Search Results (4,095)

Endoperoxides constitute a distinctive class of highly oxygenated terpenoids defined by the presence of a cyclic peroxide (–O–O–) bond, a structural motif responsible for their pronounced chemical reactivity and diverse biological effects. Naturally occurring endoperoxide-containing terpenoids are broadly distributed across terrestrial and marine taxa, including higher plants, algae, fungi, and bryophytes, where they are believed to participate in chemical defense and ecological interactions. This review provides a comprehensive overview of naturally occurring endoperoxide terpenoids, focusing on their natural sources, structural diversity, and reported biological activities. Particular emphasis is placed on compounds exhibiting antiprotozoal and antitumor activities, exemplified by artemisinin and its derivatives, which remain cornerstone agents in antimalarial therapy and continue to attract interest for their anticancer potential. Structure–activity relationship (SAR) analysis, supported by computational prediction using the PASS (Prediction of Activity Spectra for Substances) platform, is employed to examine correlations between peroxide-containing frameworks and biological function. Comparative assessment of experimental data and predicted activity profiles identifies key structural features associated with antiprotozoal, antineoplastic, and anti-inflammatory effects. Collectively, this review highlights endoperoxides as a valuable and chemically distinctive class of bioactive natural products and discusses their promise and limitations as leads for further pharmacological development, particularly in light of their intrinsic reactivity and stability challenges. Full article

Berries are a valuable source of health-promoting substances, including vitamins, microelements, and polyphenols. Optimising the extraction efficiency of these compounds during processing is crucial to minimise their loss into the waste stream. Ultrasound technology is recognised as a sustainable and promising tool for improving extraction; however, previous literature has not sufficiently addressed the optimal point of its application in fruit puree processing, and its impact on the sensory properties of the final product has only occasionally been explored. As one of the first reports, this study aimed to determine the optimal moment for ultrasound application within a puree production scheme. In the second stage of the experiment, four recipes based on strawberry and haskap berry were tested. The results demonstrated the potential for enhancing sensory quality of puree by using an ultrasound treatment. It was found that the ultrasound-treated purees showed significantly higher pectin levels and improved rheological properties, while the content of anthocyanins and L-ascorbic acid remained mainly unchanged. This indicates that the non-thermal nature of ultrasound treatment can induce positive changes from a sensory and rheological point of view without causing the degradation of health-promoting compounds, offering a viable strategy for improving berry puree quality. Full article

Background: Many inhibitors have been discovered to target hypoxia-induced carbonic anhydrase IX (CAIX) due to its critical role in lung cancers. This study discovers a novel compound, 3-(E-3,4-dihydroxycinnamaoyloxyl)-2-hydroxypropyl-9Z,12Z-octadeca-9,12-dienoate, which is produced by the seagrass Cymodocea serrulata and has binding sites at CAIX that are distinct from those of current inhibitors. Methods: Compound and reference drug treatment for cell lines; Cell viability: MTT; Staining: Ao/PI/DAPI; MMP shifts and cell cycle: FACS; Gene and protein expression of CAIX, BAX, BAD: qPCR and Western blotting. Results: The compound binds to the CAIX protein, raises extracellular pH, and kills A549 cells [IC₅₀: 11.61 µM], producing results that are lower than those of the reference drug doxorubicin [13.7 µM]. The substance depolarised the electrical potential of the mitochondrial membrane, caused S-phase arrest, and fragmented DNA. Additionally, it downregulated CAIX by 0.9 times while increasing apoptotic mRNA, BAX and BAD by 5.2 and 3.08 times, respectively, as demonstrated by qPCR. Between 0 and 24 h, the untreated hypoxic cells had a ΔpHe of 0.15, but the compound-treated cells had a ΔpHe of 0.6 indicative of intracellular acidosis. MD simulations verify the stability of the CAIX–C1 complex for more than 100 ns, and in silico studies show a strong binding affinity of the molecule to CAIX [−7.55 kcal/mol]. Conclusions: This implies that the amount of extracellular alkalosis was increased by the combination of treatment and hypoxia induction. As a result, when the cells were deprived of O₂, the compound provided less defense against ROS. The compound binds to the glutamine and alanine amino acids at positions 242 and 392, respectively, at the central Zn atom of CAIX, which sets it apart from conventional sulphonamide CAIX inhibitors. This naturally occurring compound may be a potent CAIX inhibitor with newer binding sites, which could help treat hypoxic lung cancers. Full article

Amaryllidaceae alkaloids are of notable pharmacological relevance. For instance, galanthamine is used in the treatment of Alzheimer’s disease, while other alkaloids (lycorine, crinine, etc.) derived from Amaryllidaceae plants are also of great interest because they exhibit antitumour, antiviral, antibacterial, antifungal, antimalarial, analgesic and cytotoxic properties. Phenolic acids comprise a group of natural bioactive substances that have commercial value in the cosmetic, food and medicinal industries due to their antioxidant, anticancer, anti-inflammatory and cardioprotective potential. In the present study, the effect of temperature (15, 20, 25 and 30 °C) on Amaryllidaceae alkaloid and phenolic acid biosynthesis in Leucojum aestivum in vitro plant cultures was investigated. The highest diversity of alkaloids (i.e., galanthamine, crinan-3-ol, demethylmaritidine, crinine, 11-hydroxyvitattine, lycorine, epiisohaemanthamine, chlidanthine) was noted in plants cultured at 30 °C. By contrast, ismine and tazettine were only present in plants cultured at 15 °C. Temperatures of 20 °C and 30 °C were found to stimulate galanthamine accumulation. The highest lycorine content was noted in plants grown at temperatures of 15 and 30 °C, and it was negatively correlated with the expression of the gene that encodes the cytochrome P450 96T (CYP96T) enzyme which catalyses a key step in the biosynthesis of different types of Amaryllidaceae alkaloids. This observation may reflect temperature-induced shifts in metabolic flux among different branches of Amaryllidaceae alkaloid biosynthesis. The observed stimulating effect of a 15 °C temperature on the chlorogenic, caffeic, p-coumaric, sinapic, ferulic and isoferulic acid content was in line with the highest expression of a gene that encodes the tyrosine decarboxylase (TYDC) enzyme, which is involved in plant stress response mechanisms. At 30 °C, however, the highest content of the caffeic, vanillic, p-coumaric and isoferulic acids was noted. Full article

Alicyclobacillus acidoterrestris is an acidothermophilic bacterium considered a significant challenge to the food industry, particularly in the production of fruit juices and concentrates. Its ability to survive pasteurization and form spores and biofilms makes it a persistent contaminant that can spoil products and generate off-flavors even during product storage. Recent studies have increasingly focused on developing new strategies to eliminate both vegetative cells and biofilms, with special attention on natural compounds such as plant extracts, essential oils and antimicrobial metabolites. These natural agents offer promising alternatives for controlling A. acidoterrestris and might contribute to improvement in safety and quality of juice products. This article presents a comprehensive overview of current strategies for controlling Alicyclobacillus species in food processing environments, with an emphasis on A. acidoterrestris as a major spoilage organism in the fruit juice industry. It summarizes the established physical and chemical control methods, as well as highlights emerging novel approaches involving natural-origin antimicrobial compounds considered useful for mitigating Alicyclobacillus contamination. Full article

Synthesizing natural substances has always been a significant challenge for organic chemists. The key to a successful total synthesis lies in utilizing reactions that generate molecular complexity with high stereocontrol. Photochemical reactions offer immense potential in this regard, though their complex mechanisms require careful mastery. This review explores recent examples from the literature where light-mediated reactions are crucial, often irreplaceable by thermal alternatives. The manuscript is organized by different photochemical processes, each introduced with relevant background. This review does not offer a complete analysis of all recent light-assisted syntheses; rather, it offers a glimpse into the growing trend of using photo-driven transformations to address significant synthetic challenges. Full article

Background/Objectives: Emerging biofilms of uropathogenic bacteria, particularly P. aeruginosa, on medical devices such as urinary catheters, lead to complications in the treatment of urinary tract infections (UTI). Considering the spread of antibiotic resistance, the search for alternative efficient control options for biofilms is of great medical interest. Methods: Curcumin, 1-monolaurin, n-undecyl-α/β-l-fucopyranoside, and the fungal metabolite terrein were investigated for their influence on biofilm formation by P. aeruginosa on latex catheter pieces in artificial urine (AU), monitoring the number of colony-forming units per cm Latex-Catheter (CFU/cm Latex-Catheter). Results: Significant inhibition of P. aeruginosa biofilm formation [55.6% CFU reduction/cm²] was observed with the fungal metabolite terrein at 256 µg/mL AU. At a concentration of 512 µg/mL AU, terrein achieved almost complete inhibition of biofilm formation. n-undecyl-α/β-l-fucopyranoside inhibited biofilm formation [58.3% CFU reduction/cm²] by P. aeruginosa ATCC 27853 at 512 µg/mL AU. Compared to that, it caused an increase in biofilm formation [87.0% CFU increase/cm²] by P. aeruginosa PA 01 at 256 µg/mL AU. This study is limited by the fact that no investigations into the possible cytotoxicity of the two active substances, terrein and n-undecyl-α/β-l-fucopyranoside, on healthy eukaryotic cells have been carried out. Conclusions: Natural substances may be a promising approach to prevent the formation of P. aeruginosa biofilms. For antibacterial applications, fungal metabolites, such as terrein, offer a novel approach to prevent biofilms in urological practice. Full article

Microbial contamination of food is a crucial cause of food spoilage and foodborne diseases, posing a severe threat to global public health. Although chemical preservatives are effective, their potential hazards to human health and the environment, coupled with the growing demand for “clean label” products, have driven the search for natural alternatives. Lactic acid bacteria (LAB), recognized as the Generally Recognized as Safe (GRAS) microorganisms, have emerged as the promising bio-preservatives due to their safety, effectiveness, and multifunctionality. This review systematically summarized the core antimicrobial properties of LAB, including their inhibitory spectrum against foodborne pathogens, spoilage microorganisms, viruses, parasites, and their ability to degrade toxic substances such as mycotoxins, pesticides, and heavy metals. Key inhibitory mechanisms of LAB are highlighted, encompassing the production of antimicrobial metabolites, leading to metabolism disruption and cell membrane damage, nutrition and niche competition, quorum-sensing interference, and anti-biofilm formation. Furthermore, recent advances in LAB applications in preserving various food matrices (meat, dairy products, fruits and vegetables, cereals) are integrated, including their roles in enhancing food sensory quality, extending shelf life, and retaining nutritional value. The review also discusses critical factors influencing LAB’s inhibitory activity (medium composition, culture conditions, ionic components, pathway regulator, etc.) and the challenges associated with the application of LAB. Finally, future research directions are outlined, including the novel LAB and metabolites exploration, AI-driven cultural condition optimization, genetic engineering application, nano-encapsulation and active packaging development, and building up the LAB-based cellular factories. In conclusion, LAB and their antimicrobial metabolites hold great promise as green and safe food preservatives. This review is to provide comprehensive theoretical support for the rational improvement and efficient application of LAB-based natural food preservatives, contributing to the development of a safer and more sustainable food processing and preservation systems. Full article

Procyanidins, a class of substances widely distributed in nature, have attracted the attention of the scientific community due to their bioactive properties, especially with regard to human health. This review is based on an extensive examination of peer-reviewed literature, patents, and clinical trial reports published between 2005 and 2025. From an initial pool of more than 300 documents, 283 studies were selected according to criteria of scientific rigor, methodological clarity, and relevance to the research objectives. A literature search was performed using PubMed, PubChem, Google Scholar, Scopus and ResearchGate employing keywords such as Procyanidins, chemical structure, extraction, and health effects. This article provides a comprehensive overview of current methods for obtaining these compounds, which include both natural sources and synthetic approaches. It provides a concise summary of the molecular structure of procyanidins and emphasizes the importance of understanding their conformational features for predicting biological activity. The challenges of establishing correlations between the structural features of procyanidins and their properties are described. In addition, this article explores the many potential applications of these compounds, spanning both biochemistry and the field of design and synthesis of novel materials. This review provides a comprehensive evaluation of Procyanidins, focusing on their geometrical conformation analysis through advanced NMR spectroscopy techniques including homonuclear correlation (COSY, TOCSY), heteronuclear one-bond (HSQC, HMQC), multiple-bond (HMBC) experiments, and through-space correlation (NOESY) in conjunction with various extraction methodologies. Full article

Melanin produced in melanocytes contributes to photoprotection, oxidative stress reduction, immune regulation, and epidermal homeostasis, while its dysregulation underlies diverse pigmentary disorders. Natural products modulate melanogenesis by regulating tyrosinase activity, intracellular signaling pathways such as extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) and cyclicAMP/protein kinase A/cAMP response element-binding protein (cAMP/PKA/CREB), and cellular redox balance. Anti-melanogenic effects have been reported for various fruit-derived phytochemicals, ginseng-based metabolites, and plant polyphenols, which act through direct enzymatic inhibition, suppression of melanoenic signaling, modulation of melanosome dynamics, and antioxidant or anti-inflammatory activities. Advances in delivery systems, including nano- and microencapsulation platforms, further enhance the stability and topical bioavailability of these compounds. In contrast, certain methoxylated flavonoids and phenolic constituents can stimulate pigmentation by sustaining melanogenic signaling and promoting microphthalmia-associated transcription factor (MITF)-driven transcription, emphasizing the context-dependent and bidirectional influence of natural substances on pigmentation outcomes. Collectively, these findings highlight the therapeutic potential of natural product-based modulators of melanogenesis while underscoring the need for mechanistic clarification, safety evaluation, and translational studies to ensure effective and controlled pigmentation management. This review summarizes the biological functions of melanin and examines natural strategies for regulating pigmentation. Full article

This investigation explored how seasonal variation affects the phytochemical composition and biological potential of Rosmarinus officinalis L., a widely used aromatic and medicinal plant. Aerial parts collected during spring, summer, autumn, and winter were extracted with ethanol and analyzed using LC-ESI-MS/MS, while total phenolic (TPC) and flavonoid (TFC) contents were determined spectrophotometrically. The extracts were evaluated for antioxidant, anti-inflammatory, enzyme inhibitory, analgesic, antimicrobial, cytotoxic, and photoprotective properties. Major constituents identified in all seasons included luteolin, kaempferol, rutin, and biochanin A. The autumn extract contained the highest phenolic (353.21 ± 4.05 µg GAE/mg) and flavonoid (190.11 ± 5.65 µg QE/mg) levels. Antioxidant assays revealed that the autumn extract had the strongest DPPH radical scavenging activity (IC₅₀ = 24.72 ± 0.16 µg/mL), while the spring extract exhibited the greatest reducing power (A_0.5 = 7.62 ± 0.30 µg/mL). The winter extract demonstrated superior anti-inflammatory activity (IC₅₀ = 28.60 ± 2.84 µg/mL), exceeding the reference drug diclofenac. Only the spring extract inhibited urease (IC₅₀ = 62.26 ± 0.58 µg/mL) and moderately inhibited α-amylase. All seasonal extracts showed notable photoprotective potential, with SPF values between 25.18 and 32.46, well above the recommended minimum. The spring extract also presented strong analgesic activity and no acute toxicity up to 2000 mg/kg. Antimicrobial effects were weak, limited to slight inhibition of Staphylococcus aureus, while moderate cytotoxicity was observed against MCF-7 and MDA-MB-231 breast cancer cells. Overall, seasonal variation significantly influenced the chemical profile and bioactivities of R. officinalis, with autumn and spring identified as the most suitable harvesting periods for pharmaceutical and cosmetic applications. Full article

Pervasive microplastics (MPs) and per- and polyfluoroalkyl substances (PFAS) frequently co-occur across aquatic and terrestrial environments due to shared sources, transport pathways, and persistence, yet their interaction-driven effects on environmental fate, bioavailability, and toxicity remain incompletely resolved. This review critically synthesizes current knowledge on the environmental co-occurrence of MPs and PFAS, the physicochemical mechanisms governing their interactions, and the resulting ecological and toxicological consequences across aquatic, terrestrial, and biological systems. Emphasis is placed on sorption and desorption processes; environmental modifiers such as pH, salinity, dissolved organic matter (DOM), and aging; and biological responses under combined exposure scenarios. Across laboratory and field studies, MPs–PFAS co-exposure is frequently associated with altered PFAS partitioning and enhanced organismal uptake, with reported bioaccumulation increases of up to ~2.5-fold relative to PFAS-only exposures. These changes are often accompanied by amplified oxidative stress, immune dysregulation, metabolic disturbance, and reproductive impairment, particularly in aquatic invertebrates and early life stages of fish. Evidence further indicates that the magnitude and direction of combined effects depend on polymer type, particle size, surface aging, and biological context, underscoring the highly system-specific nature of MPs–PFAS interactions. By integrating findings from environmental monitoring, laboratory toxicology, and mechanistic and modeling studies, this review identifies key knowledge gaps related to nanoplastics detection, environmentally realistic exposure conditions, sorption reversibility, and mixture toxicity assessment. Collectively, these insights highlight limitations in current single-contaminant risk frameworks and underscore the importance of incorporating MPs-mediated PFAS transport and bioavailability into exposure assessment and regulatory evaluation. Full article

This article describes the microbiome of the outer ear and the earwax in the ear canal, which performs various protective functions against bacterial infections. This article is based on an analysis of literature gathered from databases including PubMed, Google Scholar, Web of Science, and Scopus, primarily from the last 15 years. The search strategy included MeSH terms: ear canal, microbiome, earwax, cerumen, antibacterial peptides, ear infections, biofilm. Only peer-reviewed articles were included. The natural ear canal microbiota provides so-called colonization resistance, which protects against invasion by pathogenic microorganisms. Earwax is composed primarily of keratin secreted by epithelial cells and substances secreted by sweat and apocrine glands. It plays a key role in the physiology of the ear canal, maintaining a low pH, limiting moisture, and exhibiting antimicrobial properties. Both an excess and a deficiency of earwax can lead to dysbiosis of the outer ear, and consequently to the development of various infections. In an era of increasing antibiotic resistance and the search for new solutions in the fight against pathogenic microorganisms, understanding the natural properties of earwax is becoming increasingly important. Full article

The ongoing emergence of antiviral drug resistance underscores the critical need for new broad-spectrum antiviral agents. Sulfonamides and their derivatives have emerged as promising candidates for the development of new antiviral therapeutics. In this study, a series of camphor-10-sulfonamide derivatives was synthesized through a feasible and sustainable synthetic approach starting from naturally available precursors and evaluated for antiviral properties. Their activity was examined against three structurally distinct viruses—herpes simplex virus type 1 (HSV-1), human coronavirus (HCoV-OC43), and feline calicivirus (FCV)—representing both DNA and RNA, enveloped and non-enveloped types. The compounds were examined for their effects on viral replication, the stage of viral adsorption to the cell, and extracellular virions. The weakest cytotoxicity and the most pronounced activity of all the tested substances was demonstrated by the tryptophan derivative 7a. A time-dependent inhibition of the stage of adsorption of HCoV-OC43 (Δlg = 2.0 at 120 min) and FCV (Δlg = 1.75 at 60 min) to susceptible cells was established, as well as virucidal activity on the three types of virions tested, with the most pronounced effect at 120 min—for HSV-1 (Δlg = 2.75) and Δlg = 2.0 for HCoV-OC43 and FCV. Molecular docking studies performed using Glide (Schrödinger) provided insights into the active conformations of the most effective ligands and predicted possible interactions with relevant viral targets, supporting their potential as lead structures for further therapeutic development. Full article

The intestinal barrier is essential for gastrointestinal and systemic homeostasis by enabling nutrient absorption while limiting the translocation of pathogens and toxins. When barrier function is impaired, bacterial components such as lipopolysaccharides (LPSs) may cross the epithelium and promote inflammatory signaling. In dogs, chronic inflammatory enteropathies are frequent disorders associated with barrier dysfunction, dysbiosis, and immune dysregulation, and may progress to protein-losing enteropathy or systemic inflammation. Humic substances, particularly humic acid (HA), are natural organic compounds with reported antioxidative, immunomodulatory, and barrier-supporting effects; however, the cellular mechanisms underlying these effects in intestinal and immune models remain insufficiently characterized. This study evaluated the effects of a commercially available HA-based supplement on epithelial barrier integrity and inflammatory responses using an in vitro system combining IPEC-J2 intestinal epithelial cells and primary canine peripheral blood mononuclear cells (PBMCs). Epithelial barrier integrity (FD4 paracellular flux), reactive oxygen species, and cytokine production (TNF-α, IL-6) were assessed under basal and LPS-stimulated conditions. HA treatment preserved epithelial barrier function and reduced LPS-induced pro-inflammatory cytokine production, supporting further investigation of HA as a nutraceutical adjunct for gut health support in dogs with chronic enteropathies. Full article