Potential Antimicrobial Agents Research Articles

Cinnamaldehyde in Focus: Antimicrobial Properties, Biosynthetic Pathway, and Industrial Applications

Trans-cinnamaldehyde (TCA), a major bioactive compound derived from cinnamon (Cinnamomum spp.), has garnered significant attention for its diverse therapeutic properties. Its broad-spectrum antimicrobial activity, targeting both Gram-positive and Gram-negative bacteria as well as various fungi, positions TCA as a potent natural antimicrobial agent. Beyond its antimicrobial effects, TCA demonstrates promising antidiabetic and anti-inflammatory activities, making it a valuable compound in medicinal and cosmetic applications. Recent studies have highlighted its role in disrupting microbial membranes, inhibiting biofilm formation, and modulating key metabolic pathways in pathogens. Furthermore, TCA has gained popularity in cosmetics due to its antimicrobial activity, antioxidant properties, and skin-friendly profile. This review provides a comprehensive overview of TCA’s antimicrobial potential, focusing on its mechanisms of action and its market and industrial applications. We also discuss the biosynthetic pathway of TCA, exploring both its natural production in cinnamon and advances in biotechnological production methods. As the demand for sustainable and natural antimicrobial agents grows, TCA emerges as a promising candidate for diverse applications. Finally, this review explores future directions for optimizing TCA production through metabolic engineering and synthetic biology approaches to meet industrial-scale demands.

Exploring the Antibacterial Properties and Chemical Profiles of Essential Oils from Syzygium aromaticum and Nigella sativa Against MDR Bacteria

For centuries, plants have been studied for their healing properties. Recently, the rise of antibiotic resistance in bacteria has prompted scientists to explore herbal remedies. Syzygium aromaticum, from the Myrtaceae family, has been utilized as a histological clearing agent. In contrast, Nigella sativa (black cumin), a member of the Ranunculaceae family, has long been utilized in traditional medicine dating back to ancient times. The current study investigates the chemical composition and antibacterial activity of essential oils from Syzygium aromaticum (clove) and Nigella sativa (black cumin) against multidrug-resistant (MDR) bacteria. Using the agar well diffusion method, Syzygium aromaticum exhibited significant antibacterial activity, particularly against Salmonella typhi (30.66 mm inhibition zone), while Nigella sativa was effective only against Staphylococcus aureus (19 mm). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values for Syzygium aromaticum ranged from 3.53 to 7.06 mg/mL, indicating stronger antibacterial properties than Nigella sativa (MIC: 12.7 mg/mL, MBC: 22.5 mg/mL). GC-MS analysis revealed that Syzygium aromaticum contained bioactive compounds like Diglycolic acid (76.59%) and Eugenol (2.06%), while Nigella sativa was dominated by Heptasiloxane (80.83%) and Thymoquinone (2.66%). These findings suggest that Syzygium aromaticum essential oil could serve as a potent natural antimicrobial agent against MDR pathogens.

Synthesis and evaluation of vanillin Schiff bases as potential antimicrobial agents against ESBL-producing bacteria: towards novel interventions in antimicrobial stewardship.

The escalating challenge of antimicrobial resistance necessitates the development of novel antibacterial agents. In this study, a series of five vanillin Schiff bases (SB-1 to SB-5) were synthesized from vanillin and various aromatic amines. The chemical structures of these compounds were characterized using Thin Layer Chromatography (TLC), Fourier Transform Infrared Spectroscopy (FT-IR), proton nuclear magnetic resonance ( -NMR), carbon-13 NMR ( -NMR), and mass spectrometry techniques. Antibacterial efficacy was evaluated against strains of bacteria producing extended-spectrum beta-lactamases (ESBL), including Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae using the disc diffusion method. Cytotoxic effects were assessed through haemocompatibility and brine shrimp lethality assays. The Schiff bases demonstrated notable antibacterial activities, with SB-1, SB-2, SB-4, and SB-5 exhibiting zones of inhibition up to 16.0, 16.5, 16.6, and 15.5 mm against ESBL E. coli, respectively. SB-3 showed a maximum inhibition zone of 15.0 mm against ESBL K. pneumoniae. In cytotoxicity assays, the compounds exhibited IC values against red blood cells (RBCs) greater than 200 μg/mL and ranging from 45.7 to 50.5 μg/mL for the brine shrimp assay. While demonstrating potent antibacterial properties, the toxicity towards human RBCs suggests that further toxicity evaluations and structural modifications are essential for developing safer therapeutic agents based on vanillin Schiff bases.

The in vitro Study of the Synergistic Antibacterial Effect of Hydroalcoholic Mentha Extract with Alum on the Growth of Streptococcus mutans

: Antimicrobial resistance poses a significant global health challenge, necessitating the search for novel therapeutic approaches. Streptococcus mutans, a key etiological agent in dental caries, requires innovative strategies due to its biofilm-forming ability and resistance to conventional antibiotics. Natural plant-derived compounds have garnered attention as potential antimicrobial agents with a low risk of resistance development. In this study, we investigated the synergistic antibacterial effect of a hydroalcoholic Mentha extract combined with alum against Streptococcus mutans (PTCC 16836). The well diffusion assay demonstrated that alum exhibited a larger inhibition zone diameter (12.04 ± 2.02 mm) compared to the hydroalcoholic Mentha extract (10.33 ± 1.53 mm). However, the minimum inhibitory concentration (MIC) values for the hydroalcoholic Mentha extract (8.20 ± 5.57 mg/mL) and alum (0.35 ± 0.20 mg/mL) were comparable. The minimum bactericidal concentration (MBC) for the hydroalcoholic Mentha extract was 10 mg/mL, while the MBC for alum was 0.625 ± 0.006 mg/mL. The combination of these substances demonstrated a synergistic effect, indicating enhanced antibacterial activity against Streptococcus mutans. The study's findings suggest potential applications in dentistry, offering a natural and effective adjunctive treatment for dental caries management. The underlying mechanisms of this synergistic effect warrant further exploration. To translate these promising findings into clinical applications, further in vivo investigations and rigorously designed clinical trials are necessary to establish the safety and efficacy of this combination therapy. The natural origin of these substances may provide an environmentally sustainable and cost-effective approach in the fight against antimicrobial resistance.

MUNTINGIA CALABURA SILVER NANOPARTICLES DETERIORATE OXIDATIVE IMPAIRMENT WITH POTENT ANTIBACTERIAL ACTIVITY

Objective: The current study exemplifies the synthesis of silver nanoparticles using Muntingia calabura L. (Mc-AgNP’s) fruit extract utilizing a green approach and testing the efficacy of synthesized NP’s. Methods: The green synthesize approach was used to synthesis Mc-AgNP’s followed by characterization using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Energy Dispersive X-ray Spectroscopy (EDX), and Field Emission Scanning Electron Microscopy (FESEM). Radical scavenging activity was assessed using DPPH, FRAP, and H202, followed by antibacterial activity. Results: The characteristic features of synthesized Muntingia calabura silver nanoparticles (Mc-AgNP’s) were analyzed using FT-IR which particularizes different functional groups with a broadband at 3408 cm-1 representing hydroxyl (-OH) stretching a peak at 1593.27 cm-1 corresponds to C = O groups in amide whereas a dip at 1383 cm-1 represents C-N amine and C-O stretching of alcohol groups were found. The Crystallinity of synthesized Mc-AgNP’s exhibited face-centered cubic (fcc) crystalline structure and the bio-reduction of the silver ions in solution was monitored by Energy dispersive X-ray spectroscopy (EDX). The FESEM analysis indicates that Mc-AgNP’s were dispersed in the solution using micrographs and the size ranged from 10 to 60 nm. The synthesized Mc-AgNP’s efficiently scavenged free radicals in a dose-dependent manner with 69% for DPPH, 59.9% for FRAP, and 64% for H202 respectively. Further, the synthesized Mc-AgNP’s demonstrated a potent antimicrobial agent against tested bacterial and fungal strains with a maximum zone of inhibition observed in S. aureus, K. pneumonia, and P. vulgaris with 14.6, 13.8, and 12.4 mm. Similarly, antifungal activity with Trichoderma harzianum demonstrated the highest zone with 18 mm followed by Aspergillus oryzae with 7 mm. Conclusion: These results highlight the interesting potential of synthesized Mc-AgNP’s as an effective source of bioactive compounds with potent antioxidant and antibacterial activity.

Eco-conscious synthesis of novel 1,2,4-triazolo[1,5-a]pyrimidine derivatives as potent Anti-microbial agent and comparative study of cell viability and cytotoxicity in HEK-293 cell line utilizing Indian gooseberry (Phyllanthus emblica) fruit extract

Antimicrobial resistance (AMR) is a pressing global health challenge that necessitates the search for novel antimicrobial agents and synthetic methodologies. This study investigates the synthesis and antimicrobial efficacy of 25 novel 1,2,4-triazolo[1,5-a]pyrimidine derivatives, catalyzed by Amla (Phyllanthus emblica) fruit juice, which is rich in organic acids and polyphenolic compounds, thus serving as an environmentally sustainable catalyst, in adherence to green chemistry principles. The synthesis is achieved through a one-pot, solvent-free process that yields high quantities of the desired compounds in significantly less time compared to traditional methods. Comprehensive antimicrobial evaluation was conducted against a range of clinically relevant microorganisms, including Chromobacterium violaceum, Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Candida albicans, Cryptococcus neoformans and Aspergillus niger. Concurrently, cytotoxic assays were performed on HEK-293 cells, to assess safety profiles, revealing that compounds B-1, B-6, B-7, B-14 and B-15 exhibited potent antimicrobial activity while maintaining low cytotoxicity and high cell viability. These findings underscore the therapeutic potential of the synthesized compounds in combatting infectious diseases and addressing the challenges posed by AMR, highlighting the critical importance of dose optimization in therapeutic applications. This study combats contagious diseases, mitigates AMR challenges and contributes significantly to the field of antimicrobial drug discovery, emphasizing the need for sustainable synthetic strategies that align with future pharmaceutical endeavors. Our research not only advances the understanding of these novel compounds but also supports ongoing efforts to develop safe and effective therapies against resistant pathogens.

Synthesis, DFT investigation, molecular docking analysis, ADMET studies, and biological evaluation of a novel series of imidazolidinone derivatives as potential antimicrobial agents

In this study, we constructed twenty novel imidazolidinone derivatives via the reaction of 2-(methylthio)-3,5-dihydro-4H-imidazol-4-one derivatives (1a-c) with some active methylene reagents and nitrogen nucleophiles. The synthesized compounds were confirmed through spectral analysis such as 1H NMR, 13C NMR, FT-IR, and MS. Moreover, the synthesized compounds were optimized and utilizing the DFT/B3LYP/6-31(G) basis set to investigate their energies and the presence of two forms of isomers (E and Z). The results confirmed the stability of the E form. ADMET of new imidazolidinones was also studied to investigate their lipophilicity and Lipinski's rule for determination of their physiological biological analysis. Also, the antimicrobial activity of new compounds on Escherichia coli, Klebsiella pneumonia, Staphylococcus aureus, Streptococcus mutans, Candida albicans, and Aspergillus Nigar using the inhibition zone technique were evaluated. The results demonstrate that compound 11c showed higher activity rather than other compounds due to the presence of piperazine moiety out of the plane of the benzene ring. Additionally, the docking study showed an electrostatic bonding interaction of the hydrogen of 11c and the amino acids of two proteins such as PDBID: 3t88 and 2wje.

Phage-derived polysaccharide depolymerase potentiates ceftazidime efficacy against Acinetobacter baumannii pneumonia via low-serum-dependent mechanisms

The emergence of multidrug-resistant Acinetobacter baumannii (MDR-AB), which most commonly manifests as pneumonia, has posed significant clinical challenges and called for novel treatment strategies. Phage depolymerases, which degrade bacterial surface carbohydrates, have emerged as potential antimicrobial agents. However, their preclinical application is limited to systemic infections due to their dependency on serum-mediated bacterial killing. To extend the treatment paradigm of depolymerase to low-serum lung infections, we explored the feasibility of applying phage depolymerase to potentiate antibiotic efficacy in controlling MDR-AB pneumonia. Using a model depolymerase, Dpo71, we observed that it could effectively potentiate antibiotic efficacy against MDR-AB2 bacteria in low-serum conditions mimicking lung milieu but showed no adjuvant effect in serum-free conditions. Unprecedentedly, we reported this low-serum-dependent mechanism that polysaccharide-degrading enzyme Dpo71 exposed bacteria to serum-induced membrane permeabilization and oxidative phosphorylation pathway inhibition, leading to a weakened ATP-dependent efflux pump and strengthened ROS-induced membrane permeabilization. These joint effects facilitated antibiotic (ceftazidime, CFZ) binding, ultimately exerting bactericidal effects. Resultantly, the bacterial load in the lungs of the Dpo71-CFZ combination group was significantly reduced compared with the Dpo71-alone and CFZ-alone groups. Overall, this study unravels the low-serum-dependent mechanisms by which depolymerase potentiated antibiotic efficacy, highlighting its potential as a novel strategy to enhance antibiotic activity against severe pneumonia.

Progress of photoantibiotics in overcoming antibiotic resistance.

Antibiotic resistance has emerged as a global public health crisis in the 21st century, leading to treatment failures. To address this issue, the medical and pharmaceutical sectors are confronted with two challenges: i) finding potent new antimicrobial agents that would work against resistant-pathogens, and ii) developing conceptually new or unconventional strategies by which a particular antibiotic would remain effective persistently. Photopharmacology with the aid of reversibly controllable light-active antibiotics that we call "photoantibiotics" shows great promise to meet the second challenge, which has inspired numerous research laboratories worldwide to align their research in inventing or developing such antibiotics. In this review, we have given an overview of the progress made over the last ten years or so towards developing such photoantibiotics. Although making such antibiotics that hold high antimicrobial potency like the native drugs and subsequently maintain a significant activity difference between light irradiated and non-irradiated states is very challenging, the progress being reported here demonstrates the feasibility of various approaches to engineer photoantibiotics. This review provides a future perspective on the use of such antibiotics in clinical practice with the identification of potential problems and their solutions.

Tryptamine‐Derived Schiff Bases: Potent Antimicrobial Agents and Evaluation of Cytotoxicity, ADME and DNA Binding Properties

Inspired by the fact that the introduction of indole pharmacophore in organic scaffolds could enable interesting pharmacological properties, the series of novel tryptamine‐derived Schiff bases was synthetized. Tryptamine was used as a source of indole pattern, as well as an example of biogenic amines which chemical transformations lead to the compounds with prominent biological activities. The obtained results for antimicrobial activity against a range of bacterial and fungal strains and cytotoxic activities have revealed that Schiff base TSB4 combining the tryptamine and p‐nitro aryl patterns in the structure showed better antifungal activity at low concentrations than standard drug Fluconazole, while compound TSB6 with molecular scaffold composed from tryptamine and quinoline moieties showed certain cytotoxic effect on HCT‐116 cell line with a strongly expressed selectivity about healthy fibroblast cells, MRC‐5. For these two selected compounds, additional ADME analysis and DNA interactions were performed. to obtain better insight into their pharmacokinetics and determination of binding mode for DNA molecules. As results suggested, strong binding of examined compounds to CT‐DNA was observed, while the ADME screening showed that selected compounds possess suitable physicochemical properties for oral bioavailability and druglikeness.

Evaluation of anti-biofilm and anti-virulence effect of zinc sulfate on Staphylococcus aureus isolates

Staphylococcus aureus produces a plethora of virulence factors to invade and establish infections in the host system, and biofilms are more resistant to antibiotics than planktonic cells. In this study, we aimed to investigate the anti-virulence and anti-biofilm potentials of zinc sulfate against S. aureus isolates. The synergistic effect of zinc sulfate in combination with antibiotics on S. aureus was characterized using the checkerboard method. The influence of zinc sulfate on biofilm formation and virulence factors production by S. aureus was experimentally assessed. RT-qPCR was used to investigate the effect of zinc sulfate on the expression of biofilm-related genes. Zinc sulfate exhibited good antibacterial activity against S. aureus with a MIC of 128 µg/ml against all tested isolates. Also, the findings indicate a synergistic effect of a combination of zinc sulfate and antibiotics against the tested isolates. Zinc sulfate at 256 µg/ml concentration inhibited biofilm formation for all isolates. The expression of biofilm-related genes was significantly repressed in zinc sulfate-treated bacteria compared to untreated cells. Zinc sulfate could inhibit the hemolytic ability of S. aureus. Moreover, zinc sulfate-treated bacteria exhibited a significant decrease in coagulase and catalase activity relative to control untreated S. aureus. Our results support that zinc sulfate is a potential antimicrobial and anti-virulence agent against S. aureus infections.

Bone Healing via Carvacrol and Curcumin Nanoparticle on 3D Printed Scaffolds.

Carvacrol is a potent antimicrobial and anti-inflammatory agent, while curcumin possesses antioxidant, anti-inflammatory, and anticancer properties. These phytochemicals have poor solubility, bioavailability, and stability in their free form. Nanoencapsulation can reduce these limitations with enhanced translational capability. Integrating nanocarriers with 3D-printedcalcium phosphate (CaP)scaffolds presents a novel strategy for bone regeneration. Carvacrol and curcumin-loaded nanoparticles (CC-NP) synthesized with melt emulsification produced negatively charged, monodispersed particles with a hydrodynamic diameter of ≈127nm. Their release from the scaffold shows a biphasic release under physiological and acidic conditions. At pH 5.0, the CC-NP exhibits a 53% release of curcumin and nearly 100% release of carvacrol, compared to 19% and 36% from their respective drug solutions. At pH 7.4, ≈40% of curcumin and 76% of carvacrol releases, highlighting their pH-sensitive release mechanism. In vitro studies demonstrate a 1.4-fold increase in osteoblast cell viability with CC-NP treatment. CC-NP exhibit cytotoxic effects against osteosarcoma cells, reducing cell viability by ≈2.9-fold. The antibacterial efficacy of CC-NP evaluated against Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA) exhibiting 98% antibacterial efficacy. This approach enhances therapeutic outcomes and minimizes the potential side effects associated with conventional treatments, paving the way for innovative applications in regenerative medicine.

Unraveling the therapeutic potential of Satureja nabateorum extract: inducing apoptosis and cell cycle arrest through p53, Bax/Bcl-2, and caspase-3 pathways in human malignant cell lines, with in silico insights

Satureja nabateorum, known as Nabatean savory is a Lamiaceae plant native to the Arabian Peninsula, specifically in the mountainous regions of Saudi Arabia. The study aims to investigate the phytochemical components of the S. nabateorum leaves (SNL) and stems (SNS) extract and to assess their antioxidant, antimicrobial, and antiproliferative properties. Methanol extracts from leaves and stems were analyzed for chemical constituents using the GC-MS technique. Antioxidant capacities were measured using hydrogen peroxide and ABTS radical-scavenging methods, and antimicrobial activity was tested against various microorganisms. Cytotoxic activity on four human malignant cell lines was assessed using MTT and flow cytometry. Molecular docking and molecular dynamics studies were conducted to understand the interactions and binding modes of the extracted compounds at a molecular level. GC-MS analysis of SNL extract revealed thymol, carvacrol, and p-cymen-8-ol as major constituents. SNS extract contained β-sitosterol, stigmasterol, lupeol, and lup-20(29)-ene-3β,28-diol. SNS extract exhibited more potent antioxidant, antimicrobial, and anticancer effects than SNL extract. The extract, SNS, exhibited potential toxicity in A549 cells with an IC50 value of 3.62 µg/mL and induced marked apoptotic effects with S phase-cell cycle arrest. SNS extract also showed higher levels of Caspase 3, Bax, p53, and the Bax/Bcl2 ratio and lower levels of Bcl-2. Molecular docking and dynamic simulation supported these findings, targeting the EGFR TK domain. The study suggests that the S. nabateorum stem extract holds promise as a potent antimicrobial, antioxidant, and anticancer agent. It provides valuable insights for considering the extract as a substitute for chemotherapy and/or protective agents.

Valorization of oil refinery by-products: production of sophorolipids utilizing fatty acid distillates and their potential antibacterial, anti-biofilm, and antifungal activities.

Starmerella bombicola is a native yeast strain producing sophorolipids as secondary metabolites. This study explores the production, characterization, and biological activities of sophorolipids and investigates the antimicrobial, anti-biofilm, and antifungal properties of sophorolipids produced from oil refinery wastes by the yeast Starmerella bombicola. The present work demonstrated that S. bombicola MTCC 1910 when grown in oil refinery wastes namely palm fatty acid distillates and soy fatty acid distillates enhanced the rate of sophorolipids production drastically in comparison to vegetable oil, sunflower oil used as hydrophobic feedstock. Sophorolipid yields were 18.14, 37.21, and 46.1g/L with sunflower oil, palm, and soy fatty acid distillates respectively. The crude biosurfactants were characterized using TLC, FTIR, and HPLC revealing to be acetylated sophorolipids containing both the acidic and lactonic isomeric forms. The surface lowering and emulsifying properties of the sophorolipids from refinery wastes were significantly higher than the sunflower oil-derived sophorolipids. Also, all the sophorolipids exhibited strong antibacterial properties (minimum inhibitory concentrations were between 50 and 200µgmL-1) against Salmonella typhimurium, Bacillus cereus, and Staphylococcus epidermidis and were validated with morphological analysis by Scanning electron microscopy. All the sophorolipids were potent biofilm inhibitors and eradicators (minimum biofilm inhibitory and eradication concentrations were between12.5to1000µgmL-1) for all the tested organisms. Furthermore, antifungal activities were also found to exhibit about 16-56% inhibition at 1mgmL-1 for fungal mycelial growth. Therefore, this endeavour of sophorolipids production using palm and soy fatty acid distillates not only opens up a window for the bioconversion of industrial wastes into productive biosurfactants but also concludes that sophorolipids from oil refinery wastes are potent antimicrobial, anti-biofilm, and antifungal agents, highlighting their potential in biotechnological and medical applications.

An efficient synthesis, characterization, and in silico studies of novel chromenes, thiophenes, pyrazolo[1,5-a]pyrimidines, and pyrimidines as potential antimicrobial and anticancer agents using the bio-buffer tris(hydroxymethyl)aminomethane (THAM)

Novel 2-imino-6-(aryldiazenyl)-2H-chromene-3-carboxamides 6a–e, 2-amino-4H-cyclopenta or benzo[b]thiophene-3-carboxamides 10a,b, 2,7-diaminopyrazolo[1,5-a]pyrimidine-6-carboxamides 13a–e, pyrimidine-5-carboxamides 14, 15 and 3-amino-1H-pyrazole-4-carboxamide 16 were synthesized from the reaction of 2-cyano-N-(1,3-dihydroxy-2-(hydroxyl-methyl) propan-2-yl) acetamide 2 with 4-arylazosalicylaldehydes 5a-e, cyclopentanone and/or cyclohexanone, guanidine derivatives and hydrazine hydrate, respectively. Some new compounds were evaluated for antibacterial activity in vitro, and exhibited good efficacy compared to gentamicin. Compound 4c showed greater activity against gram negative bacteria (Klebsiella pneumonia and Pseudomonas aeruginosa) than standard antibiotic. Compound 4c with two withdrawing groups also showed the higher activity (38.7 ± 0.6) against fungi (Candida albicans) than the Nystatin (20 ± 0.5). On the other hand, compounds 13a, 13c, and 13e have strong cytotoxic activity among the tested compounds in the three selected cancer cell lines (HePG2, MCF7 and Hela). Physicochemical characterization by Swiss ADME predication was also performed for some synthesized compounds exhibiting better biological and antimicrobial properties.

Screening of synthesized perimidine compounds for the assessment of antimicrobial potential: in-vitro and in-silico molecular docking and molecular dynamics simulation studies

Presently, antimicrobial resistance is a major and worldwide concern due to high rate of mutation in microorganisms, widespread use, lack of efficacy of drugs, and low drug discovery rate. Considering the importance of N-heterocycles as antibiotics, perimidine derivatives 3(a–v) have been synthesized via cyclocondensation reaction of 1,8-diaminonaphthalene and aryl aldehydes. Further, the synthesized perimidines 3(a–v) were screened as potent antimicrobial agents via in-vitro, in-silico, ADME and MD simulation studies. All 22 derivatives 3(a–v) were studied against two-gram +ve (E. coli and P. aeruginosa), two-gram −ve (S. aureus and B. subtilis), and two fungal (A. niger and S. cerevisiae) strains using ciprofloxacin and fluconazole as reference drugs. The in-vitro study results showed that compounds 3e, 3h, 3l, and 3m were the most potent against S. aureus and 3(a–d), 3(g–i), and 3s were the most active against B. subtilis as compared to the standard. Furthermore, molecular docking studies were performed against Dihydrofolate reductase (PDB Id: 3SRW) from S. aureus, DNA gyrase (PDB Id: 4DUH) from E. coli, and ERG11 gene (PDB Id: 4LXJ). Compounds 3f, 3f/3m, and 3o were found to bind efficiently with the highest binding energy − 10.6, − 9.6, and − 11.3kcal/mol depicting the potential inhibitor of 3SRW, 4DUH, and 4LXJ receptor protein, respectively. The drug-likeness properties of compounds were studied using SwissADME program. To further validate these findings, molecular dynamics simulations were conducted to evaluate their binding stability. From simulation studies, it was observed that all the shortlisted compounds displayed stable binding within the active site of the selected proteins.Graphical abstract

Synthesis and biological evaluation of some new heterocyclic compounds incorporating sulfapyridine as potential antimicrobial agents

This study investigated the cyanoacylation of the sulfapyridine moiety using cyanoacetyl pyrazole as a key synthetic intermediate for the construction of diverse bioactive scaffolds. The intermediate, 2-cyano-N-(4-(N-pyridin-2-yl) sulfamoyl) phenylacetamide, served as a valuable precursor for the synthesis of acrylamide, thiophene, thiazole, chromene, pyridone, 1,2,4-triazine, and hydrazone derivatives all incorporating the sulfapyridine core. The structural elucidation of the synthesized compounds was achieved using infrared (IR), nuclear magnetic resonance (1H and 13C), and mass spectrometry techniques. The biological activity of the newly synthesized compounds was evaluated against a panel of microorganisms, including Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis), Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa), and the fungus Candida albicans. Notably, the thiol derivative (compound 12), the pyrazole derivative (compound 15), and the 1,2,4-triazine derivatives (compound 21) exhibited significant to good antibacterial and antifungal activity. Interestingly, compounds 12 and 15 displayed a broader spectrum of activity, demonstrating efficacy against all tested microbial strains.

Synthesis, In Vitro and In Silico Evaluation of 3-(4, 5-Diphenyl-4H-1,2,4-triazol-3-yl)pyridine Derivatives As Potential Antimicrobial Agents

Synthesis, In Vitro and In Silico Evaluation of 3-(4, 5-Diphenyl-4H-1,2,4-triazol-3-yl)pyridine Derivatives As Potential Antimicrobial Agents

Design, synthesis, and evaluation of some metal ion complexes of mannich base derived from 2-Mercaptobenzimidazole as potential antimicrobial agents

This study aims to prepare new compounds and investigate them spectroscopically and biologically against selected types of positive and negative bacteria and fungi to demonstrate their biological effectiveness. The prepared ligand combining formaldehyde, indole, sulfa benzamide, and 2-mercapto benzimidazole, a Mannich base ligand (L) was synthesized. The six metal ions including Cobalt (II), Nickel (II), Copper (II), Palladium (II), Platinum (IV), and gold (III) have interacted with the ligand and formed new complexes. Different spectroscopic methods, including C.H.N.S., FTIR, UV- Range visible, 1HNMR, 13CNMR, mass spectra, magnetic moment, and molar conductivity were used to suggest the new geometry of the complexes. The result from the infrared spectrum showed that the ligand behaves as tridentate with all prepared complexes. Conductivity analysis revealed the electrolytic nature of palladium, platinum, and gold ions complexes and non-electrolytes. The antibacterial activity of the compounds that were produced was tested using an agar-well diffusion procedure towards two strains of gram-positive as well as two strains of gram-negative bacteria and fungi (Staphylococcus, Streptococcus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans) respectively at 0.02M. The standard (∆Eo) and (∆Hfo) of ligand and six complexes were calculated using the program Hyper chem 8.0.7. The research established that complexes are more stable than ligands. Calculated HOMO and LUMO and vibration frequencies using (parametric method 3 (PM3)) to find out the active sites in the ligand showed that they can coordinate and note the extent to which the results of theoretical vibrational frequencies are close to the process when calculating the vibrational frequency of the active aggregates.

Unveiling the power of TiO2 doped ZnO nanomaterial as an effective antimicrobial solution in the leather industry

The surface protection of leather supplies is a major concern worldwide due to its susceptibility to microbial growth. Different methods are employed to protect leather, their results ends up with the environmental pollution and human safety issues. Nanoparticles with excellent antimicrobial potential can provide sustainable protection to leather accessories. The present work represented a comprehensive investigation into the preparation and characterization of titanium dioxide-doped zinc oxide (ZnO/TiO2 NPs) nanoparticles and their exploring as a potential antimicrobial agent in the leather industry. ZnO nanoparticles were synthesized through Sol-gel method by the reduction of zinc acetate dihydrate via black cardamom seed's extract and subsequently doped with TiO2. The optical, structural, and morphological features of nanoparticles were thoroughly scrutinized through UV–visible spectroscopy, XRD, FT-IR, and SEM-EDAX. The UV–visible spectrum showed enhanced performance between 300 and 350 nm and various peaks of the FT-IR spectrum, i.e. 3315.53, 1566.20, 1402.25, 1340.53, 1014.56, 921.97, 690.52, and 677.01 cm−1, revealed chemical bonds that prove the correct doping of TiO2 in ZnO nanoparticles. The characteristic peaks obtained from XRD at 2Ө of 32°, 35.5°, 37.2°, 47.9°, 55.6° 63.51°, and 70° intimated to the crystal planes of (100), (002), (101), (102), (110), (103), and (112), respectively. SEM-EDAX images revealed the roughly spherical but agglomerated structure of nanoparticles with size 45.44 nm. Furthermore, minimum inhibitory concentration (MIC), antimicrobial potential, and anti-biofilm potential analyses of nanoparticles, against all selected microorganisms (Aspergillus niger, Staphylococcus aureus, and Escherichia coli) provided valuable insights into physical and biological properties of the nanoparticles. The clear zones of inhibition (29–30 mm) against these pathogenic strains showed exceptional antimicrobial action of the ZnO/TiO2 NPs. Overall, these results provide an approachable method to synthesize ZnO/TiO2 nanoparticles and their antimicrobial ability will prove to be beneficial for the protection of leather materials from various microbial contaminations.