Search Results (1,630)

Bee products, in particular honey, propolis and bee venom, are of growing scientific interest due to their broad spectrum of antimicrobial activity. In the face of increasing antibiotic resistance and the limitations of conventional therapies, natural bee-derived substances offer a promising alternative or support for the treatment of infections. This paper summarizes the current state of knowledge on the chemical composition, biological properties and antimicrobial activity of key bee products. The main mechanisms of action of honey, propolis and bee venom are presented, and their potential applications in the prevention and treatment of bacterial, viral and fungal infections are discussed. Data on their synergy with conventional drugs and prospects for use in medicine and pharmacology are also included. The available findings suggest that, with appropriate standardization and further preclinical and clinical analyses, bee products could become an effective support for the treatment of infections, especially those caused by pathogens resistant to standard therapies. Full article

The growing demand for food and the environmental impact of conventional agriculture have prompted the search for sustainable alternatives. Phycocyanin (PC) and total phenolic compounds (TPC) extracted from Spirulina platensis have shown potential for the biological control of phytopathogens. The extraction method directly influences the yield and stability of these compounds. This study aimed to establish an efficient extraction protocol for PC and TPC and to evaluate their antimicrobial efficacy in vitro against Colletotrichum orchidearum, Fusarium nirenbergiae, and Alternaria sp. isolated from hydroponically grown lettuce. The phytopathogens were identified based on phylogenetic analyses using sequences from the ITS, EF1-α, GAPDH, and RPB2 gene regions. This is the first report of C. orchidearum in hydroponic lettuce culture in Brazil, expanding its known host range. Extracts were obtained using hydroalcoholic solvents and phosphate buffer (PB), combined with ultrasound-assisted extraction (bath and probe). The extracts were tested for in vitro antifungal activity. Data were analyzed by ANOVA (p < 0.05), followed by Tukey’s test. The combination of the PB and ultrasound probe resulted in the highest PC (95.6 mg·g⁻¹ biomass) and TPC (21.9 mg GAE·g⁻¹) yields, using 10% (w/v) biomass. After UV sterilization, the extract retained its PC and TPC content. The extract inhibited C. orchidearum by up to 53.52% after three days and F. nirenbergiae by 54.17% on the first day. However, it promoted the growth of Alternaria sp. These findings indicate that S. platensis extracts are a promising alternative for the biological control of C. orchidearum and F. nirenbergiae in hydroponic systems. Full article

This study investigated white wastewater (WW) as a potential source of antimicrobial peptides, employing hydrolysis with Pronase E followed by separation through electrodialysis with ultrafiltration membranes (EDUF) to increase the value of dairy components within a circular economy framework. The WW hydrolysate was divided into two key fractions: the cationic recovery compartment (CRC) and the anionic recovery compartment (ARC). The EDUF process effectively separated peptides, with peptide migration rates reaching 6.83 ± 0.59 g/m²·h for CRC and 6.19 ± 0.66 g/m²·h for ARC. Furthermore, relative energy consumption (REC) increased from 1.15 Wh/g to 2.05 Wh/g over three hours, in line with trends observed in recent studies on electrodialysis energy use. Although 29 peptides were statistically selected from the CRC (20) and ARC (9) compartments, no antibacterial activity was exhibited against Clostridium tyrobutyricum and Pseudomonas aeruginosa; however, antifungal activity was observed in the feed and ARC compartments. Peptides from the ARC demonstrated activity against Mucor racemosus (MIC = 0.156 mg/mL) and showed selective antifungal effects against Penicillium commune (MIC = 0.156 mg/mL). This innovative approach paves the way for improving the recovery of anionic peptides through further optimization of the EDUF process. Future perspectives include synthesizing selected peptides and evaluating their antifungal efficacy against these and other microbial strains, offering exciting potential for applications in food preservation and beyond. Full article

One of the most important features of Metschnikowia pulcherrima is its strong antimicrobial activity against phytopathogens, which makes it a suitable candidate for use in biocontrol during crop cultivation. However, the mechanisms of its antimicrobial activity are not currently well understood. In this study, we used metabolomic methods to investigate the possible mechanisms of antimicrobial activity by M. pulcherrima against phytopathogenic fungi. First, we tested the antimicrobial activity of five selected isolates against eleven phytopathogenic molds. Based on the results, selected yeast–pathogen co-cultures were cultivated on liquid and solid media. The supernatants from the liquid co-cultures were analyzed using the UHPLC-QToF-UHRMS and MS/MS methods. Co-culture growth on solid agar media was examined using the LARAPPI/CI MSI method. The yeast exhibited strong antagonism toward the mold phytopathogens. The LARAPPI/CI MSI method revealed the presence of various compounds with potential antifungal activity. The complex UHPLC-QToF-UHRMS analysis confirmed that the metabolic response of M. pulcherrima depends on specific yeast–pathogen interactions. Full article

TasA gene, encoding a functional amyloid protein critical for biofilm formation and antimicrobial activity, was cloned from the endophytic strain Bacillus amyloliquefaciens BS-3, isolated from rubber tree roots. This study identified the shortest functional TasA variant (483 bp, 160 aa) reported to date, featuring unique amino acid substitutions in conserved domains. Bioinformatics analysis predicted a signal peptide (1–27 aa) and transmembrane domain (7–29 aa), which were truncated to optimize heterologous expression. Two prokaryotic vectors (pET28a and pCZN1) were constructed, with pCZN1-TasA expressed solubly in Escherichia coli Arctic Express at 15 °C, while pET28a-TasA formed inclusion bodies at 37 °C. Purified recombinant TasA exhibited potent antifungal activity, achieving 98.6% ± 1.09 inhibition against Colletotrichum acutatum, 64.77% ± 1.34 against Alternaria heveae. Notably, TasA completely suppressed spore germination in C. acutatum and Oidium heveae Steinmannat 60 μg/mL. Structural analysis via AlphaFold3 revealed that truncation enhanced protein stability. These findings highlight BS-3-derived TasA as a promising biocontrol agent, providing molecular insights for developing protein-based biopesticides against rubber tree pathogens. Full article

The worldwide increase in antifungal resistance, particularly in Candida sp., requires the exploration of novel therapeutic agents. Natural compounds have been a rich source of antimicrobial molecules, where peptides constitute the class of the most bioactive components. Therefore, this study looks into the target-specific binding efficacy of insect-derived antifungal peptides (n = 37) as possible alternatives to traditional antifungal treatments. Using computational methods, namely the HPEPDOCK and HDOCK platforms, molecular docking was performed to evaluate the interactions between selected key fungal targets, lanosterol 14-demethylase, or LDM (PDB ID: 5V5Z), secreted aspartic proteinase-5, or Sap-5 (PDB ID: 2QZX), N-myristoyl transferase, or NMT (PDB ID: 1NMT), and dihydrofolate reductase, or DHFR, of C. albicans. The three-dimensional peptide structure was modelled through the PEP-FOLD 3.5 tool. Further, we predicted the physicochemical properties of these peptides through the ProtParam and PEPTIDE 2.0 tools to assess their drug-likeness and potential for therapeutic applications. In silico results show that Blap-6 from Blaps rhynchopeter and Gomesin from Acanthoscurria gomesiana have the most antifungal potential against all four targeted proteins in Candida sp. Additionally, a molecular dynamics simulation study of LDM-Blap-6 was carried out at 100 nanoseconds. The overall predictions showed that both have strong binding abilities and are good candidates for drug development. In in vitro studies, Gomesin achieved complete biofilm eradication in three out of four Candida species, while Blap-6 showed moderate but consistent reduction across all species. C. tropicalis demonstrated relative resistance to complete eradication by both peptides. The present study provides evidence to support the antifungal activity of certain insect peptides, with potential to be used as alternative drugs or as a template for a new synthetic or modified peptide in pursuit of effective therapies against Candida spp. Full article

Chronic infected wounds remain a major medical challenge, particularly in the context of increasing antibiotic resistance. The objective of this study was to develop and evaluate chitosan-based (CS) sponges enhanced with graphene oxide (GO) as potential antimicrobial wound dressings. The composite sponges were fabricated using microcrystalline CS (MKCh) and 5% (w/w) GO, followed by freeze-drying and γ-sterilization (25 kGy). Physico-mechanical characterization showed that GO incorporation did not significantly alter tensile strength, while absorption and sorption capacities were improved, especially after sterilization. Structural and spectroscopic analyses confirmed increased porosity and molecular interaction between CS and GO. Cytocompatibility was verified in vitro using L-929 fibroblasts, with no cytotoxic effects observed in indirect contact. Antimicrobial activity tests demonstrated that GO-modified dressings exhibited enhanced activity against E. coli and S. aureus, though results were strain-dependent and not uniformly superior to CS alone. Notably, antifungal efficacy against C. albicans was reduced with GO addition. Overall, the developed GO-enriched CS sponges present favorable biocompatibility, mechanical resilience, and selective antimicrobial activity, supporting their potential application in chronic wound management. Further optimization of GO concentration and formulation is warranted to maximize antimicrobial efficacy across a broader spectrum of pathogens. Full article

Burkholderia gladioli is a multifaceted bacterium with both pathogenic and beneficial strains, and nonpathogenic Burkholderia species have shown potential as plant growth-promoting rhizobacteria (PGPRs) and biocontrol agents. However, the molecular mechanisms underlying their beneficial functions remain poorly characterized. This study systematically investigated the antimicrobial mechanisms and plant growth-promoting properties of B. gladioli strain ZBSF BH07, isolated from the grape rhizosphere, by combining genomic and functional analyses, including whole-genome sequencing, gene annotation, phylogenetic and comparative genomics, in vitro antifungal assays, and plant growth promotion evaluations. The results showed that ZBSF BH07 exhibited broad-spectrum antifungal activity, inhibiting 14 grape pathogens with an average inhibition rate of 56.58% and showing dual preventive/curative effects against grape white rot, while also significantly promoting grape seedling growth with increases of 54.9% in plant height, 172.9% in root fresh weight, and 231.34% in root dry weight. Genomic analysis revealed an 8.56-Mb genome (two chromosomes and one plasmid) encoding 7431 genes and 26 secondary metabolite biosynthesis clusters (predominantly nonribosomal peptide synthetases), supporting its capacity for antifungal metabolite secretion, and functional analysis confirmed genes for indole-3-acetic acid (IAA) synthesis, phosphate solubilization, and siderophore production. These results demonstrate that ZBSF BH07 suppresses pathogens via antifungal metabolites and enhances grape growth through phytohormone regulation and nutrient acquisition, providing novel insights into the dual mechanisms of B. gladioli as a biocontrol and growth-promoting agent and laying a scientific foundation for developing sustainable grapevine disease management strategies. Full article

Candida albicans is a clinically important fungal pathogen capable of causing both superficial and systemic infections, particularly in immunocompromised individuals. A key factor contributing to its pathogenicity is its ability to form biofilms, structured microbial communities that confer significant resistance to conventional antifungal therapies. Addressing this challenge, we explored the antivirulence potential of acridine derivatives, a class of heterocyclic aromatic compounds known for their diverse biological activities, including antimicrobial, antitumor, and antiparasitic properties. In this study, a series of acridine derivatives was screened against C. albicans biofilms, revealing notable inhibitory activity and highlighting their potential as scaffolds for the development of novel antifungal agents. Among the tested compounds, acridine-4-carboxylic acid demonstrated the most promising activity, significantly inhibiting the biofilm formation at 10 µg/mL without affecting planktonic cell growth, and with a minimum inhibitory concentration (MIC) of 60 µg/mL. Furthermore, it attenuated filamentation and cell aggregation in a fluconazole-resistant C. albicans strain. Toxicity assessments using Caenorhabditis elegans and plant models supported its low-toxicity profile. These findings highlight the potential of acridine-based scaffolds, particularly acridine-4-carboxylic acid, as lead structures for the development of therapeutics targeting both fungal growth and biofilm formation in Candida albicans infections. Full article

Background: Transition metal complexes incorporating fluorinated counter anions represent a significant class of compounds with broad applications in industry, pharmaceuticals, and biomedicine. These fluorinated anions are known to enhance the solubility, stability, and reactivity of the complexes, thereby expanding their functional utility in various chemical and biological contexts. Methods: A set of metal(II) complexes of the general formula [MPy₆][B(C₆F₅)₄]₂ where (Py = pyridine, M = Mn (1), Fe (2), Co (3), Ni (4), Cu (5), Zn (6)) have been synthesized by direct reaction of metal halides and pyridine in the presence of Ag[B(C₆F₅)₄]. The complexes were characterized using different techniques to assure their purity, such as elemental analysis (EA), electron paramagnetic resonance (EPR) spectroscopy, thermogravimetric analysis (TGA), ultraviolet–visible (UV–Vis) spectroscopy, ¹¹B-NMR, ¹H-NMR, and FT-IR spectroscopy. The antimicrobial and antifungal properties against different types of bacteria and fungi were studied for all prepared complexes. Results: The synthesized complexes exhibited broad-spectrum antimicrobial activity, demonstrating variable efficacy compared to the reference antibiotic, oxytetracycline (positive control). Notably, complex 6 displayed exceptional antibacterial activity against Streptococcus pyogenes, with a minimum inhibitory concentration (MIC) of 4 µg/mL, outperforming the control (MIC = 8 µg/mL). Complexes 1, 2, and 4 showed promising activity against Shigella flexneri, Klebsiella pneumoniae, and Streptococcus pyogenes, each with MIC values of 8 µg/mL. Conversely, the lowest activity (MIC = 512 µg/mL) was observed for complexes 3, 5, and 6 against Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae, respectively. Regarding antifungal properties, complexes 5 and 6 demonstrated the highest activity against Candida albicans, with MIC values of 8 µg/mL, equivalent to that of the positive control, fluconazole. Density functional theory (DFT) calculations confirmed an overall octahedral coordination geometry for all complexes, with tetragonal distortions identified in complexes 3, 4, and 5. Full article

Plants of the Annona genus have garnered increasing scientific interest due to their rich phytochemical profile and broad spectrum of biological activities, which include antimicrobial, antiproliferative, and cytotoxic effects. Among the most studied compounds are acetogenins and Annonacins, which exhibit potent bioactivity and have been identified as key agents in the green synthesis and stabilization of nanomaterials. In recent years, the integration of Annona plant extracts—particularly from leaves—into nanotechnology platforms has opened new avenues in the development of eco-friendly and biocompatible nanostructures for biomedical applications. This review provides a comprehensive overview of the current knowledge regarding the antimicrobial properties of nanomaterials synthesized using extracts from Annona species. This review encompasses 74 indexed articles published between 2012 and 2023, focusing on the synthesis of nanomaterials using extracts from this genus that exhibit antimicrobial and biomedical properties. The search was conducted in databases such as Google Scholar, Web of Science, and Scopus. Emphasis is placed on their antibacterial, antifungal, and anthelmintic effects, as well as additional therapeutic potentials, such as antidiabetic, antihypertensive, antiproliferative, and cytotoxic activities. The analysis of the recent literature highlights how Annona-derived phytochemicals contribute significantly to the functionalization and enhanced biological performance of these nanomaterials. This work aims to support future research focused on the rational design of Annona-based nanostructures as promising candidates in antimicrobial and therapeutic strategies. Full article

Malva sylvestris L. is a herbaceous plant, distributed worldwide, rich in biological active compounds, and known for its health benefits. In this study, extracts from different parts (leaves, flowers, and roots) of this plant were prepared using green classic (70% ethanol) and natural deep eutectic solvents (NADESs) based on choline chloride and acetic acid (NADES1) or glycerol (NADES2). Their antioxidant, antibacterial (against B. cereus, S, aureus, E. coli, and P. aeruginosa), and antifungal activity (against P. chrysogenum, F. oxysporum, A. parasiticus, A. flavus, A. niger A. carbonarius, and A. ochraceus) were compared. Ethanolic extracts were characterized with the highest total contents of phenols, flavonoids, and condensed tannins. Ethanolic and NADES flower extracts were the richest in the antioxidants tested. Alkaloids were extracted in low quantities. The experimentally determined antioxidant potential of the extracts proved the highest DPPH scavenging activity of ethanolic extracts and the lowest of NADES1 extracts. The ABTS scavenging capacity of NADES1 and ethanolic extracts displayed comparable results, while NADES2 extracts were characterized as having the highest FRAP activity. NADES1 extracts manifested pronounced antibacterial activity, partially due to the low pH of the pure solvent, as well as inconsistent antifungal activity—from moderate to a complete lack of activity. A strong positive correlation was reported between the DPPH radical scavenging capacity and phenolic compound content. Future detailed investigations on the mechanism of the antimicrobial activity of NADES1 extracts are necessary to clarify the observed phenomenon of the decreased antifungal potential of NADES1 extracts compared to the pure solvent NADES1. Full article

Background/Objectives: There is an increasing incidence of fungal infections in conjunction with the rise in resistance to medical treatment. Antimicrobial resistance is frequently associated with virulence factors such as adherence and the capacity of biofilm formation, which facilitates the evasion of the host immune response and resistance to drug action. Novel therapeutic strategies have been developed to overcome antimicrobial resistance, including the use of different type of nanomaterials: metallic (Au, Ag, Fe₃O₄ and ZnO), organic (e.g., chitosan, liposomes and lactic acid) or carbon-based (e.g., quantum dots, nanotubes and graphene) materials. The objective of this study was to evaluate the action of nanoparticles of different synthesis and with different coatings on fungi of medical interest. Methods: Literature research was conducted using PubMed and Google Scholar databases, and the following terms were employed in articles published up to June 2025: ‘nanoparticles’ in combination with ‘fungal biofilm’, ‘Candida biofilm’, ‘Aspergillus biofilm’, ‘Cryptococcus biofilm’, ‘Fusarium biofilm’ and ‘dermatophytes biofilm’. Results: The utilization of nanoparticles was found to exert a substantial impact on the reduction in fungal biofilm, despite the presence of substantial variability in minimum inhibitory concentration (MIC) values attributable to variations in nanoparticle type and the presence of capping agents. It was observed that the MIC values were lower for metallic nanoparticles, particularly silver, and for those synthesized with polylactic acid compared to the others. Conclusions: Despite the limited availability of data concerning the stability and biocompatibility of nanoparticles employed in the treatment of fungal biofilms, it can be posited that these results constitute a significant initial step. Full article

This study focuses on the search for new effective synthetic antimicrobial compounds as a tool against the widespread presence of microorganisms resistant to existing drugs. Five derivatives of [1,3]thiazolo[3,2-b][1,2,4]triazoles were synthesized using an accessible protocol based on electrophilic heterocyclization and were characterized using infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopies, and their in vitro antimicrobial and antifungal activities were evaluated using the agar plate diffusion method and the microdilution plate procedure. Both antibacterial (Gram-positive and Gram-negative) and antifungal activities were found for the examined samples. The minimum inhibitory concentration (MIC) varied from 0.97 to 250 µg/mL, and the minimum bactericidal concentration (MBC) from 1.95 to 500 µg/mL. Compound 2a showed good antifungal action against Candida albicans and Saccharomyces cerevisiae with minimum fungicidal concentration (MFC) 125 and MIC 31.25 µg/mL. The molecular docking revealed that the 2-heptyl-3-phenyl-6,6-trimethyl-5,6-dihydro-3H-[1,3]thiazolo[3,2-b][1,2,4]triazol-7-ium cation stands out as a highly promising candidate for further investigation due to a wide range of interactions, including conventional hydrogen bonds, π–σ, π–π T-shaped, and hydrophobic alkyl interactions. The synthesis and preliminary evaluation of [1,3]thiazolo[3,2-b][1,2,4]triazoles yielded promising antimicrobial and antifungal candidates. The diverse interaction profile of the 2-heptyl derivative salt allows this compound’s selection for further biological studies. Full article

To date, various species of Erigeron genus have been used both in the ethnopharmacology of numerous nations across the world and in contemporary herbal practices. The objective of this study is to revise the phytochemical data on the essential oils (EOs) of various fleabanes species and to evaluate the variability of their biological activities. Up to June 2025, this review provides an updated overview of 105 literature sources (published during last 25 years) related to 14 Erigeron sp. (native, naturalized, or invasive) which have been investigated extensively and are of the greatest significance. It summarizes the compositional variability of the EOs and their pharmacological and toxic effects, such as anti-inflammatory, anticancer, antiproliferative, skin regeneration, antioxidant, antifungal, antibacterial, insecticidal, larvicidal, repellent, and allelopathic activity. The EOs of each Erigeron species were characterized, and a chemical structure of 43 major constituents is presented herein. The most characteristic and prevalent compounds were found to be limonene, δ-3-carene, matricaria ester, lachnophyllum ester, germacrene D, β-caryophyllene, β-farnesene, α-bergamotene, allo-aromadendrene, etc., in the EOs from the E. acris, E. annuus, E. bonariensis, E. canadensis, E. floribundus E. mucronatus, and E. speciosus plants. Major constituents, such as borneol, bornyl acetate, modhephen-8-β-ol, cis-arteannuic alcohol, β-caryophyllene, and τ-cadinol, were found in the oils of E. graveolens (Inula graveolens). A paucity of data concerning E. incanus EOs was revealed, with the prevalence of 3-hydroxy-4-methoxy cinammic acid and thymol acetate noted in the oils. The EOs from E. multiradiatus and E. sublyratus were comprised mainly of matricaria and lachnophyllum esters. The available data on EOs of E. ramosus is limited, but the main constituents are known to be α-humulene, 1,8-cineole, eugenol, and globulol. The EOs containing appreciable amounts of matricaria and lachnophyllum esters exhibited strong anticancer, anti-inflammatory, antimicrobial, larvicidal, and repellent activities. Repellence is also related to borneol, bornyl acetate, caryophyllene derivatives, τ-cadinol, modhephen-8-β-ol, and cis-arteannuic alcohol. Cytotoxicity was determined due to the presence of limonene, δ-3-carene, α- and β-farnesene, (E)-β-ocimene, ledene oxide, sesquiphellandrene, and dendrolasin in the fleabanes EOs. Skin regeneration and antifungal properties were related to germacrene D; and anti-inflammatory effects were determined due to high amounts of limonene (E)-β-ocimene, lachnophyllum ester, and germacrene D. The antimicrobial properties of the oils were conditioned by appreciable quantities of limonene, β-pinene, 1,8-cineole, carvacrol, thymol acetae, β-eudesmol, 2,6,7,7α-tetrahydro-1,5-dimethyl-1H-indene-3-carboxaldehyde, caryophyllene and its oxide, allo-aromadendrene, α-humulene, farnesene, carvacrol, and eugenol. This review provides a foundation for further studies on volatile secondary metabolites to explore the potential sources of new biologically active compounds in Erigeron sp. Full article