Search Results (2,088)

A new copper(II) complex was synthesized using chromone-2-carboxylic acid as the main ligand, and coordinated pyridine molecules. The complex was successfully crystallized and structurally characterized by single crystal X-ray diffraction. This revealed a mononuclear structure with a distorted square pyramidal geometry around the central Cu(II) ion. The coordination sphere comprises oxygen atoms from the chromone moiety and nitrogen atoms from pyridine, resulting in a five-coordinate complex. A comprehensive physicochemical characterization was performed using Fourier transform infrared spectroscopy (FT-IR), UV–Vis spectroscopy, elemental (C, H, N), electrochemical (CV) and thermal analysis (TGA/DSC) to confirm the coordination environment and thermal stability of the compound. The complex exhibits distinct spectroscopic features indicative of ligand–metal charge transfer and d–d transitions typical of Cu(II) species. In addition, the synthesized complex was subjected to antimicrobial screening against Gram-positive and Gram-negative bacteria. The compound showed promising antibacterial activity, particularly against Escherichia coli, indicating its potential as a bioactive coordination compound. These results contribute to the growing body of research on metal-based chromone derivatives and emphasize the importance of copper complexes for the development of new antibacterial agents with defined crystal structures. Full article

Plant-based extracts and elicitors (signaling molecules that activate the fruit’s innate defense responses) have emerged as promising and sustainable alternatives to synthetic chemicals for preserving postharvest fruit quality and extending shelf life. This review provides a comprehensive analysis, uniquely complemented by a bibliometric assessment of the research landscape from 2005 to 2025, to identify key trends and effective solutions. This review systematically examined the efficacy of various natural compounds including essential oils (complex volatile compounds with potent antimicrobial activity such as lemongrass and thyme), phenolic-rich botanical extracts like neem and aloe vera, and plant-derived elicitors such as methyl jasmonate and salicylic acid. Their preservative mechanisms are multifaceted, involving direct antimicrobial activity by disrupting microbial membranes, potent antioxidant effects that scavenge free radicals, and the induction of a fruit’s innate defense systems, enhancing the activity of enzymes like superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD). Applications of edible coatings of chitosan or aloe vera gel, nano-emulsions, and pre- or postharvest treatments effectively reduce decay by Botrytis cinerea and Penicillium spp.), delay ripening by suppressing ethylene production, minimize water loss, and alleviate chilling injury. Despite their potential, challenges such as sensory changes, batch-to-batch variability, regulatory hurdles, and scaling production costs limit widespread commercialization. Future prospects hinge on innovative technologies like nano-encapsulation to improve stability and mask flavors, hurdle technology combining treatments synergistically, and optimizing elicitor application protocols. This review demonstrates the potential of continued research and advanced formulation to create plant-based preservatives, that can become integral components of an eco-friendly postharvest management strategy, effectively reducing losses and meeting consumer demands for safe, high-quality fruit. Full article

Animal venoms are rich in bioactive molecules with promising biotechnological potential. They comprise both protein and non-protein toxins. Among the protein toxins are enzymes, such as phospholipases A₂, proteases and L-amino acid oxidases (LAAOs). LAAOs exhibit antimicrobial, antiparasitic, antiviral, and anticancer effects, making them potential candidates for biotechnological applications. These activities are linked to their ability to catalyze oxidative reactions that convert L-amino acids into α-keto acids, releasing ammonia and hydrogen peroxide, which contribute to the immune response, pathogen elimination, and oxidative stress. However, in snakes of the Micrurus genus, LAAOs generally represent a small portion of the venom (up to ~7%), which limits their isolation and study. To overcome this, the present study aimed to produce Ml-LAAO, the enzyme from Micrurus lemniscatus, through heterologous expression in mammalian cells. The gene sequence was inferred from its primary structure and synthesized into the pSecTag2B vector for expression in HEK293T cells. After purification using a His Trap-HP column, the presence of recombinant Ml-LAAO (Ml-LAAOrec) was confirmed by Western blot and mass spectrometry, validating its identity. These results support successful recombinant expression of Ml-LAAO and highlight its potential for scalable production and future biotechnological applications. Full article

Antimicrobial peptides (AMPs), also referred to as host defense peptides, are promising molecules in the development of the next generation of antibiotics against drug-resistant bacterial pathogens. Thanatin comprises a family of naturally occurring cationic AMPs derived from several species of insects. The first thanatin, 21 residues long, was identified from the spined soldier bug, and more thanatin peptides have been discovered in recent studies. The 16-residue thanatin from Anasa tristis, or Ana-thanatin, represents the shortest sequence in the family. However, the antimicrobial activity and mechanistic process underpinning bacterial cell killing have yet to be reported for Ana-thanatin peptide. In this work, we examined the antibacterial activity, structures, and target interactions of Ana-thanatin. Our results demonstrated that Ana-thanatin exerts potent antibiotic activity against strains of Gram-negative and Gram-positive bacteria. Biophysical studies demonstrated that Ana-thanatin interacts with LPS outer membrane and can permeabilize the OM barrier in the process. Atomic-resolution structures of the peptide in free solution and in complex with lipopolysaccharide (LPS) micelle were solved by NMR, determining canonical β-sheet structures. Notably, in complex with LPS, the β-sheet structure of the peptide was better defined in terms of the packing of amino acid residues. Further, MD simulations demonstrated rapid binding of the Ana-thanatin peptide with the LPS molecules within the lipid bilayers. These studies have revealed structural features which could be responsible for LPS-OM disruption of the Gram-negative bacteria. In addition, NMR heteronuclear single quantum coherence (HSQC) studies have demonstrated that Ana-thanatin can strongly interact with the LPS transport periplasmic protein LptA_m, potentially inhibiting OM biogenesis. Taken together, we surmise that the Ana-thanatin peptide could serve as a template for the further development of novel antibiotics. Full article

The growing ineffectiveness of common antibiotics against multidrug-resistant pathogens has made antimicrobial resistance (AMR) a serious global health concern. This review emphasizes that natural antibiotics from animals, bacteria, fungi, and plants are worthy alternatives for combating this crisis. Evolutionary pressure has shaped these molecules, leading to antibiotic-resistant bacteria that can withstand single-target synthetic drugs but are vulnerable to multiple attack pathways (e.g., cell wall disruption, protein synthesis inhibition, biofilm interference) from natural compounds. Natural antibiotics are frequently incorporated into treatment strategies or drug-delivery systems for minimizing side effects, reducing doses, and improving their effectiveness. The review discusses recent progress in this field, describing the mechanisms of action of natural antibiotics, their incorporation into several drug-delivery systems, and their ‘omics’-driven discovery to improve production, while expressing the challenges that remain. Extracellular application of these compounds, however, is compromised by their low stability in the extracellular environment; furthermore, formulation advancements, such as nanoparticle encapsulation, have been shown to enhance the bioavailability and activity of these substances. Combining indigenous knowledge and modern scientific advances, natural antibiotics may be developed to fight AMR both as monotherapy and adjuvants in a sustainable way. Leveraging these synergies, alongside the latest advances in research, is key to bridging the antibiotic discovery–resistance gap and may provide a route to clinical translation and global AMR control. The promise of natural antibiotics is clear, but their path to mainstream medicine is fraught with obstacles like reproducibility, standardization, and scalability. It is more realistic to see these substances as powerful complements to existing therapies, not outright replacements. Their true strength is in their ability to interfere with resistance mechanisms and create new possibilities for drug development, positioning them as a vital, though complicated, part of the global effort to combat AMR. Full article

Artemisia herba-alba Asso. is a medicinal plant rich in phenolic compounds with strong antioxidant and antimicrobial activities. However, these bioactive molecules are highly sensitive to environmental conditions, limiting their stability and potential applications. This study investigated, for the first time, the encapsulation of ethanolic extracts from the aerial parts of A. herba-alba by spray-drying, using maltodextrin (MD) and sodium caseinate (SC) as wall materials. The extract was obtained by ultrasound-assisted extraction, and both free and encapsulated forms were analyzed for phytochemical composition, antioxidant capacity, and antibacterial activity. Spray-dried microcapsules (SDE) were further characterized for encapsulation yield, efficiency, moisture, water activity, hygroscopicity, particle size, and structural integrity (SEM, ATR-FTIR, TGA/DTG). The process resulted in a high encapsulation yield (69.40%) and efficiency (96.39%), producing microcapsules with a small average size (10.05 ± 0.08 µm), low moisture (4.34%), low water activity (0.415), and moderate hygroscopicity (12.67%). Although the encapsulated extract showed lower total phenolic content, antioxidant capacity, and antibacterial activity compared to the free extract, SEM observations confirmed the formation of spherical, crack-free microcapsules, ATR-FTIR analysis revealed non-covalent interactions between wall materials and phenolics, and TGA/DTG demonstrated improved thermal stability. These results highlight spray-drying microencapsulation as an efficient approach to stabilize A. herba-alba phenolic compounds, offering promising applications as natural preservatives in the food industry. Full article

Tuberculosis (TB), caused by Mycobacterium tuberculosis (MTB), remains one of the most devastating infectious diseases worldwide, with rising multidrug resistance limiting the effectiveness of conventional treatments. Novel therapeutic approaches are urgently needed to complement or replace existing regimens. Among emerging candidates, antimicrobial peptides (AMPs) stand out as versatile molecules capable of exerting direct antimycobacterial effects while also modulating the host immune response. This review explores peptide-based strategies against TB, with a focus on four major axes of innovation. First, we examine host-directed pathways, including the vitamin D–cathelicidin axis and other immunomodulatory mechanisms and their regulatory role in the induction of endogenous AMPs such as cathelicidin LL-37, which contributes to host-directed defense. Second, we discuss peptide-based vaccines designed to elicit robust and durable protective immunity, representing a complementary alternative to classical vaccine approaches. Third, we highlight the synergistic potential of AMPs in combination with first-line and second-line anti-TB drugs, aiming to restore or enhance bactericidal activity against resistant strains. Finally, we analyze technological platforms, including nanocarriers and inhalable formulations, that enable targeted pulmonary delivery, improve peptide stability, and enhance bioavailability. By integrating molecular design, immune modulation, and advanced delivery systems, peptide-based strategies provide a multifaceted approach to overcoming the limitations of current TB therapy. Collectively, these advances position AMPs not only as promising standalone agents but also as key components in combination and host-directed therapies, with strong potential to reshape the future clinical management of tuberculosis. Full article

Hydrogels have emerged as promising biomaterials for oral tissue regeneration thanks to their high-water content, excellent biocompatibility, and ability to mimic native tissue environments. These versatile materials can be tailored to support cell adhesion, proliferation, and differentiation, making them suitable for repairing both soft and hard oral tissues. When engineered from natural polymers and enriched with bioactive agents, hydrogels offer enhanced regenerative potential. Biopolymer-based hydrogels, derived from materials such as chitosan, alginate, collagen, hyaluronic acid, and gelatin, are particularly attractive due to their biodegradability, bioactivity, and structural similarity to the extracellular matrix, creating an optimal microenvironment for cell growth and tissue remodeling. Recent innovations have transformed these systems into multifunctional platforms capable of supporting targeted regeneration of periodontal tissues, alveolar bone, oral mucosa, dental pulp, and dentin. Integration of bioactive molecules, particularly essential oils, bio-derived constituents, cells, or growth factors, has introduced intrinsic antimicrobial, anti-inflammatory, and antioxidant functionalities, addressing the dual challenge of promoting tissue regeneration while at the same time attenuating microbial contamination in the oral environment. This review explores the design strategies, material selection, functional properties, and biomedical applications in periodontal therapy, guided tissue regeneration, and implant integration of natural polymer-based hydrogels enriched with bioactive factors, highlighting their role in promoting oral tissue regeneration. In addition, we discuss current challenges related to mechanical stability, degradation rates, and clinical translation, while highlighting future directions for optimizing these next-generation bioactive hydrogel systems in regenerative dentistry. Full article

Endophytic fungi (EF) are microorganisms that colonize the internal tissues of host plants, providing a range of benefits to them. In this symbiosis, they act as a reservoir of bioactive metabolites that are important for enhancing the host’s defense mechanisms as a resistance against pathogens. These molecules usually possess antimicrobial properties that can be exploited for application in agriculture and medicine. In this context, the current work was designed to evaluate the phytotoxic and antimicrobial properties of the endophytic fungus Curvularia inaequalis, isolated for the first time from the Iranian medicinal plant Echium khuzistanicum. Culture filtrates, their organic extracts, and isolated metabolites were tested against a series of plants to assess their phytotoxicity, as well as against a wide range of plant and human pathogens to evaluate their antimicrobial activity. The main compounds characterizing the organic extract of C. inaequalis have been identified as (R)-phomalactone, catenioblin A, and (-) asperpentyn (1–3) by using spectroscopic techniques, NMR mainly, and HR-ESI-MS. In the bioactivity evaluation carried out in this study, (R)-phomalactone (1) stood out as the most promising compound, exhibiting significant non-host phytotoxic activity on tomato leaves; potent antibacterial activity against a wide range of human pathogens, including methicillin-resistant Staphylococcus aureus (MRSA) strains; and marked antifungal activity against several economically important phytopathogens. (–)-Asperpentyn (3) also showed robust and selective antifungal activity against phytopathogens, while catenioblin A (2) exhibited only a slight phytotoxic effect and limited overall bioactivity in this study. These findings reveal that the isolated endophytic fungi hold considerable promise as an untapped source of bioactive metabolites with antibacterial, antifungal, and phytotoxic activities. Full article

The prevalence of infectious diseases is steadily increasing. If left untreated, they can lead to more serious health problems. Antibiotics currently available on the market are facing growing resistance, prompting the development of increasingly powerful antibacterial molecules. One alternative currently under investigation is the use of antibacterial peptides, whose mechanisms of action differ from those of conventional drugs. These peptides are produced naturally by all living organisms and can also be synthesized. However, as peptide chains become longer, synthesis and purification become increasingly complex and laborious. For decades, antimicrobial peptides have been synthesized on polymer supports using automated systems. Unfortunately, longer chains tend to fold more, preventing access of reagents within the cross-linked polymer network. Recombinant production of antimicrobial peptides has been achieved in various organisms called “cell factories,” allowing for more sustainable synthesis. Recently, microalgae have emerged as a promising and sustainable alternative for the production of antimicrobial peptides. They are inexpensive, easy to cultivate, and capable of producing biologically valuable molecules, offering a potential solution to antibiotic resistance. This work reviews the current state of these “cell factories” and examines the advantages and limitations of microalgae for the future of biopharmaceutical production. Full article

The main objective of the study was to choose the best salicylic acid-based monomers through in silico research to improve the antibacterial effects of dental prostheses, refine the synthesis process of such monomers, and examine their antibacterial and antifungal properties in vitro, forecast the long-term stability in an oral biological environment using molecular docking software and synthesizing new copolymers. Based on their strong antibacterial activity and low toxicity compared to other derivatives, the allyl ester of salicylic acid (AESA) and the allyl ester of acetylsalicylic acid (AEASA) were chosen as the study objects. Salicylic and acetylsalicylic acids were esterified with allyl alcohol and allyl bromide in a variety of solvents and temperatures to synthesize AESA and AEASA. The optimal conditions were identified with a yield of 78%. IR spectroscopy was used to confirm the chemical structure of synthesized molecules. In the presence of peroxybenzoyl, the regularities of the polymerization process between the obtained monomer and oligoethylene macromonomer (PEMM) were examined. To obtain new antibacterial oligomers containing a salicylic group and to study their physico-chemical properties, a technology for obtaining the copolymers of AESA with PEMM was developed, and their physical, mechanical, and antimicrobial properties were studied. Full article

Bacterial contamination and the escalating crisis of antibiotic resistance represent pressing global public health threats, with approximately 4.95 million deaths linked to antimicrobial resistance (AMR) in 2019 and projections estimating up to 10 million annual fatalities by 2050. As third-generation antimicrobial materials, metal–organic frameworks (MOFs) have emerged as promising alternatives to conventional agents, leveraging their unique attributes such as high specific surface areas, tunable porosity, and controlled metal ion release kinetics. This review provides a systematic analysis of the foundational principles and core antibacterial mechanisms of MOFs, which include the sustained release of metal ions (e.g., Ag⁺, Cu²⁺, Zn²⁺), the generation of reactive oxygen species (ROS), and synergistic effects with encapsulated functional molecules. We highlight how these mechanisms underpin their efficacy across a range of applications. Rather than offering an exhaustive list of synthesis methods and metal compositions, this review focuses on clarifying structure–function relationships that enable MOF-based materials to outperform conventional antimicrobials. Their potential is particularly evident in several key areas: wound dressings and medical coatings that enhance tissue regeneration and prevent infections; targeted nanotherapeutics against drug-resistant bacteria; and functional coatings for food preservation and water disinfection. Despite existing challenges, including gaps in clinical translation, limited efficacy in complex multi-species infections, and incomplete mechanistic understanding, MOFs hold significant promise to revolutionize antimicrobial therapy. Through interdisciplinary optimization and advancements in translational research, MOFs are poised to drive a paradigm shift from “passive defense” to “active ecological regulation”, offering a critical solution to mitigate the global AMR crisis. Full article

Background/Objectives: Pinostilbene is a naturally occurring methoxylated stilbene with many beneficial health properties, including antioxidant, antimicrobial and neuroprotective activities. This stilbene has also been shown to possess anticancer or cytotoxic activity in some cancers. As in the case of other stilbenes, pinostilbene is very labile, degrades rapidly under stress conditions and is poorly water-soluble, which poses a drawback to its use as a drug. This work aims to provide further insights into its cytotoxicity activity in a colon cancer cell line and to overcome its physicochemical limitations by encapsulating the molecule in cyclodextrins. Methods: The anticancer activity was evaluated in vitro in Caco-2 colorectal cells using the neutral red assay. Subsequently, a screening of cyclodextrins was carried out to determine the one with the highest encapsulation constant, as well as the encapsulation stoichiometry, using fluorescence spectroscopy and molecular docking predictions. The formation of the inclusion complexes was checked by differential scanning calorimetry and scanning electron microscopy. The protective effect of cyclodextrins on pinostilbene release was monitored through spectrophotometric measurements over time. Results: Pinostilbene showed in vitro cytotoxicity activity in Caco-2 colorectal cells by the neutral red assay. This study revealed that the cyclodextrin with the highest encapsulation constant was the hydroxypropyl-β-cyclodextrin (K_F = 10,074.45 ± 503.72 M⁻¹), and the encapsulation stoichiometry was 1:1. DSC and SEM assays confirmed the formation of these inclusion complexes. Cyclodextrins were able to satisfactorily reduce pinostilbene degradation from 31% to less than 15% after 3 months, as well as increase its water solubility up to 10 times and enhance its release as a function of the pH of the medium. Conclusions: Pinostilbene is a promising drug candidate with strong in vitro antiproliferative activity. Many of its physicochemical limitations can be overcome with cyclodextrins, which opens the door to its future use in the pharmaceutical and food industries. Full article

Background: Hepcidin not only sustains systemic iron homeostasis but also functions as an antimicrobial peptide. During this study, we sought to analyze the ability of hepcidin to protect against sepsis-associated acute kidney injury (SAKI) and elucidated its underlying mechanisms in mediating ferroptotic pathways. Methods: A SAKI mouse model was created via cecal ligation and puncture (CLP), along with an LPS-induced Human Kidney-2 (HK-2) cell model, to study the protective mechanism of hepcidin against SAKI. Through the analysis of renal injury biomarkers and ferroptosis-related molecules, combined with quantitative detection of nuclear factor-erythroid 2-related factor-2 (Nrf2) nuclear translocation and glutathione peroxidase 4 (GPX4), a regulatory protein of ferroptosis, we uncovered the hepcidin-mediated mechanisms underlying ferroptosis in SAKI. Results: Hepcidin significantly attenuated renal function impairment in mice with SAKI and reduced the sepsis-driven increase in inflammatory mediators. As sepsis was associated with enhanced renal ferroptosis, hepcidin exerted a therapeutic effect by mitigating ferroptosis to a degree comparable with that of the ferroptosis inhibitor Ferrostatin-1 (Fer-1). Furthermore, hepcidin conferred renoprotective effects in SAKI by promoting the nuclear translocation of Nrf2, which in turn mediated the upregulation of the downstream anti-ferroptotic protein GPX4. Importantly, the Nrf2 inhibitor ML385 abrogated both the hepcidin-induced nuclear translocation of Nrf2 and the subsequent increase in GPX4 expression. Conclusions: Protective effects of hepcidin against SAKI are mediated by the Nrf2/GPX4 ferroptosis pathway, underscoring its therapeutic potential for SAKI. Full article

Unlike other animals, marine invertebrates lack an adaptive immune system and instead rely on innate immunity as their first line of defense. A key component of this innate response is the production of biologically active molecules, particularly antimicrobial peptides (AMPs), which offer promising solutions to the escalating global crisis of antimicrobial resistance (AMR). This review comprehensively examines the sources, structural diversity, mechanisms of action, biological functions, and therapeutic potential of AMPs derived from a wide range of marine invertebrate phyla. These evolutionarily conserved peptides exhibit broad-spectrum antibacterial, antifungal, antiviral, antiparasitic, and even anticancer activities. The review also summarizes strategies for AMP isolation and production, ranging from natural extraction to recombinant expression and chemical synthesis, and outlines their potential biotechnological applications. Furthermore, we highlight the transformative role of artificial intelligence (AI) in accelerating AMP discovery, design, and production, including predictive modeling, de novo peptide generation, and optimization workflows. Despite significant progress, challenges remain in large-scale production, pharmacokinetic characterization, and functional validation. Addressing these gaps through integrative omics, structural biology, and AI-driven innovation will be crucial for unlocking the full therapeutic potential of marine invertebrate AMPs in combating infectious diseases and antimicrobial resistance. Full article