Antibacterial Evaluation Research Articles

Synthesis, Characterization, Thermal aspects, Density Functional Theory study and in-vitro antibacterial evaluation of Cr(III) complexes based on Pyrazolone Phenylhydrazone Ligands

Synthesis, Characterization, Thermal aspects, Density Functional Theory study and in-vitro antibacterial evaluation of Cr(III) complexes based on Pyrazolone Phenylhydrazone Ligands

A Synthetic Route Towards Spiro Indanone Fused Pyrano[2,3‐c]Chromene Derivatives via Oxa–Diels–Alder Reaction: Computational Investigation, Antibacterial Evaluation and Molecular Docking Studies as Potential DNA Gyrase Inhibitors

ABSTRACTA highly efficient method for the synthesis of 2′H‐spiro[indene‐2,3′‐pyrano[2,3‐c]chromene] derivatives 20(a–s) has been developed involving oxa–Diels–Alder reaction as the key step under conventional conditions in good to excellent yields. The compounds were all characterized using 1H, 13C NMR, HRMS, and X‐ray crystallography. The present study employs DFT to validate the reaction pathway. In vitro antibacterial assay of all the synthesized derivatives was evaluated against Gram‐negative Escherichia coli and Gram‐positive Staphylococcus aureus bacterial strains. Compound 20e was found to be the most potent molecule with ZI of 19 mm and MIC of 16 μg mL−1 in E. coli and ZI of 14 mm and MIC of 32 μg mL−1 in S. aureus. Additionally, 20e demonstrated a strong inhibition of DNA gyrase in silico, with a binding affinity of −9.3 and − 9.0 kcal/mol in E. coli and S. aureus respectively. Also, significant pharmacokinetic, physicochemical, and drug‐like properties of the spirocyclic compounds were further corroborated by ADME investigations. Hence, these new series of spiro indanone fused pyrano[2,3‐c]chromene derivatives may be potent druggable antibacterial agents in future.

LC-MS guided discovery of a new type of abyssomicin, glycoabyssomicin A, from a deep-sea derived Streptomyces

Glycoabyssomicin A (1), a new type of abyssomicin containing a sugar unit, was isolated from the deep-sea derived Streptomyces koyangensis SCSIO 5802 guided by LC-MS. The structure of 1 was elucidated by HR-ESI-MS, 1D-NMR (1H,13C NMR), 2D-NMR (HSQC, COSY, HMBC, NOESY), and TFA hydrolysis and acetylation reactions. In the antibacterial activities evaluation against a series of gram-positive and gram-negative bacteria, it showed inactive at the concentration of 10 μg per filter paper disc. This finding would broaden the way for discovery of more lead compounds of abyssomicins.

Synthesis, in vitro antibacterial and antioxidant evaluation, DFT calculation, molecular docking, and ADMET studies of novel N-Acyl-6-chloro-2(3H)-benzoxazolone derivatives

A new series of N-acyl-6-Chloro-2(3H)-benzoxazolone derivatives (4a-4g) were synthesized using an eco-friendly catalyst. The compounds were characterized using spectroscopic techniques, including FTIR, 1H NMR, 13C NMR, and GC–MS. Their antimicrobial activity against various bacterial strains, including both Gram-negative and Gram-positive bacteria, was evaluated and yielded promising results. The synthesized compounds were also tested for their antioxidant properties using the DPPH radical-scavenging method, where compound 4f exhibited the highest activity with an IC50 of 1.54 μg/mL, surpassing that of ascorbic acid (IC50 = 1.7 μg/mL). Additionally, DFT calculations were performed to investigate the compounds’ chemical reactivity, including the analysis of HOMO and LUMO frontier molecular orbitals, global reactivity descriptors, and molecular electrostatic potential. Molecular docking studies were conducted to explore the interactions between the synthesized compounds (4a-4g) and the standard drug ciprofloxacin at the active site of DNA gyrase. Furthermore, physicochemical properties, lipophilicity, water solubility, pharmacokinetics, drug-likeness, and medicinal chemistry properties were estimated using SwissADME. Toxicological profiles, including hepatotoxicity, carcinogenicity, immunotoxicity, mutagenicity, cytotoxicity, and LD50, were predicted using the ProTox-III web tool. The findings suggest potential therapeutic applications for combating bacterial strains, indicating that these synthesized compounds could serve as lead compounds for antibiotic drug development.

Green synthesis, characterization and antibacterial evaluation of ZnO and Ag-doped ZnO nanoparticles using Ruta chalepensis leaf extract

ABSTRACT In this study, a facile, green, and eco-friendly approach was followed for the synthesis of zinc oxide (ZnO), Ag-doped ZnO nanoparticles (NPs) using Ruta chalepensis leaf extract. The biosynthesized nanoparticles were characterized by X-ray diffraction (X-RD), Fourier transform infrared spectroscopy (FT-IR), energy dispersive X-ray (EDX), and ultraviolet–visible spectroscopy (UV-Vis). The UV-Vis absorbance peaks for ZnO, 5%, and 7% Ag-doped ZnO NPs were 357, 360, and 364 nm, with band gaps of 3.00, 2.73, and 2.83 eV, respectively. The XRD data showed average crystalline sizes of ZnO, 5% Ag-doped ZnO, and 7% Ag-doped ZnO NPs were 13.82, 27.50, and 25.92 nm, respectively. The presence of a functional group was confirmed by FTIR spectrum. The improved antibacterial activity of Ag-doped ZnO NPs was due to Reactive Oxygen Species (ROS) formation. The higher zone of inhibition was observed in S. aureus and B. cereus (11 ± 1.0 and 12.33 ± 0.57 mm, respectively), by 7% Ag-doped ZnO NPs. Our finding showed that synthesized Ag-doped ZnO NPs possessed good antibacterial activity as compared to pure ZnO NPs. Hence, the designed plant leaf mediated Ag-doped ZnO NPs synthesis has provided avenues for the enhancement of the high efficiency of its antibacterial activity, this makes the study unique.

Exploration of pyridine-thiazolidin-4-one: Synthesis, DFT study, UV–Vis/ fluorescence spectroscopy analysis, antibacterial evaluation and molecular docking

The synthesis of the objective pyridine-thiazolidin-4-one (DCPI-MBT) was involved via the Knoevenagel reaction between 2-((3,5-dichloropyridinyl)imino)thiazolidinone derivative 1 and 4-methylbenzaldehyde 2 over refluxing in acetic acid and sodium acetate. The confirmed structure of this hybrid was elucidated through detailed spectral analyses. A comparison was made between the density functional theory (DFT) configurations of the frontier molecular orbitals in both the gas and solvated ground state (So) and the solvated excited state (S1). UV–Visible and fluorescence spectra of the thiazolidin-4-one derivative were obtained in DMSO, displaying a significant Stokes’ shift (Δν¯= 3136.81 cm−1). The synthesized DCPI-MBT was established to see how well they killed different kinds of pathogenic microbes, such as bacteria, viruses, and fungi. These results demonstrate that the synthesized DCPI-MBT has a broad-spectrum antibacterial capability that is on par with or even superior to conventional treatments in certain instances. Moreover, molecular docking simulation was used to evaluate the bindings of the synthesized DCPI-MBT with a target protein (PDB: 1kzn). The binding energies, RMSD values, kinds of interactions with amino acid residues, and interaction distances of the hybrids were determined based on their substituent changes. This study analyzed the pharmacokinetic profiles of newly DCPI-MBT, using SwissADME predictions to focus on their potential as therapeutic agents. The DCPI-MBT has the promising pharmacokinetic profile for future development as a therapeutic drug, with optimum solubility, bioavailability, and a favorable interaction profile with biological targets.

Synthesis and Antibacterial Evaluation of Novel Small-Molecule Antibacterials of a Reduced Acridine Structure in S. aureus Strains Including MRSA.

The increasing antibacterial drug resistance remains a threat to global health with increasing mortality and morbidity. There is an urgent need to find novel antibacterials and develop alternative strategies to combat the increasing antibacterial drug resistance. <P> </P> Objective: We aimed to synthesize novel small-molecule antibacterials to evaluate the structuredependent antibacterial compound activities against S. aureus and MRSA. <P> </P> Method: Compounds were synthesized by primary N-alkylation to form alkyl acridinium salts that were further functionalized with substituted phenyl residues and finally purified by column chromatography. The antibacterial growth inhibition activity was determined as MIC value. <P> </P> Results: The substituent effects on the determined antibacterial growth inhibitory properties have been discussed. <P> </P> Conclusion: The best activities have been found for compounds with methoxy functions, exceeding the activities of reported novel antibacterial peptides. The compounds have also shown antibacterial drug-enhancing effects, which have been manifested as a reduction in the MIC values of the used antibiotics.

Rational design, synthesis, computational studies and biological evaluation of new diazepanone derivatives: Crystal structure of 2,7-bis(4-chlorophenyl)-1,3-dimethyl-1,4-diazepan-5-one

Structural and biological evaluation of newly designed and synthesized diazepanone derivatives (3a-c) with modified functionalities is reported in this paper, as liponucleoside class of antibiotics possessing 1,4-diazepanone as core moiety are under investigation since last decade to improvise their drug action. FT-IR, HR-ESI-MS, 1H NMR and 13C NMR spectral studies are used for the structural characterization of synthesized compounds (3a-c). 1H NMR spectral data reveal that the diazepanone ring exhibits chair conformation in solution state. The solid state geometry for compound 3a acquired by SC-XRD study also in favour of chair conformation of the diazepanone ring with equatorial orientation of all the substituents. Comparison of experimental bond parameters with theoretical results attained by DFT studies using B3LYP/6–311G++ (d,p) basis set are in good agreement. Molecular electrostatic potential surface (MEPS) and HOMO-LUMO energies are used to elucidate the topology and physicochemical parameters of 3a. Nature of crystal packing is ascertained by Hirshfeld surface and its delineated 2D-Fingerprint plot in addition with the SC-XRD evidences. Antibacterial evaluation of (3a-c) against tested bacterial strains reveals that the compounds have remarkable antibacterial potencies compared to tested standard drug. Among the compounds 3a-c, the compound 3c with fluoro-substitution on the phenyl ring shows highest activity.

Exploring the Potential of New 7‐Chloroquinoline‐benzylamine Hybrids as Antimicrobials: Synthesis, Biological Activity and MD Simulation Studies

AbstractNovel drug like chloroquinoline‐benzylamine hybrids were synthesized and subjected to comprehensive antibacterial evaluation in the present investigation. The pharmacological evaluation comprises determination of minimum inhibitory concentration (MIC), disk diffusion assay, hemolysis and combination assays against both Gram‐negative (Pseudomonas aeruginosa) and Gram‐positive (Bacillus subtilis, Enterococcus faecalis, and Staphylococcus aureus) bacterial strains. Among all, 7‐chloroquinoline‐benzylamine hybrid bearing p‐bromophenyl substituent (SA11) demonstrated significant antibacterial efficacy (MIC=128μg/mL) against the tested panel of Gram‐positive strains with no sign of toxicity towards human red blood cells (hRBCs). Furthermore, another hybrid with o‐hydroxyphenyl substitution (SA12) exhibited notable activity against the tested isolates with MIC values ranging from 64 to 256μg/mL. Molecular docking studies suggested compound SA11 binds within the active site of the biofilm causing protein (PDB: 7C7U) further supported by the molecular dynamics (MD) simulation studies at 100 ns. Compound SA11 exhibited significant efficacy in inhibiting S. aureus growth in the disk diffusion assay. Moreover, it displayed a synergistic effect when combined with ciprofloxacin (CIP), implying its potential utility in addressing antibiotic‐resistant bacterial strains through combination therapy. The pkCSM‐Pharmacokinetics assessment indicated favourable ADME profiles for SA11, supporting its potential as a viable drug candidate.

Synthesis, Characterization and Antibacterial Activity Evaluation of CuO NPs and B-CuO NPs obtained from Livistona chinensis leaf extract.

Nanoparticles (NPs) exhibit fascinating size-dependent chemical and physical characteristics that make them useful for a variety of applications. The present paper reports the green synthesis of CuO NPs and B-doped CuO NPs (B-CuO NPs) from Livistona chinensis leaf extract. Not much work has been reported on the use of the plant extract for the fabrication of NPs, particularly those of Cu and its doped counterparts. Various spectroscopic techniques were used to characterize the synthesized NPs. In the FT-IR spectra, peaks obtained at 504 cm-1 to 600 cm-1 were due to Cu-O vibrations. The energy dispersive X-ray analysis (EDX) spectra confirmed the CuO NPs' composition and B's presence inside the NPs. The peak pattern in X-ray diffraction (XRD) spectrum confirmed the crystalline and monoclinic phases of the NPs. The average crystalline size of CuO NPs and B-CuO NPs was 19.56 nm and 17.30 nm respectively. The CuO and B-CuO NPs were tested against three Gram-positive bacterial strains namely Bacillus subtilis, Micrococcus luteus, and Staphylococcus aureus and three Gram-negative Escherichia coli, Salmonella abony, and Pseudomonas aeruginosa through Agar well diffusion method and it was found that CuO NPs showed higher activity than B-CuO NPs.

Cryptophytes as potential source of natural antimicrobials for food preservation.

Cryptophytes are a promising source of bioactive compounds that have not been fully explored. This research investigated the antimicrobial activity of total phenolic compounds (TPC) and exopolysaccharides (EPS) extracted from several cryptophytes against a range of harmful foodborne bacteria and fungi. To measure the minimum inhibitory concentration (MIC) value, the broth microdilution method was used. In the antibacterial evaluation of TPC, the MIC ranged between 31.25 and 500 μg/mL, while for the antifungal activity test, it varied from 31.25 to 125 μg/mL. In the antibacterial activity test of EPS, the MIC values ranged from 125 to 1,000 μg/mL, whereas in the antifungal susceptibility test, it ranged between 62.5 and 1,000 μg/mL. The most resistant pathogen against TPC was Escherichia coli, while Campylobacter jejuni was the most susceptible. In the case of EPS, the most resistant pathogen was Salmonella Typhimurium, while Aspergillus versicolor exhibited the highest susceptibility. Overall, in terms of antimicrobial activity, TPC was more effective than EPS. Finally, the tolerance level (TL) for TPC and EPS was ≤4 in all tested samples, indicating their bactericidal/fungicidal mechanism of action. In conclusion, TPC and EPS isolated from cryptophytes demonstrated remarkable antimicrobial properties and ability to fully eradicate pathogens, and could be considered as natural preservatives in the food industry.

Chemical Profile, Antioxidant and Antimicrobial Activity of Marine Sponge Species Combined with Multivariate Statistical Analyses: Desmapsamma anchorata, Dysidea etheria and Echinodictyum dendroides.

Marine sponges are sources of bioactive compounds, sparking pharmacological interest. This study aimed to evaluate the chemical profile, antioxidant, and antibacterial activities of the species Desmapsamma anchorata, Dysidea etheria, and Echinodictyum dendroides. The chemical profile was characterized by the identification and quantification of polyphenols. Antioxidant activity was assessed using different methods. Antibacterial and modulatory activities were evaluated through microdilution against pathogenic strains. The polyphenols were found in low abundance in the extracts. In the antioxidant assays, the EACDa and EMDa extracts exhibited better inhibitory results. In the antibacterial evaluation, extracts presented MIC ≥ 1024 µg mL-1. The modulation of the extracts in combination with antibiotics showed significant effects against the multiresistant bacterium Pseudomonas aeruginosa. This study contributes to the deepening of chemical and biological knowledge of sponge species, indicating that their extracts can act as good modulators of bacterial resistance to aminoglycoside antibiotics, warranting further investigation into their mechanisms of action.

Response surface optimization for supercritical carbon dioxide extraction of Korarima (Aframomum corrorima) seed oil and its antibacterial activity evaluation

Oils extracted from natural plants are valuable resources because of their diverse biocidal activity against microorganisms. This paper reports, for the first time, supercritical CO2 extraction of oil from Korarima (Aframomum corrorima) seeds and its antibacterial activity evaluation. The influences of pressure, temperature, and extraction time on the yield of supercritical CO2-extracted oil (scCO2-extracted oil) were optimized using the Response Surface Methodology. Under the optimal extraction conditions of 46 °C, 15.5 MPa, and 147 min, the extraction yield reached 1.60±0.04 %, consistent with the theoretical value of 1.58 %. The compositions of the scCO2-extracted oil were identified by GC-MS, primarily consisting of nerolidol (33.97–41.20 %), geraniol (23.08–24.50 %), and α-terpinene (8.90–9.06 %). The oil exhibited significant antibacterial activity against Staphylococcus. aureus with a minimum inhibitory concentration of 1 mg·mL−1. This study highlights the potential applications of supercritical CO2 extraction technology for extracting Korarima seed oil and its use as an antibacterial ingredient in cosmetics and pharmaceuticals.

4+2] Cycloaddition Mediated Stereoselective Synthesis of Tetrahydro‐1H‐Isobenzofuro Chromene Dione Derivatives: Antibacterial Evaluation and Molecular Docking Investigation

AbstractAn efficient stereoselective synthesis of tetrahydro‐1H‐isobenzofuro[4,5‐c]chromene‐1,3(3aH)‐dione derivatives were achieved through a novel [4+2] cycloaddition reaction of 4‐styryl‐2H‐chromenes with cheaply available maleic anhydride. A series of new tetrahydro‐1H‐isobenzofuro[4,5‐c]chromene‐1,3(3aH)‐dione derivatives 21(a–p) were synthesized in good to excellent yield under mild reaction condition with no chromatographic purification. In this reaction, the generation of four new consecutive stereogenic centers were determined by single crystal X‐ray analysis. All the synthesized compounds were investigated further in silico and in vitro for antibacterial activities using two bacterial strain of DNA gyrase. Compounds 21 b and 21 j showed excellent docking score −9.3 kCal/mol and −8.6 kCal/mol with gram negative bacterial strain Escherichia coli (E. coli) with protein data bank (PDB ID) 3G7E. Out of all the tested molecules, 21 b and 21 j displayed good results with minimum inhibitory concentration 10 μg/ml, 10 μg/ml against the bacterial strain Escherichia coli(E. coli) and 10 μg/ml, 20 μg/ml against Staphylococcus aureus (S. aureus) respectively.

SUPERIOR ANTIBACTERIAL PROPERTIES OF COPPER-BEARING HIGH ENTROPY ALLOY COATED STAINLESS STEEL SURFACE FABRICATED USING LASER CLADDING

A high-entropy alloy (HEA) coating is applied to a stainless-steel surface using the laser cladding (LC) process. This coating offers a broad-spectrum antibacterial ability and favorable mechanical properties. The release of copper ions from the HEA effectively inhibits the growth of Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus), enhancing the alloy’s suitability for various applications requiring antibacterial properties. The elemental compositions, sizes, and morphologies of the constructed HEAs are revealed through X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDX). This study validates the feasibility of applying the antibacterial CoCrFeCuNi HEA alloy coating to stainless steel via LC. The antibacterial evaluation showcases the enhanced efficacy of the CoCrCuFeNi HEA coating, demonstrating an antibacterial effectiveness of approximately 89% against E. coli and 98% against S. aureus. In contrast, the CoCrFeNi HEA coating exhibits an antibacterial effectiveness of about 40% against E. coli and 93% against S. aureus. The Vickers hardness of the stainless steel coated with CoCrCuFeNi HEA has significantly increased to 352 HV, compared to the CoCrFeNi coating with a hardness of 300.6 HV and the uncoated stainless steel with a hardness of 256.6 HV. This HEA alloy demonstrates considerable potential for use in medical applications or other settings that require antibacterial features.

In vitro and In silico Antibacterial Evaluation of N-Methyl-2-phenylmaleimides

Background: Novel antibiotics are needed to stem the rise of antimicrobial resistance. N-Methyl-2-phenylmaleimide (NMP) compounds previously synthesised by our research group are structural analogues of 2,3,5-substituted perhydropyrrolo[3,4-d]isoxazole-4,6-diones found by others to have antibacterial activity. Objectives: This study aims to explain the significance of NMPs and their antibacterial activity. The antibacterial activity of the NMPs was determined against Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa. The partition coefficient of the NMPs and a pharmacophore model were used to explain their antibacterial activity. Methods: The Kirby Bauer Disc diffusion method was used to screen the NMPs for activity, while the broth microdilution method was used to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the active NMPs. Using the in vitro antibacterial activity of 2,3,5-substituted perhydropyrrolo[3,4-d]isoxazole-4,6-diones, a common feature pharmacophore model was constructed and validated. The rank score, fit value, enrichment factor (EF20%), and receiver operating characteristic area under the curve (ROC-AUC) were used as validation metrics. Results: The NMPs were only active against S. aureus, with compound 3 (4 µg/ml) being the most active. The majority of NMPs were bacteriostatic. A common feature pharmacophore model was validated (rank score: 120.5; fit value: 4; EF20%: 4.3; ROC-AUC: 0.9 ± 0.03) and showed that three hydrogen bond acceptors and a ring aromatic region are important for activity. Comparing the partition coefficient of the NMPs to their MIC a statistically significant correlation was found. Conclusion: NMPs can be used as lead compounds in future studies. The validated pharmacophore model and partition coefficient can be used to develop more active compounds.

Silver Nanoparticles Loaded with Bark Extract of Sterculia foetida: Their Green Synthesis, Characterization, and Anti-bacterial Activity Evaluation

Sterculia foetida is a subject of interest in many scientific fields as researchers look for novel treatments because of its varied medicinal qualities and chemical richness. Terpenoids are aromatic and aliphatic chemicals with anti-bacterial properties and can prevent free radical damage. They are present in S. foetida extract. Moreover, it possesses immunomodulatory, hepatoprotective, antiviral, antioxidant, anti-inflammatory, and antifungal properties. This work aims to green synthesize, characterize, and evaluate the anti-bacterial activity of Sterculia foetida bark extract-loaded silver nanoparticles. Chemicals like Methanol, Petroleum Ether, and water have been used to extract the phytoconstituents from the plant bark. AgNO3 and Silver have been used to synthesize the nanoparticles. Instruments like ATR-IR Spectrophotometer, UV- spectrophotometer, DLS, and SEM instruments have been used to characterize the nanoparticles. Bacterial strains like Staphylococcus aureus (ATCC-6538), Escherichia coli (ATCC 25922), saline water, AMX30, swab stick, inoculation loop, susceptibility scale have been used for studying the anti-bacterial activity. DLS and zeta potential analysis demonstrated the creation of stable nanoparticles with a particle size of 79 nm. The anti-bacterial activity of AgNPs with the methanolic bark extract showed significant anti-bacterial activity compared to the standard marketed drug AMX30. The highest zone of inhibition was observed against gram-positive bacteria S.aureus (1.68 cm) and gram-negative bacteria E.coli (1.74 cm), respectively, at 500 μg/ml concentration. The study concludes that greenly synthesized S. foetida bark extract containing nanoparticles is a potential anti-bacterial agent, especially against gram-negative bacteria. Further, in vivo studies are needed to establish its potential. Keywords: Sterculia foetida, Green synthesis, Silver Nanoparticles (AgNPs), ATR-IR, DLS, SEM, Zeta-potential, Anti-bacterial.

Design, Synthesis, Antibacterial, and Antifungal Evaluation of a New Series of Quinazoline-Thiazole and /or Quinazoline-Triazole Hybrids as Bioactive Heterocycles.

Herein, a one-pot reaction between cyclohexanone, thiourea, and 2,5-dimethoxybenzaldehyde allowed to prepare hexahydroquinazoline-2(1H)-thione 4 firstly, which dollowed by reacting with hydrazine hydrate to produce the corresponding 2-hydrazinylhexahydroquinazoline 6. Interesting analogs of thiazolo[3,2-a]quinazoline 7-13 where obtained when hexahydroquinazoline-2(1H)-thione 4 reacted with 1,2-dibromoethane, chloroacetyl chloride, bromoacetic acid, bromoacetic acid/4-chlorobenzaldehyde, 2-bromopropionic acid, ethyl bromocyanoacetate, and/or bromomalononitrile; respectively. While triazolo[4,3-a] quinazoline 14-16 were created when 2-hydrazinylhexahydroquinazoline 6 reacted with triethyl orthoformate, acetic anhydride, and carbon disulfide respectively. Additionally, the new analogs were examined for their antibacterial and antifungal properties against Escherichia coli, Staphylococcus aureus, and Candida albicans. It was discovered that triazolo[4,3-a] quinazoline analogs 14-16 have superior bacterial and fungal activity when compared to the corresponding conventional doses of Streptomycin and Griseofulvin. Towards Candida albicans; compounds 14, 15, and 16 increase activity with 1.14%, 1.15%, and 1.21%, respectively more than griseofulvin.While, for Staphylococcus aureus; compounds 14, 15, and 16 increase activity with 1.5%, 1.5%, and 1.7%, respectively more than streptomycin. Morever, for Escherichia coli; compounds 14, 15, and 16 increase activity with 1.19%, 1.21%, and 1.22%, respectively more than streptomycin. Finally, structure activity relationships show that quinazoline derivatives exhibit higher activity when fused to pyrazole ring 14-16 as compared when fused thiophene ring 7-13.

Synthesis and antibacterial evaluation of (5Z)-5-[(2-piperidinequinoline-3-yl)methyl]-2-chloroquinoline derivatives: Docking study on substituted N-alkylation and binding mechanisms with E. Coli PDF enzyme

A number of new substances were included into the (5Z)-5-[(2-piperidinequinoline-3-yl)methyl]-2-chloroquinoline structural framework. The condensation process 2-chloroquinoline, which served as a crucial reagent in the reaction with 3-carbaldehydes to produce 2,4-thiazolidinedione, allowed for the production of 1,3-thiazolidine-2,4-dione. The newly developed substances were described by means of their reactions with halide compounds, particularly those pertaining to substituted N-alkylation. Elemental analysis, Fourier-transform infrared spectroscopy (FT-IR), and proton nuclear magnetic resonance spectroscopy (1H NMR) were used to identify the chemical. Furthermore, the antibacterial activity of the produced compounds was evaluated in vitro against a range of pathogens, including Bacillus subtilis, and Escherichia coli. Moreover, docking experiments were conducted using the PDF enzyme of E. coli to improve our understanding of the binding mechanism between the synthesized 5(A-N) compounds and the enzyme.

Antibacterial evaluation of garlic extracts on chitosan/starch packaging film using response surface methodology and its application for shelf-life extension of bell peppers (Capsicum annuum).

In this study, garlic extract (GE) was assessed as a potential additive in chitosan/starch (Ch/De) coatings, focusing on phenolic and flavonoid content analyses and antibacterial properties. Using response surface methodology approach, an optimization method was employed to achieve the optimal antibacterial formulation, with Ch, De, and GE identified as key variables in the Design of Experiment. Fourier transform infrared spectroscopy and X-ray diffraction analyses elucidated interactions among these primary components within the films, while thermogravimetric analysis confirmed the enhanced thermal stability of GE-coated film formulations (Ch/De/GE). The Ch/De/GE exhibited antibacterial efficacy against Escherichia coli (ATCC 25922) with an inhibition zone of 7.2mm at optimized concentrations of 2% w/v Ch, 1.5% w/v starch, and 0.5% v/v GE. In silico molecular docking studies provided insights into GE's inhibitory role as an antibacterial agent. Evaluation of green and yellow bell peppers (Capsicum annuum) over 18 days showed that coated peppers maintained better visual appearance and mass stability, with a weight loss decrease of 40.54%-48.96%, compared to uncoated ones. Additionally, the Ch/De/GE coating effectively inhibited bacterial growth, reducing it by 1-1.23 log CFU, during the storage period. In conclusion, the Ch/De/GE coating effectively extends the shelf-life of bell peppers and maintains their quality, demonstrating its potential for use in food packaging to preserve perishable items. PRACTICAL APPLICATION: The optimized chitosan/starch/garlic extract (Ch/De/GE) film developed in this study shows promising potential for application in the food packaging industry, particularly in extending the shelf life of perishable items like bell peppers. Its enhanced antibacterial properties, along with its ability to maintain visual appearance and reduce weight loss, make it an effective natural preservative that could replace synthetic additives in food packaging. By incorporating this biodegradable film into packaging solutions, producers can offer safer, more sustainable products that meet consumer demand for natural and environmentally friendly options.