Search Results (208)

Root rot, mainly caused by Fusarium oxysporum, is one of the most destructive diseases and leads to significant economic loss of Astragalus membranaceus. To develop an effective strategy for the management of this serious disease, a bacterial strain 2-12 was screened from A. membranaceus rhizosphere soil and identified as Bacillus paralicheniformis based on the phylogenetic analyses of gyrase subunit B gene (gyrB) and RNA polymerase gene (rpoB) sequences. Interestingly, the volatile organic compounds (VOCs) produced by B. paralicheniformis 2-12 exhibited potent antifungal activities against F. oxysporum, as well as fifteen other plant pathogens. Under scanning electron microscopy observation, hyphae treated with the VOCs exhibited abnormal variation such as distortion, twist, and vesiculation, leading to distinctive protoplasm shrinkage. After treatment with B. paralicheniformis 2-12 VOCs, the lesion diameter and disease incidence both reduced significantly compared to control (p < 0.05), thus demonstrating prominent biological efficiency. Moreover, B. paralicheniformis 2-12 VOCs were composed of 17 VOCs, including 9 alkanes, 3 alcohols, 3 acids and esters, 1 aromatic compound, and 1 alkyne compound. A total of 1945 DEGs, including 1001 up-regulated and 944 down-regulated genes, were screened via transcriptome analysis. These DEGs were mainly associated with membranes and membrane parts, amino acid metabolism, and lipid metabolism. The findings in this work strongly suggested that B. paralicheniformis 2-12 VOCs could be applied as a new candidate for the control of A. membranaceus root rot. Full article

Background/Objectives: Among Enterobacterales, OXA-48-like-producing Proteus mirabilis strains have been scarcely detected. Herein, we characterized a bla_OXA-48-harbouring P. mirabilis strain recovered from Greece (Pm GR-1), while phylogenomics and comparative genomics analyses with previously published bla_OXA-48 carriers were also assessed. Methods: Characterization of Pm GR-1 was performed by the Vitek^® Compact and Mass Spectrometry systems, antimicrobial susceptibility testing, detection of beta-lactamases, multilocus-sequence typing (MLST), and whole-genome sequencing (WGS). In silico prediction of mobile genetic elements (MGEs), genomic islands (GIs), antimicrobial resistance genes (ARGs) and virulence factors (VFs), and phylogenetic, core-genome SNP and comparative genomics analyses were executed using bioinformatic tools. Results: Pm GR-1 was isolated from a urine sample of an outpatient in a Greek hospital. It exhibited a multidrug-resistant phenotype, being susceptible only to amikacin and ceftazidime/avibactam. It co-carried several beta-lactamase genes on the chromosome (bla_OXA-48, bla_CTX-M-14, bla_TEM-1) and a plasmid (bla_TEM-2) and several other ARGs, but also mutations associated with quinolone resistance in the DNA gyrase and topoisomerase IV subunits. It belonged to the international clone ST135 that has also been detected among OXA-48-producing P. mirabilis strains from Germany and the USA. Pm GR-1 was genetically related to those from Germany, sharing highly similar MGEs, GIs, ARGs and VFs, including the chromosomal bla_OXA-48 genetic structure, the O-antigen locus, the flagella locus, the MR/P fimbriae operon, and the urease gene cluster. Conclusions: To our knowledge, this is the first report from Greece of a bla_OXA-48-possessing P. mirabilis strain. The emergence of bla_OXA-48 among P. mirabilis strains of the international clone ST135 in different geographical regions is worrying. Close monitoring of these strains is required in One Health settings. Full article

Cancer remains one of the leading causes of death globally, highlighting the urgent need for novel anticancer therapies with higher efficacy and reduced toxicity. Similarly, the rise in multidrug-resistant pathogens and emerging infectious diseases underscores the critical demand for new antimicrobial agents that target resistant infections through unique mechanisms. This study used computational approaches to investigate twenty quinolone–triazole and conazole–triazole hybrid derivatives as antimicrobial and anticancer agents (1–20) with nine reference drugs. By studying their interactions with 6 bacterial DNA gyrase and 10 cancer-inducing target proteins (E. faecalis, M. tuberculosis, S. aureus, E. coli, M. smegmatis, P. aeruginosa and EGFR, MPO, VEGFR, CDK6, MMP1, Bcl-2, LSD1, HDAC6, Aromatase, ALOX15) and comparing them with established drugs such as ampicillin, cefatrizine, fluconazole, gemcitabine, itraconazole, ribavirin, rufinamide, streptomycin, and tazobactam, compounds 15 and 16 emerged as noteworthy antimicrobial and anticancer agents, respectively. In molecular dynamics simulations, compounds 15 and 16 had the strongest binding at −10.6 kcal mol⁻¹ and −12.0 kcal mol⁻¹ with the crucial 5CDQ and 2Z3Y proteins, respectively, exceeded drug-likeness criteria, and displayed extraordinary stability within the enzyme’s pocket over varied temperatures (300–320 K). In addition, we used density functional theory (DFT) to calculate dipole moments and molecular orbital characteristics and analyze the thermodynamic stability of putative antimicrobial and anticancer derivatives. This finding reveals a well-defined, possibly therapeutic relationship, supported by theoretical and future in vitro and in vivo studies. Compounds 15 and 16, thus, emerged as intriguing contenders in the fight against infectious diseases and cancer. Full article

Background/Objectives: Mycobacterium avium, a member of Mycobacterium avium complex (MAC), is an emerging opportunistic pathogen causing MAC-pulmonary disease (PD). Fluoroquinolones (FQs), along with ethambutol (EMB) and rifampicin, are recommended for macrolide-resistant MAC-PD; however, FQ-resistant M. avium have been reported worldwide. WQ-3810 is an FQ with high potency against FQ-resistant pathogens; however, its activity against M. avium has not yet been studied. Methods: In this study, we conducted a DNA supercoiling inhibitory assay to evaluate the inhibitory effect of WQ-3810 on recombinant wild-type (WT) and four mutant DNA gyrases of M. avium and compared the IC₅₀s of WQ-3810 with those of ciprofloxacin (CIP), levofloxacin (LVX), and moxifloxacin (MXF). In addition, we examined WQ-3810’s antimicrobial activity against 11 M. avium clinical isolates, including FQ-resistant isolates, with that of other FQs. Furthermore, we assessed the synergistic action of WQ-3810 with the combination of either EMB or isoniazid (INH). Results: In a DNA supercoiling inhibitory assay, WQ-3810 showed 1.8 to 13.7-fold higher efficacy than LVX and CIP. In the MIC assay, WQ-3810 showed 4 to 8-fold, 2 to 16-fold, and 2 to 4-fold higher antimicrobial activity against FQ-resistant isolates than CIP, LVX, and MXF, respectively. The combination of WQ-3810 and INH exhibited a synergistic relationship. Conclusions: The overall characteristics of WQ-3810 demonstrated greater effectiveness than three other FQs, suggesting that it is a promising option for treating FQ-resistant M. avium infections. Full article

Most studies on the Arthrosphaera genus, or giant pill millipedes, focus on its taxonomy, distribution, and ecology. Therefore, this investigation aimed to explore the chemical composition and bioactive properties of the hemolymph of the giant pill millipede Arthrosphaera lutescens (Butler, 1872). Chemical characterization of hemolymph was performed using gas chromatography–mass spectrometry (GC-MS) and liquid chromatography–quadrupole time-of-flight mass spectrometry (LC-MS Q-TOF), revealing a complex array of over 200 compounds. The bioactive properties of hemolymph were determined by using radical scavenging capacity (DPPH assay); antibacterial activity against human pathogens like Escherichia coli (Migula, 1895) Castellani and Chalmers 1919, Klebsiella pneumonia (Schroeter, 1886) Trevisan 1887, and Staphylococcus aureus (Rosenbach, 1884); and cytotoxicity against Dalton’s lymphoma ascites (DLA) cells using the trypan blue assay. The hemolymph showed radical scavenging properties and antibacterial and cytotoxic activity. Among the identified metabolites, 1,2-dimethoxy-13-methyl-[1,3]benzodioxolo[5,6-c]phenanthridine (DMBP) emerged as a promising candidate due to its high abundance and bioactivity profile, showcasing therapeutic potential against both lymphoma and S. aureus in further docking studies. Computational analysis identified key T-cell lymphoma targets, with molecular docking suggesting DMBP’s anticancer properties through interactions with proteins like AKT1 and mTOR. Additionally, docking revealed DMBP’s antibacterial effects via interactions with proteins such as Sortase-A and DNA gyrase. This research underscores the potential pharmaceutical applications of metabolites from giant pill millipedes. Full article

The World Health Organization notes that some bacteria have been demonstrated to possess significant public health risks; they have antibiotic resistance, and there are fewer alternatives for control. The n-hexane extract and cinaguaiacin obtained from Artemisia cina show promising antibacterial activity, including against multidrug-resistant bacteria that affect animal and human health. Objective: The aim of this study was to determine the antibacterial activity of the n-hexane extract of A. cina and cinaguaiacin against multidrug-resistant bacteria. Methods:A. cina was collected in the pre-flowering period, the n-hexane extract was obtained, and chromatographic techniques and structure were used to separate the lignans, which were elucidated with nuclear magnetic resonance techniques. Four ATCC strains were used, and four strains were isolated from clinical cases with different resistance profiles. The antibacterial activity was determined by calculating the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC), the time-kill kinetics assay, and the cell membrane integrity and DNA release assay. Molecular docking studies of lignans demonstrated the binding mode involved in the active site of DNA gyrase B. Results: The n-hexane extract inhibited growth against 87.5% of the strains tested (MIC 5.31 to 42.5 mg/mL) and showed bactericidal activity against 25% of the strains tested (MBC 0.62 to 85 mg/mL). Cinaguaiacin inhibited growth against 100% of the strains tested (MIC, 0.56 to 2.25 mg/mL) and exhibited bactericidal activity against 25% of the strains tested (MBC, 0.62 to 85 mg/mL). Conclusions: The mechanism of cinaguaiacin’s action may be associated with damage to the plasma membrane, as the protein and DNA levels were higher than those of the positive control. The n-hexane extract and cinaguaiacin obtained from A. cina showed a bacteriostatic or bactericidal effect, depending on the strain evaluated. Full article

Tuberculosis (TB) remains one of the leading causes of mortality worldwide, exacerbated by the emergence of multidrug-resistant (MDR) and extensively drug-resistant (XDR) Mycobacterium tuberculosis strains. In the pursuit of novel therapeutic strategies, thiazolidin-4-one derivatives have gained significant attention due to their structural diversity and broad-spectrum biological activities. This review provides a comprehensive summary of recent advances (2021–present) in the synthesis, structure–activity relationship (SAR), and mechanisms of action of thiazolidin-4-one derivatives as promising antitubercular agents. A detailed discussion of synthetic pathways is presented, including classical and multi-component reactions leading to various subclasses such as thiazolidine-2,4-diones, rhodanines, and pseudothiohydantoins. The SAR analysis highlights key functional groups that enhance antimycobacterial activity, such as halogen substitutions and heterocyclic linkers, while molecular docking and in vitro studies elucidate interactions with key Mtb targets including InhA, MmpL3, and DNA gyrase. Several compounds demonstrate potent inhibitory effects with MIC values lower than or comparable to first-line TB drugs, alongside favorable cytotoxicity profiles. These findings underscore the potential of thiazolidin-4-one scaffolds as a valuable platform for the development of next-generation antitubercular therapeutics. Full article

This study investigated the phytochemical composition and biological activities of Myrtus communis essential oil (EO) from Algeria, focusing on its antimicrobial, antifungal, and insecticidal properties using in vitro and in silico approaches. Gas chromatography–mass spectrometry (GC-MS) analysis identified myrtenyl acetate (57.58%), 1,8-cineole (17.82%), and α-terpineol (6.82%) as the major constituents. M. communis EO exhibited significant antibacterial activity, particularly against Staphylococcus aureus (13.00 ± 0.70 mm) and Salmonella typhimurium (13.00 ± 1.50 mm), with moderate inhibition of Bacillus subtilis (10 ± 1.00 mm) and Escherichia coli (9.00 ± 0.70 mm), while Pseudomonas aeruginosa showed resistance. The antifungal activity was notable against Fusarium oxysporum (16.50 ± 0.50 mm), Aspergillus fumigatus (11.00 ± 1.00 mm), and Penicillium sp. (9.00 ± 0.60 mm) but ineffective against Aspergillus niger. Insecticidal activity against Tribolium castaneum was evaluated using contact toxicity, fumigation toxicity, and repellent activity assays. The EO demonstrated potent insecticidal effects, with an LC₅₀ value of 0.029 µL/insect for contact toxicity and 162.85 µL/L air for fumigation after 96 h. Additionally, the EO exhibited strong repellent activity, achieving 99.44% repellency at a concentration of 0.23 mg/cm² after 24 h. Density functional theory (DFT) calculations provided insights into the molecular geometry and electronic properties of the key bioactive compounds. Molecular docking studies evaluated their binding affinities to bacterial enzymes (DNA gyrase, dihydrofolate reductase6, and Gyrase B) and insecticidal targets (acetylcholinesterase), revealing strong interactions, particularly for geranyl acetate and methyleugenol. These findings highlight M. communis EO as a promising natural antimicrobial and insecticidal agent, with potential applications in plant protection and biopesticide development. Full article

Background: Novel norfloxacin derivatives were synthesized, characterized, and screened for their antibacterial activity against Gram-positive strain S. aureus ATCC 6538 and Gram-negative strains; E. coli ATCC 25923, K. pneumoniae ATCC 10031, and P. aeruginosa ATCC 27853 using the agar cup diffusion method. Results: The results revealed that compounds 6–17 exhibited more potent activity towards S. aureus ATCC 6538 with MIC values of 0.21–3.61 µM than norfloxacin with a MIC of 7.83 µM. The most potent compound, 6, showed 37-fold more potency than norfloxacin. More importantly, compound 7 exhibited more potent activity against MRSA than norfloxacin, with MIC values of 0.80 and 1.96 µM, respectively. Meanwhile, compounds 15 and 16 have potent activity towards the Gram-negative strains with MIC values of 0.20–0.79 µM compared with norfloxacin with a MIC of 0.24 µM. Moreover, the potent compounds showed higher activity towards topoisomerase II enzymes, especially against topoisomerase IV, which confirms the docking study with the S. aureus gyrase enzyme active binding site (PDB ID: 2XCT). In addition, cytotoxicity assays of the most potent compounds showed that compounds 6, 7, 15, and 16 have negligible risks of toxic effects when evaluated against the normal cell line WI 38. Conclusions: The docking study of the most potent compounds 6, 7, 15, and 16 on the gyrase enzyme active site (PDB: 2XCT) aligns their antibacterial activity and topoisomerase inhibition. The physicochemical and pharmacokinetic characteristics of the target derivatives were forecasted via SwissADME. Hence, these compounds are considered promising antibacterial candidates that require further optimization. Full article

Background: Syzygium aromaticum is a tree whose aromatic dried flower buds are known as cloves. When it comes to phenolic chemicals, such as flavonoids, hydroxybenzoic acids, hydroxycinnamic acids, and hydroxyphenyl propane, clove is a major plant source of these substances. Finding out how effective clove buds are as antioxidants was the driving force behind this study’s GC-MS investigation and computational discoveries. Methods: This inquiry into clove pods focused on the chemical composition of clove using the GC-MS technique, as well as its antioxidant qualities and computational modeling. Results: This antioxidant may be more effective in lower doses than ascorbic acid (A.A.), butylate hydroxytoluene (BHT), and β-carotene, with 57.22 ± 0.41 mg QE/g of total phenols and flavonoids and 7.25 ± 0.12 mg GAE/g of clove extract. Phenols destroy free radicals, which boosts antioxidant activity. Flavonoids defend against ROS, which also boosts antioxidant activity. Clove pod GC-MS analysis identified 21 components, of which eugenol accounted for 58.86%. The absence of nitrogen and chlorine molecules emphasizes the composition’s organic nature. Eugenol, the major component of clove oil, is a phenolic molecule that binds strongly to bacterial enzymes such as DNA gyrase and dihydrofolate reductase. Docking experiments have shown that clove chemicals interact with acetylcholinesterase, a crucial enzyme in insect larvae, paralyzing and killing them. Conclusions: This study demonstrates the immense potential of plants in providing novel therapeutic and environmental solutions. We must support further research into nature’s inherent benefits. The extensive knowledge that can be gained from botany can be used to improve health, ecology, and sustainability. Full article

We used molecular docking to determine the binding energy and interactions of apigenin and 16 related flavonoids, with 24 distinct proteins having diverse biological functions. We aimed to identify potential inhibitors of these proteins and understand the structural configurations of flavonoids impacting their binding energy. Our results demonstrate that apigenin exhibits high binding energies (a surrogate for binding affinity or inhibitory potential) to all tested proteins. The strongest binding energy was −8.21 kcal/mol for p38 mitogen-activated protein kinases, while the weakest was −5.34 kcal/mol for cyclin-dependent kinase 4. Apigenin and many other flavonoids showed high binding energies on xanthine oxidase (1.1–1.5 fold of febuxostat) and DNA methyltransferases (1.1–1.2 fold of azacytidine). We uncovered high binding energies of apigenin and certain flavonoids with mutated Kirsten rat sarcoma viral oncogene homolog at G12D (KRAS G12D), G12V, and G12C. Consequently, apigenin and certain flavonoids have the potential to effectively inhibit pan-KRAS oncogenic activity, not just on specific KRAS mutations. Apigenin and certain flavonoids also have high binding energies with aromatase (involved in estrogen production) and bacterial infections, i.e., DNA gyrase B and 3R-hydroxy acyl-ACP dehydratase (FABZ). Our findings are pivotal in identifying specific flavonoids that can effectively inhibit targeted proteins, paving the way for the development of innovative flavonoid-based drugs. Full article

Vitex agnus-castus L., a medicinal plant widespread in the Middle East and Europe, is traditionally used to treat various disorders. In this study, extracts from its leaves, collected in Algeria, were evaluated for their antioxidant, enzymatic, and antibacterial activities through in vitro and in silico studies. The hydroalcoholic extract was fractionated using solvents of varying polarity to isolate bioactive compounds with potential biological effects. Notable levels of total phenolics, flavonoids, and flavonols were detected in the dichloromethane (CH₂Cl₂) and ethyl acetate (EtOAc) extracts. NMR and GC-MS were used to identify metabolites in the extracts, which were discussed in relation to their biological activities. Antioxidant assays showed that the EtOAc extract had a remarkable effect, particularly in the DPPH^• free radicals test (IC₅₀ = 15.68 ± 1.51 μg/mL), while enzymatic assays revealed that the dichloromethane extract moderately inhibited butyrylcholinesterase (IC₅₀ = 133.54 ± 1.45 μg/mL). Antibacterial assays showed that the extracts inhibited the growth of Staphylococcus aureus, Bacillus subtilis, and Escherichia coli strains, with the most significant effect observed for the n-hexane extract, especially against S. aureus and B. subtilis (respectively, 22.33 ± 0.47 and 18.33 ± 0.47 mm diameters). These outcomes were validated via molecular docking simulations on three DNA gyrase enzymes: 3G7E (from E. coli), 3G75 (from S. aureus), and 4DDQ (from B. subtilis), revealing that linolenic and palmitic acids, as well as phytol significantly interacted with these enzymes, showing varying binding affinities and suggesting antibacterial potential against the targeted species E. coli and S. aureus. These findings highlight the potential therapeutic use of V. agnus-castus leaves, encouraging further research into their applicability in the development of plant-derived drugs. Full article

In this work, extracts from the pulp, peel, and seed of Manilkara zapota were obtained via lyophilization and oven drying. Bromatological analyses were performed to investigate variabilities in the nutritional content of fruits after nine post-harvest days. The phytochemical content of fruits was assessed by gas chromatography flame ionization detector (GC-FID), and their biological performance was studied using in vitro antibacterial and antioxidant assays (DPPH and ABTS) and in vivo toxicity models. Molecular docking was implemented to evaluate the interaction between polar compounds from chicozapote fruits with receptors involved in the pathogenesis of bacterial strains. Results revealed that water or soluble solids content did not vary after post-harvest. It was demonstrated that lyophilization or oven-drying approaches influenced the insoluble, total dietary fiber and digestible carbohydrates among samples. According to GC-FID analysis, it was observed that lyophilization and oven-drying methods also altered the content of myristic and pentadecanoic acids among the obtained extracts. It was noted that the antibacterial and antioxidant activities of extracts were weak due to their MIC (>1000 μg/mL) and IC₅₀ (>2000 μg/mL) values. Still, the toxicity of extracts was poor against Artemia salina nauplii. In silico evaluation unveiled that polar compounds in M. zapota fruits possess a high binding affinity towards the DNA gyrase B of the cultured strains. This study expands the scientific evidence regarding the influence of distinct extraction methods on the nutritional and nutraceutical content of native fruits and the importance of considering additional approaches to enhance their bioactivities. Full article

Background: In the era of resistance, the design and search for new “small” molecules with a narrow spectrum of activity that target a protein or enzyme specific to a certain bacterium with high selectivity and minimal side effects remains an urgent problem of medicinal chemistry. In this regard, we developed and successfully implemented a strategy for the search for new hybrid molecules, namely, the not broadly known [2-(3-R-1H-[1,2,4]-triazol-5-yl)phenyl]amines. They can act as “building blocks” and allow for the introduction of certain structural motifs into the desired final products in order to enhance the antistaphylococcal effect. Methods: The “one-pot” synthesis of the latter is based on the conversion of substituted 4-hydrazinoquinazolines or substituted 2-aminobenzonitriles and carboxylic acid derivatives to the target products. The possible molecular mechanism of the synthesized compounds (DNA gyrase inhibitors) was investigated and discussed using molecular docking, and their further study for antistaphylococcal activity was substantiated. Results: A significant part of the obtained compounds showed high antibacterial activity against Staphylococcus aureus (MIC: 10.1–62.4 µM) and 5-bromo-2-(3-(furan-3-yl)-1H-1,2,4-triazol-5-yl)aniline and 5-fluoro-2-(3-(thiophen-3-yl)-1H-1,2,4-triazol-5-yl)aniline, with MICs of 5.2 and 6.1 µM, respectively, approaching the strength of the effect of the reference drug, “Ciprofloxacin” (MIC: 4.7 µM). The conducted SAR and ADME analyses confirm the prospects of the further structural modification of these compounds. The obtained [2-(3-R-1H-[1,2,4]-triazol-5-yl)phenyl]amines reveal significant antimicrobial activity and deserve further structural modification and detailed study as effective antistaphylococcal agents. The SAR analysis revealed that the presence of a cycloalkyl or electron-rich heterocyclic fragment in the third position of the triazole ring was essential for the antibacterial activity of the obtained compounds. At the same time, the introduction of a methyl group into the aniline moiety led to an enhancement of activity. The introduction of halogen into the aniline fragment has an ambiguous effect on the level of antistaphylococcal activity and depends on the nature of the substituent in the third position. Conclusions: Obtained [2-(3-R-1H-[1,2,4]-triazol-5-yl)phenyl]amines reveal significant antistaphylococcal activity and deserve for further detailed study as effective antibacterial agents. Full article

Molecular hybridization, which consists of the combination of two or more pharmacophores into a single molecule, is an innovative approach in drug design to afford new chemical entities with enhanced biological activity. In the present study, this strategy was pursued to develop a new series of 6,7-dimethoxy-4-piperazinylquinoline-3-carbonitrile derivatives (5a–k) with potential antibiotic activity by combining the quinoline, the piperazinyl, and the benzoylamino moieties, three recurrent frameworks in antimicrobial research. Initial in silico evaluations were conducted on the designed compounds, highlighting favorable ADMET and drug-likeness properties, which were synthesized through a multistep strategy, isolated, and fully characterized. The whole set was tested in vitro against Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 10145 representative Gram-positive and Gram-negative strains, respectively. Notably, 5k exhibited potent and selective activity against S. aureus (MIC 10 μM), with a dose- and time-dependent response and capability to affect cell membrane integrity. On the other hand, no significant activity was observed against P. aeruginosa. Further in silico docking and molecular dynamics studies highlighted strong interactions of 5k with bacterial enzymes, such as tyrosyl-tRNA synthetase, pyruvate kinase, and DNA gyrase B, suggesting potential modes of action. These findings underscore the value of the hybridization approach in producing new antimicrobial agents, guiding future optimization for broader-spectrum activity. Full article