Search Results (494)

This research provides a comprehensive evaluation of the phytochemical composition, antioxidant potential, and biological properties of four plant species with longstanding use in ethnobotanical traditions: Calendula officinalis, Mentha × piperita, Urtica dioica, and Juglans regia. Plant extracts were obtained using a range of solvent systems and subsequently analyzed for their content of total polyphenols, flavonoids, and phenolic acids. Ultra-high-performance liquid chromatography coupled with mass spectrometry (UHPLC-MS) enabled the accurate identification and quantification of major polyphenolic constituents. The antioxidant capacity was assessed through a series of in vitro assays, and elemental analysis was conducted to determine microelement content. To evaluate potential ecological implications, acute toxicity was tested using Daphnia magna, while phytotoxic effects were also examined. The results demonstrate pronounced antioxidant activity along with notable biocidal and soil-enhancing properties. These findings underscore the potential of such plant-based formulations as sustainable alternatives to conventional agrochemicals and highlight the relevance of integrating traditional botanical knowledge with modern strategies for enhancing soil quality, crop performance, and environmental sustainability. Full article

Common lilac (Syringa vulgaris) is an important cut flower on the flower market. The process of forcing shrub is crucial for lilac availability for floristry for six months of the year: from November to April. In this study, the vase life and certain biochemical processes occurring during senescence of cut lilacs ‘Andenken an Ludwig Spaeth’ induced to flower between March and May were investigated. Additionally, the effect of standard preservative (8-HQC + 2% S) and biocide (8-HQC) was analyzed. The vase life in water was relatively short (4 d), although it lengthened with the season and the standard preservative improved it. This solution enhanced florets’ fresh weight, water uptake, and transpiration rate, also caused an increase in the electroconductivity of the cell sap. Several other senescence-associated parameters such as carbohydrate, soluble protein and free proline contents were affected by the preservative whose effects were comparable to those found earlier in the winter forced lilacs. A highly efficient antioxidant enzyme system including catalase (CAT), peroxidases (POX) and superoxide dismutase (SOD) was present in developing inflorescences but the enzyme activity decreased in senescing florets. The hydrogen peroxide content and catalase activity were the highest in the biocide-treated flowers. Generally, in cut lilacs induced to bloom in April the changes in senescence-associated phenomena under study were occurring as in the flowers forced for November–December sales. Research shows the significant importance of sugar as a component of the cut flower preservatives whose use was essential for a proper bud development and good postharvest quality of cut lilacs. Full article

The conservation of cultural heritage has long garnered significant attention within the scientific community, particularly due to the biodeterioration processes driven by microbial colonization. These processes can severely compromise the aesthetic, chemical, and physical integrity of artworks. While traditional chemical biocides are widely used, they present notable drawbacks, including toxicity, chemical instability, and the risk of inducing microbial resistance. Accordingly, efforts to expand the repertoire of molecules with biocidal activity are of utmost significance. In this study, we report the synthesis and characterization of selenium-based biocides with biocidal activity. Characterization was performed using NMR spectroscopy and gas chromatography–mass spectrometry (GC-MS). The biocidal efficacy of these compounds was evaluated via algal growth inhibition tests (OECD 201), employing Raphidocelis subcapitata as a model organism. Our results indicate that certain seleno-sugars exhibit a dose-dependent inhibition of algal growth, suggesting superior biocidal activity compared to conventional agents. Notably, one compound demonstrated an optimal balance of efficacy and chemical stability and was selected for subsequent in vivo testing. Full article

Biofumigation was originally proposed as an alternative to toxic fumigants for the treatment of agricultural soils, owing to the biocidal effect of isothiocyanates (ITCs) released by some plant species like Brassicaceae. However, biofumigation also presents limitations; thus, an advanced and viable alternative could be the use of controlled-release systems such as gelled polymer networks. In the present work, we explore the use of biocompatible hydrogels based on sodium alginate (ALG) and sodium carboxymethylcellulose (CMC), conveniently loaded with a Brassicaceae extract for this purpose. The extract was characterized by means of HPLC-MS, showing its high glucosinolate content, especially glucoraphanin, a secondary metabolite produced by several species of this family. The physicochemical properties of the synthesized gels were investigated by means of differential scanning calorimetry (DSC), rheometry, and scanning electron microscopy (SEM), both in the presence and absence of the loaded extract. Loading and release kinetics (in water) were studied by means of HPLC-DAD, and the Weibull model was employed to interpret the results. It was found that both hydrogels can effectively confine the Brassicaceae extract’s active principle, slowly releasing it in an aqueous environment. Both systems possess excellent properties for real applications, with the CMC-based hydrogels being slightly preferable over the ALG ones due to their higher encapsulation efficiency, mechanical properties, and overall features. These systems are promising tools for combating harmful microorganisms due to the biocidal properties of glucosinolates, but their potential goes beyond their use in agriculture, as they could be applied as antifouling or antimicrobial agents in cultural heritage cleaning or other fields. Full article

The COVID-19 pandemic has inflicted unprecedented pressure on communities and healthcare systems around the world. An outstandingly broad and intensive investigation of possible therapeutic interventions is currently taking place to prevent similar future threats to the global population. Investigating the related mechanisms of action is often complex and time consuming. Moreover, research on biochemical interactions of new drugs involves a considerable amount of effort, consequently bearing inherent financial and operational risks for pharmaceutical companies. An interesting approach to counteract colonization and infection is the concept of antiseptic treatment in vivo. Antiseptics are cost-effective and globally accessible, due to their ease of production, transportation and handling. A broad spectrum of active agents with different properties is readily available. One of these substances is hypochlorous acid (HOCl), which is also a naturally occurring biocidal agent and as such part of the innate immune system. Its successful history of medical use in wound treatment, combined with low cytotoxicity and documented efficacy against various pathogens, suggests that HOCl might be an effective agent for treating the respiratory mucosa. This could potentially enable therapeutic inhalation for combating bacterial infections and viral pathogens such as human respiratory syncytial, influenza, and SARS-CoV-2 viruses, which will be discussed in the present article. Full article

Due to the growing emergence of bacterial and fungal resistance, there is an urgent need for novel antimicrobial compounds. Cationic surfactants are effective antimicrobial agents; however, traditional quaternary ammonium compounds (QACs) are increasingly scrutinized due to their cytotoxicity, poor biodegradability, and harmful effects on aquatic ecosystems. While the antimicrobial efficacy of many new biocides, including QACs, has been extensively studied, comprehensive experimental strategies that simultaneously assess antimicrobial activity, mammalian cell toxicity, and ecotoxicity remain limited. Recent studies have reported that amino-acid-based surfactants containing arginine-phenylalanine and arginine-tryptophan exhibit excellent antibacterial activity and are biodegradable. This work extends their biological characterization to evaluate their potential applications. Specifically, we examined how variations in the head group architecture and hydrophobic moiety influence antifungal and antibiofilm activity. We also assessed how these structural parameters impact cytotoxicity and ecotoxicity. These compounds demonstrated strong activity against a wide range of Candida strains. Their hydrophobic character primarily influenced both antifungal efficacy and cytotoxicity. Importantly, these surfactants exhibited potent antimicrobial and antibiofilm effects at non-cytotoxic concentrations. Notably, their aquatic toxicity was significantly lower than that of conventional QACs. Full article

Background: Trichosporon spp. are opportunistic fungi, capable of causing infection, especially in critically ill individuals who often use broad-spectrum antibiotics, invasive devices, and have comorbidities. Objectives The aim of this study was to analyze individuals’ clinical characteristics, evaluate tolerance to biocides, as well as biofilm formation and efflux pump activity in isolates of Trichosporon asahii. Methods: Clinical isolates of T. asahii collected between 2020 and 2023 from both hospitalized and non-hospitalized individuals, of both sexes, regardless of age, were tested for tolerance to sodium hypochlorite, hydrogen peroxide, benzalkonium chloride, and ethyl alcohol. Efflux pump activity was also assessed using ethidium bromide, and biofilm formation was measured with the Safranin test. Clinical parameters such as outcomes, source, and length of hospitalization were analyzed through electronic medical records. Results: A total of 37 clinical isolates of T. asahii were identified. Thirty-three (83.8%) isolates were from hospitalized individuals, with 81.82% collected in ICUs, an average hospital stay of 35 days, and a mortality rate of 51.6%. The tested strains displayed the largest mean inhibition zone for 2% sodium hypochlorite, indicating lower tolerance. A high level of efflux pump expression was detected among clinical isolates. Biofilm formation was detected in 25/67.5% of the isolates. Conclusions: These findings highlight the clinical relevance of T. asahii, particularly in critically ill individuals, and underscore the pathogen’s ability to tolerate biocides, express efflux pumps, and form biofilms, all of which may contribute to its persistence and pathogenicity in hospital environments. Enhanced surveillance and effective microbial control measures are essential to mitigate the risks associated with T. asahii infections. Full article

The prevention of biofilm formation and algal biodeterioration on building materials, particularly on cultural heritage sites, is a growing concern. Due to regulatory restrictions on conventional algicidal biocides in Europe, natural alternatives such as essential oils are gaining interest for their potential use in heritage conservation. This study evaluates the anti-algal activity of Salvia officinalis and Equisetum arvense (essential oils, hydrolates, and extracts) against a mixed culture of five green algae species (Bracteacoccus minor, Stichococcus bacillaris, Klebsormidium nitens, Chloroidium saccharophilum, and Diplosphaera chodatii). The plant materials were processed using hydrodistillation and solvent extraction, followed by chemical characterization through gas chromatography–mass spectrometry (GC-MS). Biological efficacy was assessed by measuring algal growth inhibition, changes in biomass colour, chlorophyll a concentration, and fluorescence. S. officinalis yielded higher extract quantities (extraction yield: 23%) than E. arvense and contained bioactive compounds such as thujone, camphor, and cineole, which correlated with its strong anti-algal effects. The essential oil of S. officinalis demonstrated the highest efficacy, significantly inhibiting biofilm formation (zones of inhibition: 15–94 mm) and photosynthetic activity at 0.5% concentration (reduction in chlorophyll a concentration 90–100%), without causing visible discolouration of treated surfaces (∆E < 2). These findings highlight the potential of S. officinalis essential oil as a natural, effective, and material-safe algicidal biocide for the sustainable protection of cultural heritage sites. Full article

Photodynamic inactivation (aPDI) involves the interaction of three components: non-toxic photosensitizer molecules (PS), low-intensity visible light, and molecular oxygen. This interaction leads to the generation of toxic reactive oxygen species. The present work demonstrated the efficacy of light-induced antimicrobial photodynamic inactivation against Pseudomonas aeruginosa and Pseudomonas putida using 5-aminolevulinic acid (5-ALA) as a prodrug to produce the photosensitizer protoporphyrin IX. The photoeradication efficiency of these pathogens under blue (405 nm; 45 mW cm⁻²) and red (635 nm; 53 mW cm⁻²) light was investigated. Results showed that at least 30 min of blue light irradiation was necessary to achieve a 99.999% reduction of P. aeruginosa, whereas red light was less effective. P. putida exhibited limited susceptibility under similar conditions. To enhance aPDI efficiency, exogenous glucose was added alongside 5-ALA, which significantly increased the photodynamic efficacy—particularly against P. aeruginosa—leading to complete eradication after just 5 min of exposure. Spectroscopic analyses confirmed that glucose increased the levels of protoporphyrin IX, which correlated with enhanced photodynamic efficacy. Furthermore, multiple aPDI exposure reduced key virulence factors, including alkaline protease activity, biofilm formation, and swarming motility (in P. aeruginosa). These findings suggest that 5-ALA-mediated photodynamic inactivation offers a promising strategy to improve efficacy against resistant Gram-negative pathogens. Full article

Polymers containing biocidal moieties (e.g., amino or ammonium groups) are considered promising materials that can help combat the growing resistance of pathogens to commonly used antimicrobials. Searching for new polymeric biocides, in this work, non-porous and porous poly(hydromethylsiloxane) (PHMS) networks were prepared and post-functionalized by N-allylaniline (Naa). Non-porous networks were obtained by cross-linking PHMS in the bulk and porous—in W/O high-internal-phase emulsion (HIPE). Linear divinyldisiloxane (M₂^Vi) or cyclic tetravinyltetrasiloxane (D₄^Vi) were used as cross-linkers. Studies confirmed the expected non-porous and open macroporous microstructure of the initial networks. They also showed that functionalization by Naa was more efficient for the non-porous networks that swelled to lower extents in toluene and contained higher amounts of Si-H groups than the porous ones. In the reactions with benzyl chloride or 1-bromoctane, some amino groups present in these materials were transformed to ammonium groups. It was found that activity against Gram-positive S. aureus and Gram-negative E. coli bacteria depended on the functionalization degree, cross-linking level and the microstructure of the modified materials. Full article

Microorganisms take an active part in the processes of microbiologically influenced corrosion, which is protected against by using bactericides—often toxic compounds—with inhibitory properties. There are many studies of eco-friendly “green” biocides/inhibitors, in particular those based on microbial metabolites. Indicators for the processes of microbial corrosion of steel 3 induced by the sulfate-reducing bacteria Desulfovibrio oryzae NUChC SRB2 under the influence of the strains Bacillus velezensis NUChC C2b and Streptomyces gardneri ChNPU F3 have not been investigated, which was the aim of this study. The agar well diffusion method (to determine the antibacterial properties of the supernatants) was used, along with the crystal violet (to determine the biomass of the biofilm on the steel) and gravimetric methods (to determine the corrosion rate). A moderate adhesiveness to steel 3 was established for D. oryzae due to its biofilm-forming ability. The presence of a supernatant on cultures of S. gardneri, B. velezensis and their mixture (2:1) did not reduce the biofilm-forming properties of D. oryzae. Compared to the control, a decrease in the corrosion rate was recorded for the variant of the mixture of the studied bacterial culture supernatants. This indicates the potential of this mixture for use in corrosion protection in environments with sulfate-reducing bacteria, which requires further research. Full article

Cationic surfactants, accounting for approximately 7% of the global surfactant market, are widely used in applications such as fabric softeners, biocides, and corrosion inhibitors. Recently, gemini surfactants—comprising two amphiphilic units linked by a spacer—have attracted significant interest due to their superior surface activity, lower critical micelle concentrations, and strong antimicrobial properties. However, their poor biodegradability, resulting from their complex molecular structure, has raised environmental concerns. To address this, researchers have developed ester-based gemini surfactants incorporating biodegradable bonds. This study aimed to investigate the relationship between the structure of ester-based gemini surfactants (hydrophobic chain length and spacer type) and their antimicrobial activity against bacteria and fungi. Three series of compounds featuring different functional groups in the spacer were synthesized, along with a trimeric surfactant for comparative purposes. The results demonstrated that both the hydrophobic chain length and the presence of additional cationic groups significantly influence the CMC and antimicrobial performance. Quantum mechanical calculations were also performed to search for correlations between electronic properties and chemical reactivity of compounds. These findings highlight that ester-based gemini surfactants combine high surface and antimicrobial activity with the potential for improved biodegradability, making them promising candidates for use in environmentally friendly applications. Full article

The prevention of biofouling (biological fouling) became a major economic and environmental issue. In the present study, we designed a series of four cyclam and cyclen derivatives with a modulation of their lipophilicity by introducing either two benzyl (Bn) groups or two tetradecyl (C₁₄) chains in the structure to produce (Cyclam(Bn)₂, Cyclam(C₁₄)₂, Cyclen(Bn)₂ and Cyclen(C₁₄)₂). Additionally, copper (Cu) and zinc (Zn) complexes of each compound were prepared and evaluated as potential antifouling candidates against two models of Vibrio species (V. natriegens and V. aestuarianus). The results highlight that no significant antifouling activity was measured for the metal free polyazamacrocyclic derivatives. However, for the metal complexes, the nature of the cation (Cu²⁺ or Zn²⁺) modulates both the growth and adhesion capacities of the two bacteria. Overall, in most cases, Zn complexes showed better activity than the Cu complexes, revealing the importance of the metal cation. Moreover, in the cyclam series, the anti-adhesion properties could be linked to a biocidal effect while a full anti-adhesion activity was observed in the cyclen series. Full article

This study tested the effectiveness of a bifunctional polysiloxane (L43) as a means of protecting concrete surfaces from biocorrosion. L43 was designed to contain two types of functional groups in its structure: surface-active hydrophobic chains and hydrophilic groups that allow the coating to permanently bond to the concrete. L43-coated cement samples achieved compressive strengths exceeding 70 MPa, while samples subjected to cyclic freeze–thaw tests achieved compressive strengths exceeding 33 MPa. In addition, compound L43 at a concentration of 5% reduced the photosynthetic activity of microalgae cells on the concrete surface. The maximum value of chlFI decreased by 69.5%, while the average value decreased by 71.4%. Thus, it was proven that compound L43 effectively counteracts biological corrosion without deteriorating the structure of the impregnated substrate. It should be emphasized that the biocidal effect is due to the structure of the siloxane compound and appropriately selected functional groups. There is no need to add harmful biocides, making the solution environmentally friendly. In addition, the coating allows for free air circulation, which is crucial for the protection of building and construction materials. Full article

The only biocidal iodine species in topical iodine disinfectants is molecular iodine (I2). I2, a biomolecule, has broad-spectrum antimicrobial activity and does not generate resistance. Physicians, regulatory agencies, and scientists have assumed that I2 is responsible for the skin staining and irritation associated with the clinical use of iodine disinfectants; this assumption is deeply embedded in the medical community but is not supported with empirical data. This study provides the first experimental data that measure the biocompatibility of I2 with human skin. Human skin explants in tissue culture were evaluated at 3, 7, and 24 h after being exposed to I2 (500 to 15,000 ppm). Cell viability was measured relative to phosphate-buffered saline using 3-[4,5-dimethylthiazol-2yl]-2,5-diphenyl-tetrazolium bromide (MTT). The biocidal activity of I2 vapor emitted from silicone was demonstrated against bacteria growing on agar to confirm I2 off-gassing from skin was an active biocide. Additionally, statistically significant bacterial reductions with both gas and solution phase I2 were observed in a static and dynamic five-species wound biofilm. The data suggest that high, e.g., 50–5000 ppm, levels of I2 should be incorporated into topical iodine disinfectants instead of the very low (0.2–10 ppm) levels found in 10% povidone iodine products currently in use. Full article