by coordinating the d-block metal ion by the electron-donating ligand atom and serves to modify the steric and electronic surrounding of the metal. This leads to the stabilization and regulation of the reactivity of the metal ion, which is especially useful for less stable ions at higher oxidation states . Nitrogen, oxygen or sulfur atoms can participate in the coordination as donors. Multivalent Schiff base ligands eagerly form complexes: bidentate and tridentate with Co(II), Ni(II) ions, as well as four-dentate, highly stabilizing metal ions at various oxidation states, starting with divalent Ni(II), Cu(II), Pd(II) or tetravalent V(IV), Ti(IV), up to uranium U(III,IV,V). ^[13][14]

1.3.2 APPLICATION OF SCHIFF BASE AND METAL COMPLEXES

Metal complexes with these schiff bases have numerous applications, such as, in the treatment of cancer , as antibactericide agents , as antivirus agents , as fungicide agents , pain-relieving, antimicrobial, anticonvulsant and for other biological properties. Several applications have been related for these complexes in chemical analysis ,absorption and transport of oxygen , in pesticides  and heterogeneous and homogeneous catalysis for oxidation and polymerization of organic compounds .

Antibacterial Activity:-

Bacteria is the root cause of many infectious diseases and responsible for an increase in the mortality rate. There are different kinds of bacteria and they exhibit a lot of resistance to antibiotics. Schiff bases have emerged as promising antibacterial agents. For example, Mycobacterium can be effectively treated with N- (salicylidene) -2- hydroxyaniline.^[15][16]

Antifungal Activity:-

Schiff bases with a 2,4-dichloro-5-fluorophenyl moiety have been proven to restrict the growth of fungi like Aspergillus flavus, Aspergillus fumigatus, Trichophyton mentagrophytes, and Penicillium marneffei. ^[17]

Schiff Base Complexes as Catalysts:-

Many Schiff base complexes of metal ions show high catalytic activity and play a significant role in various reactions to enhance their yield and product selectivity. The convenient route of synthesis and thermal stability of Schiff base ligands have contributed significantly for their possible applications in catalysis as metal complexes

Schiff base complexes of transition metal ions are efficient catalysts for both homogeneous and heterogeneous reactions and the activity of these complexes varies with the type of ligands, coordination sites and metal ions. Chiral Schiff base complexes are more choosy in various reactions such as oxidation, hydroxylation, aldol condensation and epoxidation.^[18][19][20]

1.3.3 ANTIMICROBIAL STUDIES/ ACTIVITIES

Microbial resistance to current drugs associated with food spoilage and complications in diseases’ treatment have resulted in increased mortality rate globally. Schiff bases are an important versatile class of organic compounds with notable pharmacological properties for various industrial applications. They are usually synthesized from a condensation reaction between a primary amine and a carbonyl. They have a wide range of activities against microbes and demonstrate good antimicrobial activity against fungi ,bacteria ,parasites, and viruses.The antimicrobial activity of Schiff base ligands is usually better

Upon metal complexation as a result of their chelating behaviour. The synthesis of Schiff bases and their metal complexes are well documented. Therefore, it is important to categorize and compile them according to their biological significance. In this review, the antibacterial, antifungal, antiparasitic and Antiviral activity of some selected heterocyclic Schiff bases and their metal complexes are discussed.^[21]

1.4 PARA-ANISALDEHYDE

Para-anisaldehyde ( 4-Anisaldehyde or p-Anisaldehyde), is an organic compound with the formula CH₃OC₆H₄CHO. The molecule consists of a benzene ring with a formyl and a methoxy group. It is a colorless liquid with a strong aroma and It provides sweet, floral and strong aniseed odor. Two isomers of 4-anisaldehyde are known, ortho-anisaldehyde and meta-anisaldehyde. They are less commonly encountered.

Figure 1:- Structure of para-anisaldehyde

Anisaldehyde is prepared commercially by oxidation of 4-methoxytoluene (p-cresyl methyl ether) using manganese dioxide to convert a methyl group to the aldehyde group. It can also be produced by oxidation of anethole, a related fragrance that is found in some alcoholic beverages, by oxidative cleavage of an alkene. ^[22]

1.4.1 APPLICATION OF PARA-ANISALDEHYDE

Being structurally related to vanillin, Para- anisaldehyde (4-anisaldehyde) is a widely used in the fragrance and flavor industry. It is used as an intermediate in the synthesis of other compounds important in pharmaceuticals and perfumery. The related ortho isomer has a scent of licorice.

A solution of para-anisaldehyde in acid and ethanol is a useful stain in thin layer chromatography.Different chemical compounds on the plate can give different colors, allowing easy distinction.

DNA BREAKAGE:- Anisaldehyde in combination with copper (II) can induce single- and double-strand breaks in double stranded DNA.^[23]

1.5 – AMINOTHIOPHENOL

2-Aminothiophenol is an organosulfur compound with the formula C₆H₄(SH)(NH₂). It is a colorless oily liquid, although impure samples can be deeply colored. It is soluble in organic solvents and in basic water.

2-Aminothiophenol is a precursor to benzothiazoles, some of which are bioactive or are commercial dyes. Isomers of aminothiophenols include 3-aminothiophenol and 4-aminothiophenol.

Figure 2:- Structure of aminothiophenol

1.5.1 SYNTHESIS OF 2- AMINOTHIOPHENOL

2-aminothiophenol can prepared in two steps, starting with the reaction of aniline with carbon disulfide followed by hydrolysis of the resulting mercaptobenzothiazole. It can also obtained by zinc reduction of

2-nitrobenzenesulfonyl chloride.^[24]

1.6 SIGNIFICANCE OF STUDY

Shiff bases  are flexible compound synthesised from the condensation of Para-anisaldehyde and 2- aminothiophenol, they can used as empirical studies for other researchers & also elaborated on the industries’ applications, such as the food industry, analytical application,  energy storage, environmental, chemo-sensing and biomedical applications.

1.7 STATEMENT OF PROBLEM

However, there is a knowledge gap regarding the specific properties and anti-microbial effects on Schiff bases derived from specific combination of para-anisaldehyde and 2-aminothiophenol. Therefore, this study aim to address this gap by exploring the synthesis, characterization and anti-microbial activities of Schiff base compound derived from these two starting materials.

1.8 JUSTIFICATION OF STUDY

Schiff base have many applications in various fields of Chemistry such as electrochemistry, catalysis, organic syntheses and more importantly medicinal values. They are important intermediates in a number of enzymatic reactions involving interactions of the Amino group of an enzyme with a carbonyl group of substance

Due to the recent discovery that is being made in schiff bases and its anti-microbial activities, this work is focused on synthesis of para-anisaldehyde and 2-aminothiophenol for more insight and understanding of its properties towards some biological activities using antimicrobial analysis,uv and IR spectroscopy analysis.

1.9 SCOPE OF STUDY

1. Synthesis of Schiff base ligand from Para-anisaldehyde and

2-aminothiophenol.

2. Characterization using spectroanalytical techniques.
3. Anti-microbial analysis of the Schiff base. Using Well in Agar Technique

1.10 AIM AND OBJECTIVE OF STUDY

AIM:- This project work is aimed at synthesizing , characterizing using anti- spectroanalytical methods and antimicrobial analysis of para-anisaldehyde and 2-aminothiophenol.

OBJECTIVE OF STUDY

1. To synthesize Schiff base ligand derived from para-anisaldehyde and

2- aminothiophenol.

2.To characterize the Schiff base ligand

3.To carry out Antimicrobial analysis of the Schiff base ligand.

1.11 LIMITATIONS OF STUDY

1. Irregular availability of water made the research work stressful and consumed much time
2. Epileptic supply of power much funds was spent on purchase of petrol.

1.12 LITERATURE REVIEW

Huda S. Abood, Usama H. Ramadhan and Hussam Hamza synthesized two new Schiff bases were synthesized from 3-Phenyl-propenal (cinnamaldehyde) with amino acids (Tryptophan or Histidine) as ligands. Complexes synthesized from reaction of ligand with metal ion, copper sulphate were used for complexes preparation. The synthesized compounds identify by FT-IR and 1HNMR spectra. Inflammation was induced by injection of fresh hen egg albumin in mice paw. Anti-inflammatory activity was estimated by measured thickness of mice paw, the complex that contain tryptophan show activity against inflammation compare with aspirin, which is used as standard drug. The activity may be attributed to tryptophan ring in the complex.

Heba H. Sabah synthesised Schiff bases derived by condensation of 4,4` methylen-di-aniline different aldehydes such as Benzaldehyde, p-methoxy Benzaldehyde and p-chloro Benzaldehyde, P-methoxy Benzaldehyde and pChloro Benzaldehyde are reported. Spectroscopic techniques , including IR , 1HNMR were used to identify the products.

Radhika Pallikkavil, Muhammed Basheer Ummathur and Krishnannair Krishnankutty synthesised  Terephthalaldehyde on reaction with 2aminophenol and 2aminothiophenol yielded a new series of polydentate Schiff’s base ligands (H2L and H2L). Dibasic tetradentate coordination of the compounds in their [M2L2] complexes [M = Ni(II), Cu(II) and Zn(II)] has been established on the basis of analytical and spectral data.

Pages:  45

Category: Project

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Source: Imsuinfo

Material contains Table of Content, Abstract and References.