Tosyl-carrageenan/alginate composite adsorbent for removal of Pb2+ ions from aqueous solutions.

The current study effectively designed novel cross-linked tosyl-carrageenan/alginate (Ts-Car/Alg) beads to remove Pb2+ ions from their aqueous solutions. To confirm the structure of the produced matrix, characterization methods such as XRD, SEM, FTIR, and EDX were used. Batch experiments were employed in order to further evaluate the adsorption efficiency of Pb2+ ions. Additionally, various variables, including contact time, solution pH, adsorbent dosage, and initial concentration of Pb2+ ions were investigated using atomic absorption. The results of this study showed that the adsorption equilibrium increased as Pb2+ ions concentration increased at pH = 5.3 after a contact time of 120 min, with 0.3 g of Ts-Car/Alg that having the best adsorption capacity at 74 mg/g. The adsorption progression was further examined using the kinetic and isothermal models. With a correlation coefficient of 0.975, the Freundlich model was thought to better fit Pb2+ ions adsorption from the isotherm investigation. Also, the adsorption kinetics were investigated using a pseudo-second-order model with 1/n ratio of 0.683. This Ts-Car/Alg adsorbent is regarded as an effective candidate to be used for water treatment because the reusability process of produced beads was successfully completed twice, and the adsorbent maintained its ability to remove Pb2+ ions. The prepared Ts-Car/Alg beads are therefore excellent candidates to be used as potent Pb2+ ions adsorbents from their aqueous solutions. The Ts-Car/Alg beads' regeneration and reusability investigation for the removal of heavy metal ions was completed in at least two successful cycles.

Eco-friendly and biodegradable sodium alginate/quaternized chitosan hydrogel for controlled release of urea and its antimicrobial activity.

Hydrogels could be employed in agriculture for efficient management of water and controlled-release urea (CRU). This study aimed to synthesize a superabsorbent hydrogel for CRU by cross-linking sodium alginate (Alg) and N-(2-hydroxy-3-trimethyl ammonium) propyl chitosan chloride (HTACC). The hydrogel structure was characterized by various techniques, and the urea loading and releasing behaviors of the synthetic hydrogels were investigated. The results revealed that the maximum urea loading ranged between 107 and 200%, and that the urea loading kinetics fitted with Langmuir model followed by the Freundlich model. The urea release behavior reached equilibrium after 30 days and urea releasing kinetics fitted with the zero-order and Higuchi models. The synthesized hydrogels exerted significant antimicrobial activities and molecular docking showed their binding affinity toward glucosamine-6-phosphate synthase, ß-lactamase II, TraR binding site and nucleoside diphosphate kinase. In conclusion, these Alg/HTACC hydrogels showed swelling, urea release, and antimicrobial properties suitable to meet the plant requirements and produce economic and environmental benefits.

One-pot green synthesis of antimicrobial chitosan derivative nanocomposites to control foodborne pathogens.

Food contamination by foodborne pathogens is considered a serious problem worldwide. This study aimed to show the efficacy of the one-pot green biosynthesis of nanocomposites as effective antimicrobial agents based on a water-soluble biodegradable polysaccharide and silver nitrate (AgNO3). Silver (Ag) nanoparticles were synthesized using different concentrations of AgNO3 solution (1, 2, and 3 mM) in the presence of N-quaternized chitosan and N,N,N-trimethyl chitosan chloride (TMC) as both a reducing and stabilizing agent. In addition, the structure of TMC/Ag nanocomposites was confirmed using different analytical tools including FTIR, UV-Vis, XRD, HR-TEM, FE-SEM, and EDX techniques. The FTIR spectra and UV-Vis spectra showed the main characteristic absorption peaks of Ag nanoparticles. In addition, FE-SEM images showed the formation of spherical bead-like particles on the surface of TMC. Correspondingly, the EDX spectrum showed a peak for silver, indicating the successful synthesis of Ag nanoparticles inside the TMC chains. Moreover, HR-TEM images exhibited the good distribution of Ag nanoparticles, which appeared as nano-spherical shapes. The antimicrobial activity of TMC/Ag nanocomposites was examined against three foodborne pathogens, including Salmonella Typhimurium as a Gram-negative bacterium, Bacillus subtilis as a Gram-positive bacterium and Aspergillus fumigatus as a fungus. The results showed that TMC/Ag nanocomposites had better antimicrobial activity compared with TMC alone and their antimicrobial activity increased with an increase in the concentration of Ag. The results confirmed that the TMC/Ag nanocomposites can be potentially used as an effective antimicrobial agent in food preservation.

Development of antibacterial carboxymethyl cellulose/chitosan biguanidine hydrochloride edible films activated with frankincense essential oil.

This study aims to prepare binary edible films made from carboxymethyl cellulose (CMC) and chitosan biguanidine hydrochloride (CBg) activated with frankincense oil (FO). The interactions between CMC, CBg and FO were confirmed by FTIR. XRD showed that the addition of FO led to decreasing the crystallinity of CMC/CBg films. The water vapour permeability was reduced upon increasing the FO content. The presence of FO made the films brighter and didn't change their transparency as detected from the color measurements. The films exhibited better mechanical properties in the presence of FO as detected from the improved values of both tensile strength and elongation at break. The prepared films exhibited excellent antibacterial activity especially at high content of FO (5%). CMC/CBg/FO films might be used potentially in the production of edible films due to their excellent physical and antibacterial properties.

Crystal violet dye removal using crosslinked grafted xanthan gum.

As water is the most important source for survival for all individuals around the world, water pollution via synthetic toxic dyes and microorganisms is considered as a serious worldwide environmental problem. The present work aimed to synthesize crosslinked grafted xanthan gum (XG) films with poly (N-vinyl imidazole), PVI, for both removing crystal violet (CV) dye and inhibiting Escherichia coli (E. coli) growth. XG-grafted-PVI was prepared using potassium persulfate as an initiator to give different percentage of graft yield and using N, N'-methylene bisacrylamide (MBA) as a crosslinking agent. The structure of grafted XG films was elucidated via various analysis tools including FTIR, XRD, FE-SEM and EDX. Results of CV adsorption studies showed that maximum CV removal was 99.7% (625 mgg-1) which was achieved at: 95% GY, 2.5% MBA, 40 mg of adsorbent into 50 mL of 500 mgL-1 CV dye solution, pH 7, temperature (30 °C) and adsorption time (7 h). Also, results fitted well with Langmuir isotherm model. Moreover, pseudo-first order and intraparticle diffusion model participated in the mechanism of CV adsorption on grafted XG surface, in addition to its efficient recycling ability. Furthermore, antibacterial activities results of crosslinked grafted XG revealed their high inhibiting effect for E.coli growth.

Encapsulation of bovine serum albumin within novel xanthan gum based hydrogel for protein delivery.

Aim of the present study is to investigate synthesis of novel hydrogel as a potential protein carrier, intended for controlled release formulation. The hydrophilic bovine serum albumin (BSA) was chosen as a model protein to be encapsulated within xanthan gum (XG)/poly (N­vinyl imidazole (PVI) hydrogel. Both XG/PVI hydrogel and XG/PVI/BSA matrix structures were elucidated via different analysis tools such as FTIR, XRD, FE-SEM and EDX. Both BSA loading and release profiles were determined. Cytotoxicity of XG/PVI hydrogel was investigated against normal cell line (VERO cells). The obtained results revealed that % Drug (BSA) loading (% DL) and Encapsulation Efficiency (% EE) increased with increasing both gelation time and loaded BSA concentration, while %DL and %EE decreased with increasing the polymer concentration. The maximum value of %DL and %EE was 59.50% and 99.17%, respectively. Results of in-vitro BSA release in PBS showed that increase in the polymer (XG and PVI) concentrations led to increase in BSA release. Kinetic studies of the in-vitro release of BSA from XG/PVI/BSA matrix followed non-Fickian and case II transport mechanism. Moreover, Cytotoxicity results showed good biocompatibility of this novel hydrogel. SDS-PAGE analysis confirmed that the structural integrity of BSA was not affected by the encapsulation or release conditions. Consequently, this novel hydrogel can be used as an efficient BSA carrier for protein delivery.

Novel biodegradable and antibacterial edible films based on alginate and chitosan biguanidine hydrochloride.

Novel bioactive edible films based on sodium alginate (A) and chitosan biguanidine hydrochloride (CG) with different weight percents were successfully prepared. 13C NMR and 1H NMR confirmed the successful guanidylation of chitosan. Fourier transform infrared confirmed the successful reaction between CG and A. The interaction between CG and A was confirmed through the reduction of the crystalline peaks of both CG and A as detected from their wide-angle X-ray diffraction. Thermogravimetric analysis confirmed that CG enhanced the thermal stability of films as detected from the calculated integral procedure decomposition temperature (IPDT) values. CG incorporation improved the mechanical properties of dry and wet samples. A/CG films exhibited a reduced water vapor permeability and good color properties. The antibacterial study proved that the prepared films showed a remarkable antibacterial killing ability. These results revealed that A/CG films could be an alternative candidate to be used as antibacterial edible films in food industries.

Synthesis of novel grafted hyaluronic acid with antitumor activity.

In our study, we aimed to synthesize novel grafted hyaluronic acid with cationic biodegradable polymer, poly (N-vinyl imidazole) (PVI), through free radical polymerization using potassium persulfate as initiator. The effect of various grafting factors including initiator and monomer concentrations, reaction time and temperature was studied on the percentage of grafting parameters such as; graft yield (% GY), grafting efficiency (% GE) and amount of homopolymer formation (% H). Maximum grafted HA was% GY = 235% and%GE = 83% obtained on optimum conditions at [In] = 17.5 mmol L-1, [M] = 1.25 mol L-1, Temp. = 50 °C, time = 1.5 h and [HA] = 0.025 mol L-1. The structure of grafted HA (HA-g-PVI) was elucidated via various analysis tools such as; elemental analyses, FTIR, 1H NMR, XRD, TGA and Field emission scanning electron microscopy (FE-SEM). Hepatic and breast cancers are two common cancer types threatening people worldwide, so, the antitumor activity of two grafted HA samples (% GY = 155% and 235%) was studied against hepatic cancer (HepG-2) and breast cancer cell lines (MCF-7) compared to unmodified HA and PVI. The results showed that antitumor activity of grafted samples was more than unmodified HA and increased with increasing the grafting percentage of PVI onto HA chains, also, the antitumor activity of tested samples against HepG-2 cell lines was higher than MCF-7 cell lines.

Chitosan nanoparticles/cellulose nanocrystals nanocomposites as a carrier system for the controlled release of repaglinide.

The aim of the present work was to study the use of cellulose nanocrystals (CNC) and chitosan nanoparticles (CHNP) for developing controlled-release drug delivery system of the anti-hyperglycemic drug Repaglinide (RPG). CNC was isolated from palm fruit stalks by sulfuric acid hydrolysis; the dimensions of the isolated nanocrystals were 86-237 nm in length and 5-7 nm in width. Simple and economic method was used for the fabrication of controlled release drug delivery system from CNC and CHNP loaded with RPG drug via ionic gelation of chitosan in the presence of CNC and RPG. The prepared systems showed high drug encapsulation efficiency of about ~98%. Chemical modification of CNC by oxidation to introduce carboxylic groups on their surface (OXCNC) was also carried out for further controlling of RPG release. Particles size analysis showed that the average size of CHNP was about 197 nm while CHNP/CNC/RPG or CHNP/OXCNC/RPG nanoparticles showed average size of 215-310 nm. Compatibility studies by Fourier transform infrared (FTIR) spectroscopy showed no chemical reaction between RPG and the system's components used. By studying the drug release kinetic, all the prepared RPG formulations followed Higuchi model, indicating that the drug released by diffusion through the nanoparticles polymeric matrix.

Green synthesis of antimicrobial and antitumor N,N,N-trimethyl chitosan chloride/poly (acrylic acid)/silver nanocomposites.

The present study is imported to solve two critical problems we face in our daily life which are microbial pollution and colon cancer. One pot green synthesis of a water soluble polyelectrolyte complex (PEC) between cationic polysaccharide as N,N,N-trimethyl chitosan chloride (TMC) and anionic polymer as poly (acrylic acid) (PAA) in presence of silver nanoparticles to yield (TMC/PAA/Ag) nanocomposites with different Ag weight ratios. Structure of TMC, PAA and TMC/PAA (PEC) were proved via different analysis tools. TMC/PAA and its Ag nanocomposites are used as antimicrobial agents against different pathogenic bacteria and fungi to solve microbial pollution. TMC/PAA-Silver nanocomposites had the highest antimicrobial activity which increases with increasing Ag %. Cytotoxicity data confirmed also that TMC/PAA/Ag (3%) had the most cytotoxic effect (the less cell viability %) towards colon cancer. TMC/PAA (PEC) was formed through electrostatic interactions between N-quaternized (-N+R3) groups in TMC and carboxylate (-COO-) groups in PAA.

Synthesis, characterization and antimicrobial activity of Schiff bases modified chitosan-graft-poly(acrylonitrile).

Graft copolymerization of chitosan (Ch) with acrylonitrile (AN) prepared by free radical polymerization using potassium persulfate (PPS) as initiator. Optimization of Graft copolymerization of acrylonitrile on to chitosan was performed by studying the main parameters that affecting the grafting process such as initiator and monomer concentrations, reaction time and temperature of the polymerization process to study their influence on percent grafting (G%), grafting efficiency (GE%) and percent homopolymer (H%). Modification of grafted chitosan was done by Schiff's base derivatives using different aldehydes. They are characterized by FT-IR, X-ray diffraction, thermal analysis and scanning electron microscope. Their antibacterial activities against Streptococcus pneumonia (RCMB 010010), Staphylococcus aureus (RCMB 010028), as Gram-positive bacteria and Escherichia coli (RCMB 010052) as Gram-negative bacteria and the antifungal activity against Aspergillus fumigatus (RCMB 02568), Candida albicans (RCMB 05036) and Geotricum candidum (RCMB 05097) were examined using the diffusion agar technique. The obtained data proved that modified chitosan by grafting show better antimicrobial activities than Chitosan. Also Schiff base derivatives showed better antimicrobial activities than grafted chitosan.

Synthesis of novel biodegradable antibacterial grafted xanthan gum.

Xanthan gum (XG) is natural polysaccharides used in food industries as stabilizers and thickener agents. The problem is that some food products are found to be contaminated by pathogenic bacteria such as Escherichia coli (E. coli) and Staphyloccus aureus (S. aureus) that reduce their shelf life. This research aims to synthesize biodegradable antibacterial XG-grafted-poly(N-vinyl imidazole) PVI and the effect of reaction parameters were studied on grafting yield (G), grafting efficiency (GE), total conversion (TC) and homopolymer (H) %. XG-g-PVI was characterized via various analysis tools. Thermal analysis showed that grafted XG was more thermally stable than unmodified XG and their stability increased with increasing PVI%. XG-g-PVI was acting as antibacterial agent against (E. coli and S. aureus) bacteria that cause food borne diseases. Their activity increases with increasing grafting yield%. Surface morphology showed change from irregular lobules shape in XG to smooth surface in its graft with PVI.

Synthesis, characterization and antimicrobial activity of biguanidinylated chitosan-g-poly[(R)-3-hydroxybutyrate].

Chitosan biguanidine hydrochloride (ChG) and low molecular weight poly[(R)-3-hydroxybutyrate] (PHB) were successfully prepared to overcome the solubility problem of chitosan and PHB and also to enhance antimicrobial activity of chitosan. The graft copolymers based on ChG and PHB (ChG-grafted PHB) were then prepared via condensation reaction of the carboxylic groups of PHB with the amino groups of ChG. These graft copolymers swell in water. The prepared graft copolymers were characterized by FTIR, 1H NMR, X-ray diffraction (XRD) and thermal analyses (TGA and DSC). TGA and DSC results revealed that the thermal stability and crystallinity of the graft copolymers were found to increase as the content of PHB increased. The antimicrobial activity of both ChG and ChG-grafted PHB, against Streptococcus pneumoniae, Bacillus subtilis, Escherichia coli (as examples of bacteria) and Aspergillus fumigatus, Geotricum candidum and Syncephalastrum recemosum (as examples of fungi), were tested. Among them, ChG and ChG-grafted PHB with the highest grafting percent investigated showed to possess relatively higher antimicrobial activity with low MIC values in the range of 0.49-3.90µgmL-1.

Cytotoxicity and metal ions removal using antibacterial biodegradable hydrogels based on N-quaternized chitosan/poly(acrylic acid).

Physically crosslinked hydrogels resulted from interaction between N,N,N-trimethyl chitosan chloride (N-Quaternized Chitosan) (NQC) and poly(acrylic acid) (PAA) were synthesized in different weight ratios (3:1), (1:1) and (1:3) taking the following codes Q3P1, Q1P1 and Q1P3, respectively. Characterization of the mentioned hydrogels was done using several analysis tools including; FTIR, XRD, SEM, TGA, biodegradation in simulated body fluid (SBF) and cytotoxicity against HepG-2 liver cancer cells. FTIR results proved that the prepared hydrogels were formed via electrostatic and H-bonding interactions, while XRD patterns proved that the prepared hydrogels -irrespective to their ratios- were more crystalline than both matrices NQC and PAA. TGA results, on the other hand, revealed that Q1P3 hydrogel was the most thermally stable compared to the other two hydrogels (Q3P1 and Q1P1). Biodegradation tests in SBF proved that these hydrogels were more biodegradable than the native chitosan. Examination of the prepared hydrogels for their potency in heavy metal ions removal revealed that they adsorbed Fe (III) and Cd (II) ions more than chitosan, while they adsorbed Cr (III), Ni (II) and Cu (II) ions less than chitosan. Moreover, testing the prepared hydrogels as antibacterial agents towards several Gram positive and Gram negative bacteria revealed their higher antibacterial activity as compared with NQC when used alone. Evaluating the cytotoxic effect of these hydrogels on an in vitro human liver cancer cell model (HepG-2) showed their good cytotoxic activity towards HepG-2. Moreover, the inhibition rate increased with increasing the hydrogels concentration in the culture medium.

Synthesis, characterization, and biological activity of cross-linked chitosan biguanidine loaded with silver nanoparticles.

Chitosan biguanidine hydrochloride (ChG) and glutaraldehyde cross-linked chitosan biguanidine (CChG) were synthesized and characterized by Fourier transform infrared spectroscopy, 1H NMR and 13C NMR, X-ray diffraction, scanning electron microscopy (SEM) and thermal analyses (TGA and DTA). The results showed that ChG and CChG had a more amorphous structure than that of chitosan, and their thermal stability were slightly lower than that of chitosan. Colloidal silver nanoparticles (AgNPs) were prepared using borohydride reduction method and then investigated as fillers in partially cross-linked chitosan biguanidine. The obtained nanoparticles were uniform and spherical with average size of 9.6 ± 0.5 nm. The prepared CChG/AgNPs composites were characterized for their morphology, thermal properties, cytotoxicity and antimicrobial activity. The SEM images showed that the AgNPs are well imbedded in the CChG matrix. The thermal stability of CChG was improved with incorporation of AgNPs. The CChG and CChG/AgNPs showed less cytotoxicity to breast cancer cells (MCF-7). Compared with chitosan and CChG, the ChG and CChG/AgNPs showed better antimicrobial activity against Streptococcus pneumoniae and Bacillus subtilis as Gram-positive bacteria, Escherichia coli as Gram-negative bacteria and Aspergillus fumigatus, Geotricum candidum and Syncephalastrum recemosum as fungi.

Synthesis, characterization and application of biodegradable crosslinked carboxymethyl chitosan/poly(vinyl alcohol) clay nanocomposites.

Crosslinked poly(vinyl alcohol) (PVA)/carboxymethyl chitosan (CMCh) nanocomposites were synthesized using terephthaloyl diisothiocyanate crosslinker, in the presence of montmorillonite (MMT), in different ratios of the two matrices. Characterization of nanocomposites was performed using different analyses. Swelling behavior was studied in different buffered solutions. It was found that formation of crosslinked CMCh/PVA hydrogels increased the swellability. Metal ion adsorption has also been investigated. The results indicated that crosslinked CMCh adsorbs various metal ions much more than non crosslinked CMCh. Antimicrobial activity was examined against Gram positive bacteria, against Gram negative bacteria, and also against fungi. Results indicated that most of these nanocomposites exhibited good antimicrobial potency. Degradation study was carried out in Simulated Body Fluid (SBF) for different time periods in order to find out degradation index (Di). Results showed that weight loss of most of the nanocomposites increased as a function of incubation time.

Synthesis, characterization and applications of N-quaternized chitosan/poly(vinyl alcohol) hydrogels.

Hydrogels composed of N-quaternized chitosan (NQC) and poly(vinyl alcohol) (PVA) in different weight ratios (1:3), (1:1) and (3:1) chemically crosslinked by glutaraldehyde in different weight ratios ­ 1.0 and 5.0% ­ have been prepared. The prepared hydrogels were characterized via several analysis tools such as: Fourier transform IR (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM) and thermogravimetric analysis (TGA). Different applications have been done on NQC/PVA hydrogels including; metal ions uptake, swellability in different buffer solutions (pH: 4, 7 and 9), swellability and degradation studies in simulated body fluid (SBF) solutions and antimicrobial activity towards bacteria and fungi. The results indicated that crosslinked NQC/PVA hydrogels with glutaraldehyde (GA) are more thermallystable than non crosslinked hydrogels, NQC/PVA hydrogels swell highly in different buffer solutions as PVA content increases and the antimicrobial activity of NQC/PVA hydrogels is higher than NQC itself.

Synthesis, characterization and biological activity of Schiff bases based on chitosan and arylpyrazole moiety.

The Schiff bases of chitosan were synthesized by the reaction of chitosan with 3-(4-substituted-phenyl)-1-phenyl-1H-pyrazole-4-carbaldehyde. The structure of the prepared chitosan derivatives was characterized by FT-IR spectroscopy, elemental analysis, and X-ray diffraction studies and thermogravimetric analysis (TG). The results show that the specific properties of Schiff bases of chitosan can be altered by modifying the molecular structures with proper substituent groups.TG results reveal that the thermal stability of the prepared chitosan Schiff bases was lower than chitosan. The activation energy of decomposition was calculated using Coats-Redfern model. The antimicrobial activity of chitosan and Schiff bases of chitosan were investigated against Streptococcus pneumonia, Bacillis subtilis, Escherichia coli (as examples of bacteria) and Aspergillus fumigatus, Geotricum candidum and Syncephalastrum recemosum (as examples of fungi). The results indicated that the antimicrobial activity of the Schiff bases was stronger than that of chitosan and was dependent on the substituent group. The activity of un-substituted arylpyrazole chitosan derivative toward the investigated bacteria and fungi species was better than the other derivatives.

Synthesis and characterization of antimicrobial crosslinked carboxymethyl chitosan nanoparticles loaded with silver.

Carboxymethyl chitosan (CMCh)-silver nanoparticle (Ag) hydrogels with high antibacterial activity against three Gram +ve bacteria (Staphylococcus aureus, Bacillus subtilis and Streptococcus faecalis), three Gram -ve bacteria (Escherichia coli, Pseudomonas aeruginosa and Neisseria gonorrhoeae) and a Candida albicans fungus were prepared. The in situ preparation reaction involved crosslinking of CMCh with epichlorohydrin in alkaline medium containing silver nitrate to yield silver nanoparticles loaded CMCh hydrogel giving pale brown or darker hydrogels when the silver content increases. FTIR spectroscopy, SEM and TEM were done for the prepared hydrogels. Silver nanoparticles hydrogels exhibited higher antimicrobial activity than virgin CMCh. TEM analysis showed the small size of the prepared hydrogels to be in the range of 9-16nm in size.

Quaternized N-substituted carboxymethyl chitosan derivatives as antimicrobial agents.

Introduction of quaternary ammonium moieties into N-substituted carboxymethyl chitosan (N-substituted CMCh) derivatives enhances their biological activity. Several derivatives of CMCh having a variety of N-aryl substituents bearing either electron-donating or electron withdrawing groups have been synthesized by the reaction between amino group of CMCh with various aromatic aldehydes under acidic conditions, followed by reduction of the produced Schiff base derivatives with sodium cyanoborohydride. Each of the reduced derivatives was further quaternized using N-(3-chloro-2-hydroxy-propyl)trimethylammonium chloride (Quat-188). The resulting quaternized materials were characterized by FTIR and (1)H NMR spectroscopy. Their antibacterial activities against Streptococcus pneumoniae (S. pneumonia, RCMB 010010), Bacillis subtilis (B. subtilis, RCMB 010067), as Gram positive bacteria and against Escherichia coli (E. coli, RCMB 010052) as Gram negative bacteria and their antifungal activities against Aspergillus fumigatus (A. fumigates, RCMB 02568), Geotricum candidum (G. candidum, RCMB 05097), and Candida albicans (C. albicans, RCMB 05031) were examined using agar disk diffusion method. The results indicated that all the quaternized derivatives showed better antimicrobial activities than that of CMCh. These derivatives are highly potent against Gram positive bacteria compared to Gram negative bacteria. This is illustrated for example as the values of minimum inhibitory concentration (MIC) of Q4NO2-BzCMCh against B. subtilis and S. pneumonia were 6.25 and 12.5 µg/mL, respectively corresponded to 20.0 µg/mL against E. coli. The antimicrobial activity of quaternized N-aryl CMCh derivatives affected by not only the nature of the microorganisms but also by the nature, position and number of the substituent groups on the phenyl ring. Thus while the derivatives with groups of electron withdrawing nature show higher inhibition zone diameter and lower MIC values relative to that of those having electron-donating nature, the non-substituted derivative lies between these two extremes. Antibacterial activities of Q4NO2-BzCMCh, Q3Cl-BzCMCh and Q3Br-BzCMCh against E. coli are nearly equivalent to that of the standard drug Gentamycin. Q3Br-BzCMCh emerged almost equivalent antibacterial activity to Ampicillin against S. pneumonia.