Search Results (369)

Background: Predictive modeling of vaccine stability is an essential tool for accelerating development and ensuring product quality, particularly when long-term data are limited. To ensure high-quality input for accurate stability predictions, it is often necessary to allocate substantial analytical resources. Methods: This study demonstrates that integrating high-throughput screening (HTS) techniques such as ultraviolet–visible spectrophotometry (UV-VIS), intrinsic fluorescence and dynamic light scattering (DLS) with Advanced Kinetics Modeling (AKM) results in a synergistic approach, facilitating the development of robust predictive stability models. Results: Here, we applied AKM to a glycoconjugate vaccine targeting extra-intestinal pathogenic Escherichia coli (ExPEC). The aggregation processes observed via size-exclusion high-performance liquid chromatography (SE-HPLC), DLS, turbidity by UV-Vis absorbance and local changes in tryptophan microenvironment captured by intrinsic fluorescence were effectively described by the developed kinetic models. Conclusions: Using accelerated stability data across multiple temperatures, AKM successfully described key degradation pathways. Furthermore, the HTS assay results showed strong correlation with SE-HPLC data, indicating that these assays provide an efficient alternative requiring minimal analytical resources, material, and time. Full article

Background/Objectives: Coffea canephora (robusta) and Coffea liberica var. dewevrei (excelsa) cultivated in the Comoros islands represent understudied coffee varieties grown in a unique volcanic terroir. Despite their agricultural significance and potential bioactive value, no comprehensive biochemical or nutritional characterization of these Comorian coffees had previously been conducted. This study therefore aimed to provide the first integrated biochemical and nutritional characterization of both varieties and to evaluate the influence of the islands’ specific edaphoclimatic conditions on their chemical composition. Methods: An integrated analytical approach was employed, combining UV-Vis spectrophotometry, HPLC, ionomics, and FTIR-ATR spectroscopy to quantify polyphenols, flavonoids, caffeine, soluble sugars, antioxidant activity, mineral profiles, and macromolecular composition of green coffee beans from both species. Results: Robusta exhibited significantly higher levels of total polyphenols (121.79 ± 2.73 mg GAE/g), total flavonoids (29.43 ± 2.20 mg QE/g), caffeine (1.52% w/w), total soluble sugars (60.47 ± 3.37 mg GE/g), and antioxidant activity (64.97 ± 6.25 mM Trolox eq/g). Conversely, excelsa demonstrated a distinct mineral profile, with significantly higher concentrations of magnesium, calcium, sodium, zinc, and copper. FTIR spectroscopy confirmed distinct vibrational fingerprints between the two species, particularly in lipid and carbohydrate signatures. Conclusions: These findings position Comorian robusta as a potent source of antioxidants and stimulants, while excelsa offers a nutritionally balanced profile with nutraceutical potential, providing a scientific basis for valorizing both varieties as high-value niche products and contributing to the preservation of coffee agro-biodiversity. Full article

In this study, we compared the effects of microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE) on the total phenolic content, antioxidant activity, morphological characteristics, and tentative identification of bioactive compounds by LC-ESI-MS/MS in pomegranate seeds. We conducted a phytochemical characterization of the extracts by determining the total phenolic content and total flavonoids. Antioxidant activity was evaluated using ferric-reducing antioxidant power (FRAP) and free radical inhibition methods (DPPH and ABTS). Morphological characteristics were analyzed via scanning electron microscopy, UV-Vis and FTIR of the extracts were recorded. Additionally, the main bioactive compounds were identified using HPLC-MS. Our results demonstrated that MAE was the most efficient technique, yielding a higher content of total phenols (35.47 mg GAE/g), total flavonoids (14.44 mg CAE/g) and antioxidant activity (0.19 and 0.41 mmol TEAC/g, as determined by FRAP and ABTS, respectively). In terms of morphological characteristics, UAE induced more changes in the structure of the plant material compared to MAE. According to HPLC-MS analysis, the extract obtained using MAE notably contained coumaric acid, cyanidin, and quercetin, whereas the UAE extract included coumaric acid, cyanidin, kaempferol, and epicatechin. In conclusion, this study demonstrated that MAE is a more efficient method than UAE for extracting bioactive compounds. Pomegranate seeds may represent a potential source of these compounds for application in various industrial areas. Full article

Green synthesis is an eco-friendly, simple, and cost-effective process for the synthesis of metal nanoparticles from plant extracts that are rich in bioactive compounds. In the current study, the antioxidant potential and total soluble polyphenol content (TPC) of different parts of Ligusticum mutellina (L.) Crantz were evaluated using DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) assays, and the results indicated that the seed extract was the most active plant part. HPLC analysis indicated the presence of phenolic compounds such as gallic acid, protocatechuic acid, and catechin, which may contribute to the reduction and stabilization of AgNPs. Silver nanoparticles (AgNPs) were synthesized from the aqueous seed extract of L. mutellina. The formation of nanoparticles was confirmed by UV–Vis spectroscopy, FT-IR analysis, powder X-ray diffraction (PXRD), and transmission electron microscopy (TEM). The UV–Vis spectrum indicated a surface plasmon resonance peak at around 411 nm, and PXRD analysis indicated an average crystallite size of around 13 nm. TEM analysis revealed predominantly spherical nanoparticles with an average size of 25.36 ± 10.76 nm. The synthesized AgNPs exhibited strong antibacterial activity against Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. Overall, the results demonstrate that L. mutellina seed extract represents an effective natural source of reducing and stabilizing agents for green nanoparticle synthesis and highlight the potential of the obtained AgNPs as environmentally friendly antimicrobial materials. Full article

Removal of micropollutants from wastewater is currently drawing a lot of attention in the field of municipal wastewater treatment plants. Firstly, this is because of their unpredictable and potentially damaging fate in the environment, and secondly, due to newly established requirements in the relevant European Union Directive (EU) 2024/3019. This article assesses coagulation, oxidation with chlorine dioxide, sand biofilter, and their combinations as potentially cheaper and sustainable alternatives to well-established, but more expensive methods. For the experiments, citalopram, carbamazepine, and diclofenac were chosen as representatives of micropollutants. Removal efficiencies were evaluated using HPLC, COD, and absorbance UV/VIS at different wavelengths. The demand for chlorine dioxide was assessed using the chlorophenol red method. Owing to analytical limitations, the concentrations examined were in mg/L, which significantly exceeds actual concentrations found in wastewater. The application of stand-alone chlorine dioxide oxidation exhibited the best performance as it sufficiently removed citalopram and diclofenac. On the contrary, biodegradation was found to be the least efficient method, as none of the compounds tested were sufficiently removed in a short period of time. However, the results may be partially biased owing to high concentrations of the micropollutants assessed. In the following stage of the research, the evaluation of transformation products is desired to prevent such potentially harmful chemicals from entering the environment. Full article

Three cerium-based metal–organic frameworks (MOFs), Ce-BDC, Ce-BDC-NH₂, and Ce-BTC, were used as catalysts for the hydroxylation of several organic compounds, including those not relevant to environmental or biological systems. Structural characteristics were validated by FT-IR spectroscopy, while SEM imaging demonstrated rod-like morphologies of 100–200 nm in width for Ce-BDC-NH₂ and 50–100 nm for Ce-BTC. The optical properties, ascertained using diffuse reflectance spectra and Tauc analysis, revealed bandgaps of 3.0 eV, 2.9 eV, and 3.6 eV for Ce-BDC, Ce-BDC-NH₂, and Ce-BTC, respectively. Catalytic investigations revealed that Ce-MOFs effectively convert phenol into 1,4-dihydroxybenzene with an efficiency of 86–99%, as confirmed by UV–Vis spectroscopy and HPLC analysis using an authentic hydroquinone (1,4-dihydroxybenzene) standard. The Ce-MOFs efficiently oxidize the dyes methylene blue (MB) and Congo red (CR) and also promote the hydroxylation of L-tyrosine, indicating their relevance to biologically significant substrates. The high catalytic performance of Ce-MOF highlights the potential of Ce-based materials for environmental remediation, chemical transformation, and sustainable wastewater treatment. Full article

Aquifers are increasingly threatened by the uncontrolled release of non-biodegradable chemicals derived from anthropogenic activities. The development of new remediation strategies has therefore focused on the use of sustainable adsorbent materials, including synthetic organic hydrogels and biochars produced from agricultural residues. In this study, the removal of two organic pollutants, the herbicide Metribuzin (MEB) and Propyl Paraben (PrP), from aqueous environments was investigated using negatively charged hydrogels and biochars derived from lime peel, respectively. Propyl Paraben (PrP) and Metribuzin (MEB) are among the pollutants frequently found in aquatic environments, and the effective and sustainable removal approaches remain under investigation. The hydrogels studied (P(DMAM co-ANax)) were based on sodium methacrylate (ANa) copolymerized with N,N-dimethylacrylamide (DMAM). The adsorption performance of the materials was evaluated through UV-Visible absorption spectrophotometry and High-Performance Liquid Chromatography (HPLC). The results of this study showed that the hydrogel achieved a very high removal efficiency for MEB, which was over 80% for the concentration range studied (max $Q_e$ = 0.386 mg/g). Similar behavior was also recorded for the biochar from lime peel, which achieved almost complete removal of PrP (~100%) at the lowest concentrations of the contaminant (5 mg/L) and maintained high removal rates (78%) at 10 mg/L (max $Q_e$ = 0.187 mg/g). These results demonstrate the potential of both types of materials to efficiently remove the studied contaminants from water, indicating their suitability for environmental remediation applications. This work contributes to the development of cost-effective and eco-friendly adsorbents for the treatment of water pollution caused by emerging organic compounds. Full article

To address the challenge of purifying bioactive polyphenols from the complex matrix of Ziziphus jujuba Mill. var. spinosa pulp, this study established an integrated purification protocol combining Deep Eutectic Solvent (DES) extraction with macroporous adsorption resin (MAR) enrichment. Among five screened resins, AB-8 exhibited superior selectivity, achieving a maximum adsorption capacity of 62.48 mg polyphenols/g dry resin and a desorption ratio of 83.40%. Kinetic analysis revealed that the adsorption process strictly followed a pseudo-second-order model (R² = 0.999), indicating a mechanism dominated by chemisorption. Through dynamic optimization, optimal column parameters were determined as a loading concentration of 2.4 mg/mL, a flow rate of 1.0 mL/min, and elution with 70% (v/v) ethanol. Structural characterization via UV-Vis and FT-IR confirmed the effective removal of polysaccharide and protein impurities, while High-Performance Gel Permeation Chromatography (HPGPC) indicated a low-molecular-weight distribution (M_w approx. 1073 Da). Furthermore, HPLC-MS profiling definitively identified eight key constituents, including chlorogenic acid, catechin, rutin, and quercetin. Collectively, this work elucidates the adsorption mechanism and provides a scalable, efficient technical foundation for the high-purity preparation of jujube polyphenols. Full article

Selenium (Se) biofortification of vegetables can improve dietary Se intake; however, the dose-dependent balance between inorganic Se retention and organic Se assimilation following foliar selenate application remains insufficiently resolved across species. Five leafy vegetable species (garden rocket, wild rocket, dandelion, and two chicory cultivars) were grown under controlled greenhouse conditions and treated twice with foliar sodium selenate at increasing application rates (1 + 1, 2 + 2, 5 + 5, 10 + 0, 10 + 10, and 10 + 50 mg Se L⁻¹) across two experiments. Total Se and Se species were determined by HPLC-UV-HG-AFS following enzymatic extraction and cross-checked on selected extracts by HPLC-ICP-MS. Foliar selenate induced substantial Se accumulation in all species, reaching up to 102 µg g⁻¹ DW in garden rocket. At moderate application rates (notably 2 + 2 and 5 + 5 mg Se L⁻¹), a considerable proportion of extracted Se was converted into organic forms, with selenomethionine (SeMet) accounting for up to ~40% of total extracted Se. In contrast, at the highest application rate (10 + 50 mg Se L⁻¹), inorganic Se(VI) became predominant (often >40%), while SeMet proportion declined sharply to ~2–4%, indicating a saturation of metabolic assimilation capacity under high Se exposure. Leaf biomass was promoted at intermediate treatments (e.g., 5 + 5 and 10 + 0/10 + 10 mg Se L⁻¹), whereas the highest rate reduced growth. Overall, foliar selenate effectively biofortifies chicory, rocket, and dandelion leaves, but excessive application rates shift Se speciation toward inorganic storage and markedly suppress SeMet formation. These findings highlight the importance of dose optimization to maximize nutritional quality while avoiding metabolic overload. Full article

Fluoroquinolones (FQLs) are synthetic derivatives of the quinolone class, originally developed from the nalidixic acid scaffold. FQLs are widely used in human and animal medicine due to their broad spectrum of activity against Gram-positive and Gram-negative bacteria. Their strong bactericidal properties result from the inhibition of bacterial DNA transcription and replication. However, inappropriate use of these antibiotics often leads to toxic side effects, environmental pollution, and the development of antibiotic resistance in bacteria. Recently, numerous methods for determination of FQLs in various matrices have been developed using separation techniques such as high-performance liquid chromatography and capillary electrophoresis. In recent years, analytical procedures have employed a range of detection methods, including UV–Vis spectrophotometry, electrochemiluminescence, mass spectrometry, and fluorescence. Most of these procedures involve some form of extraction during the sample preparation step. This report summarizes the development of FQL determination methods over the last five years and may assist in selecting an appropriate procedure for a given sample matrix. Full article

Six different vinification treatments were applied to evaluate the effect of prefermentative ultrasound treatments on bioactive compounds and taste sensory attributes of autochthonous Croatian grape variety Malvazija istarska. Four of them were based on the application of a prefermentative ultrasound technique on cooled cryomacerated mash (at 10 °C for 24 h) as follows: ultrasound treatments of 70% amplitude for 80 min (US80-70%) and 160 min (US160-70%) and ultrasound treatments of 100% amplitude for the same durations as the previous (US80-100% and US160-100%). The research also included a control treatment C (wine produced using standard white winemaking technology without maceration) and a cryomaceration treatment lasting one day at 10 °C (CRIO). Phenolic compounds in wine were analyzed by HPLC-DAD-FLD, total phenolic content (TPC), antioxidant activity and color intensity by UV/VIS spectrophotometry, and sensory evaluation was performed using the QDA and 100-point O.I.V./U.I.O.E. methods. Ultrasound-treated wines exhibited the most pronounced increases in TPC, antioxidant activity and color intensity, as well as total hydroxycinnamic and hydroxybenzoic acids, flavonols, flavan-3-ols, stilbenes and the total HPLC phenolic concentration. All wines obtained after ultrasound treatments received the highest scores by both sensory methods, in the majority of sensory attributes, especially the US160-100% treatment. The differences observed between treatments indicate that both ultrasound amplitude and duration play a key role in optimizing extraction of phenolic compounds and improving sensory attributes of the wine. The results indicate that ultrasound treatments significantly enhance the bioactive composition and sensory profile of Malvazija istarska wines, highlighting their nutritional, health-related, and market potential. Full article

Polygonum cuspidatum, a traditional medicinal plant widely cultivated in Hubei Province, China, contains resveratrol, which has been shown to regulate lipoprotein metabolism, inhibit platelet aggregation, and aid in the prevention of arteriosclerosis and cardiovascular diseases. However, conventional extraction methods are often limited by low efficiency and solvent toxicity. A novel extraction strategy integrating an ultrasound-assisted extraction with natural deep eutectic solvents (NADES) was developed to achieve environmentally friendly and effective recovery of resveratrol from Polygonum cuspidatum. The optimized NADES system consisted of betaine and DL-malic acid in a 1:4 molar ratio with 50% water content. Using single-factor experiments and Response Surface Methodology, the following parameters were identified as optimum: solid–liquid ratio, 1:28 g/mL; ultrasonic power, 240 W; ultrasonic temperature, 40 °C; and ultrasonic time, 30 min. In such a case, the resveratrol yield reached 33.12 mg/g by UV-Vis spectroscopy and 2.95 mg/g by HPLC analysis, significantly higher than that obtained by other methods. Antioxidant assays demonstrated that the extract exhibited strong scavenging activity against ABTS⁺•, DPPH•, and •OH radicals. These results demonstrate that the ultrasound-assisted extraction with NADES method provides an efficient and eco-friendly alternative for extracting resveratrol from Polygonum cuspidatum, yielding extracts with notable antioxidant properties. Full article

Crocosmia is a genus of bulbous, perennial plants from the Iridaceae family whose characteristic red to orange pigmentation suggests the presence of anthocyanins, flavonoids, and carotenoids—secondary metabolites often associated with antioxidant activity. This study aimed to characterize and compare the major pigment-related metabolites in two Crocosmia varieties (Crocosmia masoniorum “Lucifer” and Crocosmia aurea) through chromatographic (HPLC-DAD) and spectrophotometric analyses (UV-Vis), using Crocus sativus L. flowers as a reference matrix. Successfully, the major crocin trans-4-GG, the flavonol kaempferol-3-O-β-sophoroside, and the anthocyanin delphinidin-3-O-β-glucoside were quantified in Crocosmia flowers. Additional metabolites absent in Crocus sativus L. were also identified and quantified. Both Crocosmia varieties exhibited higher antioxidant capacity than Crocus sativus L. flowers, highlighting their potential for future applications in pharmaceutical, nutraceutical, or functional ingredient development. Full article

This study includes a comparative analysis of four graphene-based electrochemical sensors used for the detection of melatonin, an endogenous hormone involved in circadian rhythm regulation and associated with various neurological pathologies. The sensors were based on screen-printed electrodes (SPE) modified with graphene (G), graphene modified with gold nanoparticles (AuNPs/G), graphene oxide (GO), and reduced graphene oxide (rGO). Melatonin was extracted from commercially available pharmaceutical products, purified, and characterized using UV-Vis spectroscopy, FTIR spectrometry, and HPLC. The performance of the electrodes was evaluated via cyclic voltammetry, using potassium ferrocyanide and standard melatonin solutions to determine the kinetic characteristics, while square-wave voltammetry was employed to determine the detection and quantification limits. G/SPE showed the best performance, with a detection limit of 0.3424 μM, followed by AuNPs/G/SPE with an LOD of 1.2768 μM. GO/SPE had the poorest performance (LOD 23.1056 μM), and rGO/SPE had an LOD of 5.8503 μM. Testing of sensors on pharmaceuticals showed accurate quantification of melatonin in a complex environment. The results highlight the potential of G/SPE and AuNPs/G/SPE sensors for use in the rapid and accurate detection of melatonin in pharmaceutical and biomedical applications. Full article

Symphytum officinale L. (Boraginaceae) is a plant with proven anti-inflammatory and analgesic activity on the musculoskeletal system. The traditional use of comfrey primarily refers to its roots, although some literature also mentions the leaves as an alternative plant material. Comparing the therapeutic potential of both plant materials requires additional data on the chemical composition of S. officinale leaves and their biological properties. The aim of the study was to analyze polyphenols in comfrey leaves of different origins and to assess their antioxidant and anti-inflammatory potential against comfrey roots, also collected from different sources. Polyphenol profiles were recognized by 2D TLC and HPLC-DAD-ESI-MS methods, and quantitative analysis was performed by the HPLC-UV/Vis (high performance liquid chromatograph with-ultraviolet/visible detection) method. The antioxidant activity was assessed using DPPH (2,2-diphenyl-1-picrylhydrazyl), FRAP (ferric reducing antioxidant power), and ABTS (2,2′-azino-bis(3-ethylbenzothiazoline- 6-sulfonic acid) diammonium salt) assays, and for leaves also using the TLC-DB (thin layer chromatography-direct bioautography) technique with the DPPH radical. Chemometric analysis to assess the relationship between the antioxidant activity and the origin of comfrey plant raw materials was performed. Factor analysis (FA) confirmed that geographic origin and cultivation conditions influenced the antioxidant content of both plant raw materials. The study results indicate that comfrey leaves can substitute for comfrey roots containing not only caffeic acid derivatives but also flavonoids, and exhibiting stronger antioxidant activity. Full article