antibacterial activity

Butterfly pea flowers (Clitoria ternatea) are a natural source of quercetin, a flavonoid with various biological activities, including antioxidants, anti-inflammatory, and antibacterial properties. This study aims to determine the quercetin levels in butterfly pea flower extract and test its antibacterial activity against Escherichia coli and Staphylococcus aureus. Quercetin analysis using the HPLC method at a wavelength of 374 nm showed an average level of 42 ppm (4.2% w/w), with method validation including accuracy, precision, linearity (𝑟2=0.9959), and LOD and LOQ are 0.57 ppm and 1.91 ppm respectively. Antibacterial tests showed that butterfly pea flower extract inhibited the growth of E. coli and S. aureus with the largest zone of inhibition at a concentration of 30% of 10.27 ± 1.01 mm and 12.28 ± 0.09 mm, respectively. This activity is related to the quercetin content, which is known to work through mechanisms such as damaging bacterial cell walls and inhibiting biofilm formation. Due to this pharmacological potential, these flowers can be developed as a natural antibacterial agent in pharmaceutical and cosmetic applications.

This study investigates the potential of Coconut Seed Coat Ash (CSCA) as a sustainable and environmentally friendly green catalyst. CSCA was prepared by controlled combustion of coconut seed coat and husk at 500 °C in a muffle furnace, ensuring consistent results and complete combustion. The study highlights the advantages of using CSCA, including its low cost, abundance, and renewable nature, making it a promising catalyst for facilitating chemical reactions without being consumed. Utilizing CSCA at a concentration of 30 mmol/L, a series of 2-amino-4H-benzopyran derivative was synthesized through a reaction between aromatic aldehydes, dimedone, and malononitrile. This green approach proved cost-effective, practical, and efficient, offering high yields and simple work-up procedures. The synthesized compounds were characterized using IR spectroscopy, mass spectrometry (MS), proton nuclear magnetic resonance (¹H-NMR), and elemental analysis. Furthermore, the antimicrobial activity of the compounds was evaluated against bacterial strains (Staphylococcus aureus MCC 2010, Bacillus subtilis MCC 2010, Escherichia coli MCC 2412, and Pseudomonas aeruginosa MCC 2080) and yeast strains (Candida albicans MCC 1439 and Saccharomyces cerevisiae). The synthesized compounds exhibited notable spectral peaks in FTIR, ¹H-NMR, and UV analyses and demonstrated superior antibacterial and antifungal activities in vitro compared to standard antibiotics streptomycin and fluconazol.

This study reports the synthesis of new 1,3-oxazepine derivatives (S21-S30) by reacting hydrazones (Schiff bases) (S11-S20) with phthalic anhydride in dry benzene as the solvent. The hydrazones were prepared by reacting diphenyl acrylamide derivatives (S1-S10) with para-chloroaniline using ethanol as the solvent. The acrylamides were derived from para-substituted acetanilides treated with various para-benzaldehydes using ethanol as the solvent. All synthesized compounds have been characterized using UV-Visible and FT-IR spectroscopy. The structure of chemicals has been confirmed using proton and carbon nuclear magnetic resonance spectroscopy (1H-NMR and 13C-NMR). The purity of the synthesized chemicals was confirmed through Thin-Layer Chromatography (TLC). The antibacterial activity of the new compounds has been assessed against gram-positive bacteria (Streptococcus Pneumoniae and Staphylococcus Aureus) and gram-negative bacteria (Pseudomonas Aeruginosa and Escherichia Coli).  The results showed significant antimicrobial activity at varying concentrations, with compounds S23, S26, and S30 exhibiting the highest effectiveness attributed to the electron-withdrawing halogens present in their structures.

Wound infection can cause delayed wound healing, and due to the emergence of antibiotic resistance, treatment of wound infection has become less effective using conventional antibiotics. This has led to the search for an alternative treatment method, which ethnomedicine has proven to be promising. Thus, the antibacterial activity of Senna occidentalis leaf extract was evaluated against isolated bacteria from the wound of patients attending Kwararafa Hospital Wukari, Taraba State, Nigeria. A total of three (3) wounds were randomly swabbed. Bacteria were isolated and identified using standard microbiological procedures. The disk diffusion method was used to assess the antibacterial activity of the aqueous and methanolic extracts of Senna occidentalis leaf extract at different concentrations (20 mg/ml, 40 mg/ml, 60 mg/ml, 80 mg/ml, and 100 mg/ml). The bacteria pathogens isolated and identified are Staphylococcus spp. 3(37.5%), Klebsiella pneumonia 2(25%), Escherichia coli 2 (25%), and Pseudomonas aeruginosa 1(12.5%). The aqueous extract was not effective, while the methanolic leaf extract of the plant displayed promising antibacterial activity at all concentrations against all the bacterial isolates, with the highest zones of inhibition recorded at 100mg/mL, measuring 16±5.0mm, 18±5.0 mm, 20±5.0 mm, and 15±0.0 mm, for Staphylococcus spp., Klebsiella pneumonia, Escherichia coli, and Pseudomonas aeruginosa respectively. The result of this study supports the traditional use of Senna occidentalis in the treatment of wound infections.

Bis-phosphonic acid and bis-phosphonate derivatives are a diverse group of natural and synthetic compounds, they exhibit interesting physiological activities and are therefore considered as potential therapeutics in modern medicine. They have found applications as antibacterial, antiviral and as anti-osteoporosis drugs. The present work deals with the preparation of novel Schiff base derivatives linked to inorganic bis-phosphonate groups by reacting the parent compound: Bisphosphonic acid (4-aminophenyl) (hydroxyl) methylene (2) with a variety of aldehydes and ketones. The parent reactant and its condensation products (3a-3j) were identified by physical and spectroscopic techniques, namely; FT-IR, 1H-, 13C-, and 31P-NMR. The antibacterial activity of these derivatives were studied by disk diffusion method and found to possess high in vitro antimicrobial activity against gram-positive and gram-negative bacteria viz. Staphylococcus aureus, Bacillus anthraces, Escherichia coli and Acinetobacter species, referenced to azithromycin and levofloxacin.

Some amide derivatives of drugs containing a carboxyl group (Diclofenac¸ ketoprofen, oxaprozin, and naproxen) were prepared with one of the aniline derivatives. The effective method for preparing amides involves coupling amines with carboxylic acids utilizing dicyclohexylcarbodiimide (DCC) and 4-dimethylaminopyridine (DMAP) under ordinary temperature conditions. The antioxidant activity was evaluated with the 2X08 protein. The results of molecular docking confirmed the biological activity of the prepared compounds and derivative 3 (N-(4-chlorophenyl)-2-((2,6 dichlorophenyl)amino)benzamide) showed high inhibitory activity according to the (Phosphomolybdate assay) method. The other synthesized derivatives exhibited varying degrees of inhibition compared to ascorbic acid. Additionally, the antibacterial (Escherichia Coli) and antifungal (Candida albicans) activities of the prepared compounds were evaluated. The derivatives showed high to moderate activity compared to the standard references (cephalexin and fluconazole), with compound 2 showing significant activity against both bacteria and fungi. All the synthesized compounds were characterizedˮ using FT-IR, ¹H-NMR, 13C-NMR and molecular docking studies.

In the present study, the structural, antibacterial, and antioxidant properties of silver nanowires (AgNWs) synthesized by a bio-reduction method. Silver nitrate was used as a precursor and aqueous Brassica tournefortii leaves extract as a reducing and template. Silver nanowires were characterized by using XRD, FTIR, UV-Visible, and SEM techniques. XRD confirmed the crystalline and face-centered cubic nature of the AgNWs with an average crystallite size of 16-18 nm. FT-IR spectra confirmed the presence of polyphenols, which are responsible for the reduction of silver ions and the efficient stabilization of silver nanowires. According to the UV-Vis spectrum, the SPR absorption band of AgNWs was observed at 360 nm. The SEM survey shows the obtained nanowires' shape. Silver nanowires showed antibacterial activities especially against Pseudomonas aeruginosa and Streptococcus agalacteae, with respective diameters of inhibition zones (DIZ) measuring 21 mm and 18 mm, respectively. Furthermore, the minimum inhibitory concentration (MIC) of AgNWs against E. coli was determined to be 18.75 μg/mL. The AgNWs demonstrated robust antioxidant activity by ABTS-radical scavenging activity yielded IC50 value of 50.98 μg/mL. These findings strongly suggest the potential of Ag nanowires for various biomedical applications.

The discovery of a new class of two-dimensional (2D) materials known as MXene was a significant breakthrough. Due to its remarkable properties, it has sparked extensive discussion and enabled countless applications across various fields. Due to the toxic nature of HF acid used in the pioneered etching method for MXene synthesis, researchers have been proposing alternative etching strategies to prevent the toxicity associated with HF acid. In addition, various applications require MXene with specific properties such as termination groups, defects-free, and large or small flake sizes, as a result, this accounts for exploring and developing various strategies to achieve the desired properties. This mini-review provides an idea about the general overview of MXene, and synthesis strategies. It highlights multiple applications in biomedical technologies like antibacterial properties, radical scavenging, drug delivery, bone regeneration, etc. The unique features of MXene are the major reasons that attract its application in biomedical technologies even though biomedical applications of MXene are not as explored and studied as energy-related applications, especially energy storage devices. However, various studies that reported the biomedical-related applications of MXene have revealed the potential of the MXene family in shaping the future of biomedical technologies. After reviewing the literature, this study explored the various biomedical applications of MXene, and its composites reported in several research articles to give a brief insight into the existing synthesis methods and biomedical applications of MXene.

Plant-extracted nanoparticles represent a burgeoning field of nanotechnology, offering a sustainable and eco-friendly approach to nanoparticle synthesis. This study reports the green and eco-friendly synthesis of CuO nanoparticles using the fruits of Peltophorum pterocarpum and their application as nanocatalysts in synthesizing benzothiazole derivatives. The bio-derived CuO nanoparticles were thoroughly characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) techniques. A notable feature of this method is the single-step condensation between 6-substituted-2-aminobenzothiazoles and aromatic aldehydes, which yields novel hetero compounds with an impressive 90-96% yield in less than 2 minutes under microwave irradiation in a solvent-free environment. The synthesized compounds were screened for their antibacterial properties and exhibited significant activity against E. coli, S. aureus, P. aeruginosa, and B. subtilis. In addition, they showed antifungal efficacy against C. albicans and S. cerevisiae. The chemical structures of these compounds were confirmed through infrared spectroscopy (IR), 1H-NMR, Mass, and UV spectral analysis, while their purity was verified using TLC. Notably, the antibacterial activity of these synthesized compounds was found to be superior to that of the original benzothiazole derivatives. The primary advantage of this approach lies in the short reaction time coupled with the excellent yield of prepared.

Ag/PEG/PVA nanocomposites were synthesized using the electrochemical method, in which silver nanoparticles (AgNPs) were incorporated into PEG/PVAmatrices at different time intervals (0, 4, 7, 10, and 13 minutes). Analysis using transmission electron microscopy (TEM) and X-ray diffraction analysis (XRD) absorbance measurements confirmed the bonding of AgNPs to the PEG/PVAmatrix that shows the fact that longer growth times provide more opportunities for silver nanoparticles to aggregate. In addition, the analysis using X-ray diffraction showed that the AgNPs had a structure with face-centered cubic structure. In the last part of this study, synthesized nanocomposites showed strong antibacterial properties against E.coli and Staphylococcus aureus, with a large inhibition zone of 68 mm.

The novel ligand ((E)-2-((4-methoxybenzyl)imino)methyl)-4-methylphenol) and its Cu(II) metal complex were synthesized and extensively studied using NMR, FT-IR, and UV-Visible spectroscopy. The study found d-d transitions (2Eg → 2T2g) in a Cu(II) complex with a tetragonal distortion geometry. The magnetic moments of the copper(II) complex range between 1.78 and 1.92 B.M., indicating the presence of mononuclear Cu(II). Density functional theory validated the molecular structure of the prepared complexes at the B3LYP functional and B3LYP/6-31+G (d, p) levels. Analyzing the charge distribution and molecular orbitals allowed us to predict the quantum chemical properties of these complexes. We investigated the antifungal and antibacterial activity of the ligand and metal complex, and the results indicate that the copper metal complex is more effective than the ligand.

Wastewater containing toxic compounds poses health hazards to living beings. Current researchfocuses on the degradation of malachite green (MG) as a hazardous pollutant dye by using tirescrap-derived activated carbon (AC) to develop nanocomposites with ZnO by hydrothermal method.The morphology, crystal quality, electrochemical active surface area (ECSA), EIS, antibacterialactivity, and optical and photo luminance aspects were studied. The morphology was studiedby SEM. The crystalline and elemental composition study was performed using XRD and FTIR,respectively. UV-visible spectroscopy and photoluminescence were employed for optical studies.The ZnO@C nanocomposite exhibited a nanorod-like shape and hexagonal phase. The role of ACin ZnO@C composite was investigated for the removal of MG under UV illumination. Resultsexhibited that the degradation rate for MG was highly dependent upon dye concentration and pH.Furthermore, an antibacterial study was performed on the nanocomposites. A significant reductionin the band gap (12.6%) was achieved with excellent degradation efficiency of 100%. These resultssuggest that tire scrap waste could produce a new class of carbon materials for various applications,especially in the energy, environment, and biomedical sectors.

2,3-butandionemonoxime and 2-amino-4-nitrophenol were condensed to produce a novel Schiff base ligand (2E,3E)-3-((2-hydroxy-5-nitrophenyl) imion) butan-2-one oxime. In molar ratios of 1:1 and 1:2, Cobalt (II), Nickel (II), Copper (II), Palladium (II), and Platinum (II) complexes have been synthesized by reacting the ligand with metal chloride salts to obtain [Ml. Cl2] and [Ml2.Cl2] complexes. Elemental analysis (C. H. N.), molar conductivity, magnetic susceptibility, and spectral (FT-IR, 13C, 1H-NMR,1H-1H 2D-NMR (NOE), GC-MS, UV-Visible, and stoichiometry analysis Job`s method) studies were used to characterize all synthesized compounds; the ligand exhibits the formation of a new azomethine (C=N) group, and the Ni(II), Pd(II), and Pt(II) complexes screened as a square planer structure, whereas the Co(II) complex showed as a low-spin octahedral and the Cu(II) complex as a distortion octahedral. The antibacterial activity of the starting material, ligand, and complexes has been examined using the good diffusion method against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria. According to the activity data, metal complexes and ligands are more active than the starting material, especially the Co(II) complex. Pt (II) complex exhibits the lowest MICs of all the prepared compounds. In this research, we used SEM and EDX methods to investigate the surface properties of the Co (II) complex, which have been particles of nanosize and shape.

Due to the cell affinity of chitosan (CS), the hydrophilicity of polyethylene oxide (PEO), and the antibacterial activity of plant-derived compounds such as Arctium lappa L. (A. lappa) extract, a CS/PEO/A. lappa nanofiber reinforced with graphene oxide (GO) can be extensively used as wound healing dressings for skin tissue regeneration. Therefore, in this study, CS/PEO nanofibrous scaffolds containing different concentrations of extract and GO were fabricated using the electrospinning method.

The CS/PEO scaffolds with a weight ratio of 1:2, containing different concentrations of A. lappa extract (15, 25, and 35% w/v), were fabricated using the electrospinning method. The optimal concentration of extract was 25% w/v based on the nanofibers' average diameter and its lower standard deviation. Then, 0.5 and 1% w of GO was added to the optimal solution of CS/PEO/A. lappa extract. The scaffolds were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray analysis (EDX), thermogravimetric analysis (TGA), and antibacterial evaluation.

FE-SEM studies revealed that smooth, uniform, and defect-free electrospun nanofiber scaffolds were obtained between the average diameter of 226.61 ±14 and 643 ±152 nm. By addition of GO 1% w to CS/PEO/A. lappa 25% w, gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) were better inhibited than gram-positive bacteria (Staphylococcus aureus). We concluded that incorporation of A. lappa extract and GO into CS/PEO nanofiber scaffold could improve its antibacterial and structural properties, making it suitable for potential biomedical applications.

In this study, some of new linear and cyclic formazans based on trimethoprim were synthesized through the reaction of diazonium salt with imine carbanions, to produce target compounds. All of the synthesized compounds were obtained through the convenient and mild conditions with good to high yields and characterized by 1H NMR, 13C NMR, CHNS and FT-IR techniques. The biological activity of products was evaluated against gram-positive and gram-negative bacteria. Obtained results shown the considerable inhibition against the gram-negative bacteria.

The alkylation of 5-(((4-bromophenyl) (3,4,5-trimethoxybenzyl) amino) methyl)-1,3,4-oxadiazole-2(3H)-thione was successfully achieved through an alkylation reaction in absolute ethanol. Six alkyl halides were utilized in K2CO3 (anhydrous) medium at room temperature. 1H NMR, 13C NMR, FTIR and EIMs are used to characterize the resulting compounds. Antibacterial activity assay was conducted on all compounds against S. aureus and E. coli bacteria which displayed significant antibacterial activities. Molecular docking was employed to prioritize compounds for assessing their potential to bind to the target of interest. Each compound exhibited a significant decrease in binding free energy (ΔG) compared to the co-crystallized ligand (human PPARα agonist). The heterocyclic compounds demonstrated an effect on peroxisome proliferator-activated alpha receptors, which are utilized in the treatment of hyperlipidemia. Consequently, the synthetic compounds containing a thioalkyl group, a para-bromobenzene group, as well as a 3,4,5-trimethoxybenzyl group, exhibited an enhanced activity on PPARα receptors.

At present, the escalating magnitude of waste represents a formidable global concern, wherein paper waste alone constitutes approximately 26% of the overall waste deposited in landfills. Thus, the transformation of paper waste into viable products assumes paramount significance. In this study, paper waste was converted to CaCO3 using a thermal process and surface-modified with stearic acid. The effect of environmental pH and process temperature on the crystalline structure and morphology of the product was evaluated. The prepared CaCO3 was used to deactivate gram-negative agrobacterium tumefaciens and hydrophobicity's effect on the CaCO3 antibacterial activity was studied. XRD, SEM, FT-IR, BET/BJH, contact angle, and TEM characterization techniques were utilized to characterize the structure and physicochemical properties of prepared CaCO3. According to the XRD analysis, the optimal temperature for the conversion process was 500°C in an air environment without any changes in pH. SEM analysis confirmed that as the calcination temperature increased, the number of cracks and holes on the surface also increased. BET analysis confirmed this by showing a decrease in the specific surface area in the Ca-750 sample. TEM analysis revealed nanoparticles with spherical and irregular spherical geometries, ranging in size from 30 to 90 nm. According to the contact angle analysis, increasing the concentration of stearic acid led to an increase in the contact angle to 121.4°. This increase in contact angle indicates an enhancement in the hydrophobicity of the prepared nanoparticles, which had a synergistic effect on their antibacterial activity. The antibacterial activity test of both prepared hydrophilic and hydrophobic CaCO3 depicted the high antibacterial activity of both CaCO3 while the hydrophobic CaCO3 revealed higher antibacterial activity compared to hydrophilic CaCO3.

In this work, novel antibacterial drugs that are tetrazole derivatives connected to the 1-position of the heterocyclic ring (benzimidazole) via a methyl bridge were designed and synthesized. The final chemical structures of the prepared tetrazole derivatives were confirmed by nuclear magnetic resonance (1H NMR and 13C NMR), and Fourier-transform infrared spectroscopy (FTIR) spectroscopy. Three types of Candida were used to investigate the synthetic compounds' antifungal properties: Candida albicans, Candida glabrata, and Candida parapsilosis. Compounds e1 and b1 have greater efficacy against Candida albicans than normal fluconazole, while compound d1 shows greater efficacy against Candida glabrata. The ability of compounds to combat gram-positive and gram-negative, Klebsiella pneumoniae, Staphylococcus aureus, Escherichia coli, and Enterococcus faecalis was also assessed. The lowest inhibitory concentrations of compounds e1, b1, and c1 against E. faecalis were comparable to those of the control drug azithromycin. Modeling studies were conducted against the 14-α demethylase enzyme found in Candida species. When it came to combating Candida species, e1 was the most effective chemical and had the highest docking contact energy. Based on the theoretical ADME of prepared compounds calculated, the molecule profiles meet the limitation rule requirements.

Bioactive natural compounds are found in medicinal plants through secondary metabolites, which are commonly referred to as bioactive natural compounds. The use of antioxidants and antimicrobials has become increasingly popular in recent years. Our objective is to assess the antibacterial and antioxidant effects of Salvia officinalis extracts from the Nechmaya region (Wilaya Guelma - ALGERIA) in this study. This study aims to understand the organoleptic characteristics of essential oils and to obtain different yields depending on the harvest periods, as well as the polyphenol and flavonoid content of the plant. The antiradical activity results from the DPPH method indicate that the methanolic extract has a stronger antioxidant activity than the essential oil.