Search Results (1,294)

The utilization of grape seeds, a by-product of winemaking, and the production of valuable bioactive products from them is a very promising concept in the field of industrial waste management. The aim of this study was to investigate the effect of grape variety and storage conditions on the polyphenol stability and antioxidant capacities of grape seed extracts over a long period of time (10 months). The separated seeds from the pomace of the red grape varieties Cabernet Sauvignon and Cabernet Franc were dried at 23 °C for 10 days and at 40 °C and 60 °C for 24 h. The polyphenol extraction from all types of dried seeds was carried out under the same conditions: 70% aqueous ethanol, magnetic stirring at 600 rpm, for 3 h. Seeds dried at 40 °C yielded extracts with the highest total phenolic content. The extracts obtained from them were prepared in three physical forms: liquid concentrated form, lyophilized form and dried form at 40 °C. All the obtained extract forms were stored at 4 °C and 23 °C for 10 months. The effects of grape variety, extract physical forms and extract storage conditions on the total phenolic content, total flavonoids, procyanidins and antioxidant capacity of the extracts were studied. All parameters were determined at 0, 3, 6 and 10 months. It was found that the two types of dried extracts showed the highest stability of polyphenols at 4 °C for 10 months. The loss of total phenolic content of lyophilized Cabernet Franc GSE under these conditions was only 8.17%. All the physical forms of Cabernet Franc GSE exhibited lower losses of antioxidant activities compared to those of the Cabernet Sauvignon GSE. It was found that the reduction of antioxidant activity followed first-order kinetics. The individual compounds of the liquid and lyophilized Cabernet Franc and Cabernet Sauvignon seed extracts stored at 4 °C and 23 °C for 0 and 10 months were determined by HPLC, and their percentage loss was calculated. After 10 months of storage, the greatest degradation losses were recorded for gallic acid, procyanidin C1 and epicatechin, followed by procyanidin B3. Among the analyzed polyphenolic compounds, procyanidin B1 demonstrated the highest stability, with a loss of only 0.6%, followed by catechin and procyanidin B2, with losses of 4.02% and 2.35%, respectively. The effect of differences in the chemical composition of the two grape varieties on the stability of polyphenols and antioxidant activity of the extracts was also evaluated. Full article

A simple and efficient QuEChERS-HPLC-DAD method was developed and validated for the simultaneous determination of benzoic acid, sorbic acid, and eight parabens in diverse food matrices. The sample preparation procedure was systematically optimized by evaluating the extraction solvent composition, salting-out conditions, and dispersive solid-phase extraction clean-up to achieve satisfactory recoveries while minimizing matrix interferences. Chromatographic separation was accomplished using isocratic elution on a C18 column with dual-wavelength ultraviolet detection, enabling the simultaneous determination of both authorized preservatives and non-authorized parabens within a single analytical run. The validated method exhibited excellent linearity (R² > 0.996), low to moderate matrix effects (within ±20%), satisfactory recoveries (79–112%), and good precision (RSD < 7.3%), meeting the performance criteria for routine residue analysis. The applicability of the method was demonstrated by analyzing commercial food samples from six food categories. Benzoic acid and sorbic acid were the most frequently detected preservatives, whereas only methylparaben and propylparaben were identified among the investigated parabens. No non-authorized parabens were detected in the analyzed samples. Owing to its simplicity and reliability, the proposed QuEChERS-HPLC-DAD method represents a practical analytical approach for routine multi-matrix monitoring of food preservatives in quality control and food safety laboratories. Full article

Large amounts of banana leaves are discarded as agricultural waste during banana harvesting; however, they are rich in bioactive compounds with promising exploitation potential. The ethyl acetate fraction contains the highest levels of total phenolics and total flavonoids together with strong antioxidant activity, which renders it a candidate source of natural antioxidants. In our current study, HPLC fingerprints were constructed for ten batches of ethyl acetate extracts from banana leaves (BLEA), and fingerprint similarity evaluation coupled with statistical analysis of common peak areas was carried out. Meanwhile, an HPLC quantitative method was developed to simultaneously determine eight characteristic components. The similarity values between the fingerprints of ten batches and the reference fingerprint ‘R’ ranged from 0.791 to 0.988. Cluster analysis (CA) and orthogonal partial least squares discriminant analysis (OPLS-DA) yielded consistent results, revealing clear separation trends among samples from different batches. In this quantitative method, eight characteristic analytes showed favorable linearity within their respective concentration ranges (r ≥ 0.9997). The average recoveries ranged from 101.6% to 104.3%, with RSD of 0.32% to 0.84%, demonstrating that the quantitative method was accurate and reliable. HPLC fingerprint combined with multi-component content determination offers a scientific basis for the quality evaluation and biomass valorization of banana leaves. Full article

Artemisia annua L. is a medicinal plant characterized by a chemically diverse phytochemical profile and potential relevance for cosmetic and dermatological applications. This study investigated a hydroethanolic A. annua extract through phytochemical characterization, antioxidant evaluation, UV–Vis-based assessment of UV absorption, and exploratory molecular docking. HPLC-DAD-MS/MS supported the assignment and quantitative determination of artemisinin, chlorogenic acid, and isoquercitrin at 0.09, 0.11, and 0.21 mg/mL extract, respectively. GC–MS revealed a diverse composition comprising primary and secondary metabolites, while separate essential oil characterization identified Artemisia ketone as the predominant volatile constituent. Total phenolic and flavonoid contents were 16.82 ± 0.29 mg GAE/g DW and 1.46 ± 0.14 mg RE/g DW, respectively. Concentration-dependent antioxidant activity was observed in DPPH and ABTS assays, with IC₅₀ values of 0.77 ± 0.13 and 0.092 mg dry plant material equivalent/mL reaction mixture, respectively. UV–Vis analysis showed concentration-dependent increases in spectrophotometrically estimated SPF within the evaluated analytical range. At 1.25 mg/mL, the extract exhibited an SPF estimate of 7.20 ± 0.35, a UVA/UVB absorbance ratio of 2.58, and a critical wavelength of 379.3 nm, indicating that UV absorption extended substantially into the UVA region. Exploratory molecular docking yielded the most favorable AutoDock Vina scores for chlorogenic acid toward MMP-1 (−9.0 kcal/mol) and isoquercitrin toward human neutrophil elastase (−8.0 kcal/mol). Overall, A. annua represents a source of phytochemicals with experimentally demonstrated antioxidant activity and measurable UV-absorbing properties, supporting further investigation in appropriately formulated and validated topical systems. Full article

Background/Objectives: The aim of this study was to develop and validate a simple, accurate, reproducible, and sensitive reverse-phase high-performance liquid chromatography method for the quantification of reproxalap (RP) in cyclodextrin (CD) inclusion complexes and poloxamer 407 hydrogel formulations. Methods: Chromatographic separation was achieved using a mobile phase of deionized water and an organic phase (methanol:acetonitrile, 55:45 v/v) in a 40:60 (v/v) ratio, at a flow rate of 0.9 mL/min and a run time of 10 min. Validation assessed linearity, specificity, accuracy, and sensitivity over a concentration range of 1–60 μg/mL. Phase-solubility studies were conducted to determine the apparent stability constant (K_1:1), and inclusion complexes were characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry. Results: The method demonstrated specificity, linearity, sensitivity, and accuracy within the tested concentration range of 1–60 μg/mL. The apparent stability constants (K_1:1), calculated from the phase-solubility plot slopes, were 2666.66 M⁻¹ for Sulfobutyl Ether β-Cyclodextrin (SBE-β-CD) and 526.3 M⁻¹ for Hydroxypropyl-β-Cyclodextrin (HP-β-CD). The solubility of RP in deionized water (0.25 mM) increased 8.6-fold to 2.15 mM with the HP-β-CD inclusion complex and 22.4-fold to 5.6 mM with the SBE-β-CD inclusion complex. The method was successfully applied to determine RP in inclusion complexes and poloxamer 407 hydrogel formulations, with no interference from formulation excipients. Conclusions: The validated RP-HPLC method is suitable for quality control analysis of RP in CD inclusion complexes and poloxamer 407 hydrogel formulations, supporting its application in the future development of these drug delivery systems. Full article

Triazole fungicides (TFs) are widely used in cereal production due to their potent fungicidal activity and broad-spectrum efficacy. Nonetheless, residues of TFs in food products may pose risks to food safety and human health. Therefore, the development of efficient and environmentally friendly sample preparation methods is paramount for the reliable determination of TFs. Herein, a novel green solvent-based dispersive liquid–liquid microextraction method coupled with high-performance liquid chromatography (DLLME-HPLC) was developed for the determination of TFs in cereal samples. The prepared magnetic deep eutectic solvents (MDESs), composed of nonanoic acid and ferric hydroxide, served as green, magnetically responsive extraction solvents, enabling rapid magnetic separation without centrifugation. Four bio-based solvents (BBSs) were investigated as green dispersive solvents to facilitate the dispersion of MDESs and replace conventional toxic organic dispersants, thereby further enhancing the environmental sustainability of the extraction procedure. Owing to the combined effects of hydrophobic interactions, hydrogen-bonding networks, and magnetic responsiveness, the proposed method achieved efficient extraction and rapid phase separation while minimizing solvent consumption and operational complexity. The greenness of the method was evaluated using multiple green analytical chemistry metrics, confirming its low environmental impact, reduced waste generation, and improved operational safety compared with conventional DLLME procedures. Under optimized conditions, the method was successfully applied to determine TFs in rice, wheat, corn, buckwheat, and oat samples, achieving recoveries ranging from 75.0% to 101.9% and relative standard deviations of 1.6–4.8%. The developed DLLME method provides a rapid, sensitive, and environmentally friendly strategy for cereal pesticide residue analysis and expands the application of MDESs and BBSs in green sample preparation. Full article

Rubus saxatilis L. (Rosaceae) is used in traditional medicine in Central Kazakhstan, yet the effect of the extraction method on its phenolic profile and biological activity has not been studied systematically. Three extracts were compared: two prepared by ultrasound-assisted extraction differing only in solvent—water (WE) and 50% ethanol (UAE)—and one by microwave-assisted extraction with 50% ethanol (MAE), allowing the effect of solvent (WE vs. UAE) and of extraction technique (UAE vs. MAE) to be assessed separately. Phenolic composition was determined by HPLC-UV-ESI-MS; antioxidant activity in vitro; cytotoxicity for Artemia salina; and antigenotoxic effects using Escherichia coli K12 MG1655 lux-biosensors (pKatG::lux, pSoxS::lux, pColD::lux) and Drosophila melanogaster models. Four phenolics were identified, with gallic acid dominant in the UAE and MAE extracts and hyperoside predominant in WE, while rutin was not detected in WE. MAE showed the strongest radical-scavenging activity (DPPH, IC₅₀ = 7.44 µg/mL), whereas WE had the highest reducing power (FRAP, EC₅₀ = 52.97 µg/mL). All extracts were non-toxic for A. salina and induced neither oxidative stress nor the SOS response; instead, they attenuated dioxidine-induced SOS signalling by up to 57%, suggesting an antigenotoxic (DNA-protective) effect at the bacterial level. In Drosophila, extracts produced moderate extract-dependent genotoxicity: the lowest damage was observed for MAE. The extraction method governs the phenolic profile and biological activity of R. saxatilis, with MAE being most favorable. Full article

The persistence of antibiotics like ciprofloxacin (CIP) in aquatic environments necessitates the development of efficient, low-cost wastewater treatment technologies. This study investigates a low-temperature fabrication strategy for mixed-phase copper oxide (CuO/Cu₂O) coatings synthesized via co-precipitation and immobilized using electrophoretic deposition (EPD). A critical finding was that a 25 min precursor aging time (T25) preserved a metastable mixture of CuO and Cu₂O phases, which is highly advantageous for creating heterojunction interfaces that enhance charge separation. In contrast, extended aging (T35) promoted phase consolidation toward bulk CuO, reducing catalytic surface area. During the EPD process, applied voltage acted as an influence to the relative phase composition and deposition behavior of the deposited coatings; 1.0 V was identified as the optimal condition, balancing high phase fidelity with enhanced crystallinity (average crystallite size of 30.6 nm) and mechanical stability. Photocatalytic experiments demonstrated significant CIP degradation, with the 0.9 V and 1.0 V films outperforming the 1.2 V film, possibly due to more favorable surface chemistry and phase diversity. While the 0.9 V film achieved the highest mineralization efficiency (18% TOC removal), the 1.0 V film offered the best balance between photocatalytic activity, structural stability, and phase selectivity for practical applications. High-Performance Liquid Chromatography-Mass Spectrometry HPLC-MS analysis suggested that degradation proceeds through oxidative pathways involving piperazine ring cleavage and defluorination. Full article

Reversed-phase chromatography stationary phases (such as C18) are widely used in commercial high-performance liquid chromatography (HPLC). However, when dealing with complex mixtures, they often exhibit limited separation capabilities and peak tailing phenomena. To address this problem, two novel HPLC stationary phases based on polyamine macrocycles were developed. A trianglamine macrocyclic stationary phase (TRI-Sil) was first prepared using chlorinated silica gel as the support, which can effectively separate a variety of aromatic compounds, but with limited selectivity for positional isomers such as phenylenediamine. To further improve the separation selectivity, a polyamine-silica macrocyclic stationary phase (CPAM-Sil) was synthesized by introducing a branched-chain-containing monomer. Under optimized conditions, CPAM-Sil achieved baseline separation of phenylenediamine and phenylenediol positional isomers and improved the separation of terphenyl isomers, with favorable asymmetry factors and high column efficiency compared with the commercial C18 column. Molecular docking confirmed multiple interactions such as electrostatic interactions and hydrogen bonding between the polyamine macrocycle (CPAM) and analytes. The CPAM-Sil column also exhibited good reproducibility and stability, showing promising potential for industrial application in chromatographic separation. Full article

Nursery-plant grading relies on morphological traits, but leaf metabolic variation associated with nursery-plant grade remains unclear. In this study, untargeted HPLC-QTOF-MS metabolomics was applied to mature and young leaves of Grade I, II, and III apple nursery plants to explore grade-associated metabolic variation and its relationship with growth performance. After quality filtering, 198 positive-ion features were retained from mature leaves, while 259 positive-ion and 8 negative-ion features were retained from young leaves. Multivariate analysis showed clear grade-associated separation in both leaf types, with stronger discrimination in young leaves. A combination of orthogonal partial least squares (OPLS) modeling and trend analysis identified 20 and 28 differential features in mature and young leaves, respectively. Cross-model prioritization further highlighted key metabolites putatively annotated as methyl nicotinate and 1-palmitoyl-sn-glycero-3-phosphocholine in mature leaves, and methyl nicotinate, nicotinamide riboside, cis-jasmone, and methyl (9Z,14Z)-12,13,16-trihydroxyoctadeca-9,14-dienoate in young leaves. These key metabolites were potentially associated with NAD precursor metabolism, membrane lipid remodeling, and oxylipin-related signaling. Correlation analysis showed that they were associated with both initial grading traits and post-transplant growth performance. These metabolites represent candidate molecular correlates of grade-associated physiological variation and growth performance in apple nursery plants. Full article

Background/Objectives: In this study, a novel reversed-phase high-performance liquid chromatography (RP-HPLC) method was established for the quality control of amiodarone hydrochloride, overcoming the limitations of the legacy compendial protocol. The conventional United States Pharmacopeia method requires a 10-fold sample dilution to avoid column overload and matrix interference from polysorbate 80. Attempting direct injection under conventional conditions severely compromises data reliability, leading to severe band broadening and peak distortion. Methods: To fairly evaluate the intrinsic separation capacity of the analytical systems, preliminary experiments were conducted using identical, undiluted dissolution samples. Through precise chromatographic redesign, the novel method eliminates the pre-treatment dilution step. Furthermore, the reliability, precision, and robustness of the proposed method were comprehensively validated in strict accordance with the International Council for Harmonisation Q2 guidelines. Results: Even upon direct injection of highly concentrated samples, the optimized system focuses broad peaks into sharp, symmetric, and narrow bands, increasing analytical sensitivity and theoretical plates. Furthermore, it maximizes intra-column separation efficiency, achieving complete baseline isolation of amiodarone from surfactant interferences within a retention time of approximately 6.6 min, thereby significantly improving analytical throughput. Conclusions: By eliminating cumbersome sample preparation, minimizing analysis time, and enhancing quantitative integrity, this validated RP-HPLC method offers an efficient, high-throughput standard analytical platform. It is highly suitable for rapid routine quality control and high-precision dissolution testing of generic amiodarone pharmaceuticals in industrial settings. Full article

The enantiomeric composition of products obtained from isomerization of n-humulone 1a to trans- and cis-n-isohumulones 2a and 3a, respectively, was determined by chiral HPLC analysis of the isolated trans and cis isomers. Enantiomers of humulone 1 were readily resolved on a Whelk-O1 chiral stationary phase (CSP), whereas the isomeric isohumulones 2 and 3 were separated on a carbohydrate-based IC-3 CSP. Magnesium-catalyzed isomerization of n-humulone under basic conditions gave mixtures of trans- and cis-n-isohumulones exhibiting an increasing preference for the cis isomer at lower temperatures. At either 10 °C in CH₂Cl₂/H₂O or reflux in methanol-water, the trans-(−) (4S,5S)-2a isomer was obtained in greater than 95% ee, while diastereomeric cis-3a exhibited 88% ee of the (+)-(4S,5R) enantiomer. Precision continuous flow photochemical isomerization using 395 nm LEDs provided trans-(−)-2a in greater than 95% ee in an isolated yield of 93%. However, photochemical isomerization with 365 nm LEDs gave a mixture of isomers consisting of 46% ee for the trans-(−)-2a and greater than 95% ee for the cis-(−)-(4R,5S)-3a enantiomer. The photochemically obtained (−)-3a isomer has the opposite absolute configuration compared to thermal isomerization. An oxadi-π-methane rearrangement is proposed to account for the formation of isohumulone isomers under photochemical conditions. Full article

Background/Objectives: Date seeds contain a wide range of biologically active constituents and have been associated with multiple health benefits. Our study aimed to evaluate the utility of biphasic aqueous methanol/chloroform extraction for separating diverse metabolites from powdered Malakabi Ajwa date seeds and to identify the most effective chromatographic and spectroscopic techniques for their comprehensive profiling and structural characterization. Methods: Biphasic extraction generated organic, aqueous, and insoluble phases. Proper chromatography-mass spectrometry and spectroscopy analytical tools were then utilized to profile the metabolites in the aqueous and organic phases. Results and Conclusions: In the organic phase, fatty acids and their methyl esters were identified using GC-MS and confirmed by ¹H NMR, while the absence of an O–H band in the FT-IR spectrum, together with ¹H NMR data, supported the natural esterification of these fatty acids. In the aqueous phase, UV-Vis spectroscopy and LC-MS revealed anthocyanin pigments, and LC-MS additionally detected four amino acids. HPLC was used to quantify and validate the sugar composition, and ¹H 1D and 2D NMR spectra enabled the assignment of α- and β-glucopyranose, β-fructopyranose, and sucrose signals. ³¹P NMR indicated that orthophosphate monoesters were the predominant phosphorus-containing compounds in both organic and aqueous phases. Overall, our findings show how an integrated chromatographic and spectroscopic workflow provides a robust strategy for comprehensive metabolite profiling of natural products such as Malakabi Ajwa date seeds. Full article

Background: Screening for hemoglobinopathies, particularly in Mediterranean countries, is primarily aimed at preventing beta-thalassemia. However, during such screening, numerous other Hb defects can be diagnosed, each with different clinical significance, including qualitative and quantitative variations in the alpha genes. Aims: In the present study, we describe a new variant of the HBA1 gene co-inherited with a previously described variant of the HBD gene in a diabetic patient tested for HbA1c. Methods: HbA1c and Hb fraction separation were performed using capillary electrophoresis (CE), and the Hb components were confirmed by high-performance liquid chromatography (HPLC). Molecular analysis was performed using next-generation sequencing (NGS). Results: The results of capillary electrophoresis and HPLC tests showed the presence of two anomalous peaks. The molecular study revealed the presence of a new variant of the HBA1 gene, which was named Hb Romagna, and a co-inherited variant of the HBD gene already known as Hb A2-Lampang. Discussion: The coexistence of the two variants poses certain diagnostic challenges with clinical implications that could be relevant to patient management. Full article

Liquid chromatography—including thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC/LC)—and gas chromatography (GC) are fundamental separation techniques in analytical chemistry, used for the separation, identification, and quantification of individual components in a mixture across a wide range of applications, from biochemistry, pharmaceutical, food, and environmental research to forensic analysis [...] Full article