Search Results (246)

Lepidium meyenii Walpers (syn. Lepidium peruvianum Chacon) has been cultivated for centuries in the Peruvian Andes as both a vegetable and a traditional medicine resource. Maca is classified as a superfood and is widely used as a dietary supplement, particularly noted for its potential to enhance endurance, fertility, and endocrine balance. In recent years, there has been a growing interest in the cytotoxic effects of lepidilines and their derivatives; however, these compounds have been less extensively studied due to challenges associated with their isolation. This study aims to establish optimal extraction conditions to enrich lepidiline content in the extracts and to propose an efficient isolation method for four lepidilines using a green purification technique known as Centrifugal Partition Chromatography (CPC). The isolated compounds will be evaluated for their anticancer potential utilizing the MTT assay on SK-N-SH (ATCC^® HTB-11™) and SK-N-AS (ATCC^® CRL-2137™) neuroblastoma cell lines. The findings indicate that Soxhlet extraction with dichloromethane resulted in the highest recovery of lepidilines, with a content of 10.24% expressed as lepidiline A. The optimal biphasic solvent mixture suitable for CPC chromatographic applications was identified as a combination of chloroform, methanol, and water (4:3:2 v/v/v) containing 60 mM HCl. When utilized in conjunction with semi-preparative high-performance liquid chromatography (HPLC), this method successfully isolated lepidilines A–D, achieving a purity exceeding 95%. Notably, lepidiline B exhibited the highest cytotoxic potential, with an IC50 value of 14.85 µg/mL in SK-N-AS cells. Full article

Background: A novel triple therapy regimen for Helicobacter pylori eradication, recently approved by the U.S. FDA, comprises vonoprazan (VPN), a potassium-competitive acid blocker, in combination with amoxicillin (AMX) and clarithromycin (CMN). This study presents the development and full validation of a rapid, selective, and sensitive LC-MS/MS method for the simultaneous quantification of these three drugs in spiked human plasma. Methods: Sample preparation was performed using a simple and efficient liquid–liquid extraction (LLE) technique. Chromatographic separation was achieved within 5 min using a Phenomenex Kinetex C18 column (100 × 4.6 mm, 2.6 µm) and a gradient elution system consisting of 0.1% formic acid in water and acetonitrile. Moreover, diazepam was used as an internal standard. The mass spectrometric detection was conducted in multiple reaction monitoring (MRM) mode using positive electrospray ionization. Results: The method exhibited excellent linearity over the investigated concentration ranges (2, 5, 10, 20, 50, and 100 ng/mL for amoxicillin and clarithromycin and 5, 10, 20, 30, 50, and 100 ng/mL for vonoprazan). Intra- and inter-day precision and accuracy values met FDA bioanalytical method validation guidelines, with relative standard deviations and relative errors below 15%. Mean absolute recoveries were above 93% for all analytes. Conclusions: The developed method was fully validated, rapid, selective, and sensitive LC-MS/MS and was assessed using the AGREE tool as a greenness assessment approach, confirming its environmental friendliness and alignment with green analytical chemistry principles. Full article

The increasing environmental concerns surrounding plastic waste have intensified recycling efforts, particularly in the textile industry, where poly(ethylene terephthalate) (PET) is widely used for sustainable material production. The growing use of recycled PET (rPET) in textiles has prompted the need for reliable analytical methods to detect and quantify rPET content. This study differentiates between virgin and recycled PET by simulating mechanical recycling through five reprocessing cycles of three distinct PET grades, assessing changes in crystalline structure, intrinsic viscosity, molecular weight, and specific degradation markers. Differential Scanning Calorimetry revealed bimodal melting behaviour in reprocessed samples, while intrinsic viscosity and Gel Permeation Chromatography indicated molecular degradation. Notably, the release of dimethyl terephthalate (DMT) and dimethyl isophthalate (DMiP) was consistently observed as a function of degradation. These markers were identified and quantified using High-Performance Liquid Chromatography (HPLC) and Gas Chromatography (GC), with GC offering higher sensitivity and lower matrix interference. This study demonstrates that DMT and DMiP are robust chemical indicators of PET degradation and recycled content. This analytical approach, combining thermal, rheological, and chromatographic techniques, provides a scientifically sound and potentially cost-effective basis for traceability systems, certification protocols, and regulatory compliance in sustainable textile production. Full article

The identification of plant oils in polychrome cultural relics is crucial for understanding historical craftsmanship and for developing appropriate conservation strategies. Historically, plant oils were used as binders, protective coatings, and plasticizers, directly influencing the stability and appearance of artifacts. Their degradation—through oxidation, hydrolysis, and environmental exposure—makes accurate detection challenging. Recent advances in spectroscopic methods (Fourier-Transform Infrared Spectroscopy, Raman), chromatographic techniques (Gas Chromatography–Mass Spectrometry, High-Performance Liquid Chromatography), and mass spectrometry imaging (Desorption Electrospray Ionization—Mass Spectrometry Imaging) enable non-invasive or minimally invasive analysis of oils, even within complex matrices. Case studies, including the Meiwu ceiling of the Palace Museum and resin–oil varnishes, illustrate how multi-method approaches improve reliability. Ongoing challenges include interference from degradation products, limited sampling due to ethical concerns, and the absence of comprehensive reference libraries. Future research should prioritize non-destructive techniques, standardized protocols, and interdisciplinary collaboration to enhance the precision and applicability of plant oil identification in cultural heritage conservation. Full article

Indoor sports facilities face distinctive indoor air quality (IAQ) challenges due to high occupant density, elevated metabolic emissions, and diverse pollutant sources associated with physical activity. This review presents a narrative synthesis of multidisciplinary evidence concerning IAQ in sports environments. It explores major pollutant categories, including carbon dioxide (CO₂), particulate matter (PM), volatile organic compounds (VOCs), and airborne microbial agents, highlighting their sources, behavior during exercise, and associated health risks. Research shows that physical activity can increase PM concentrations by up to 300%, and CO₂ levels frequently exceed 1000 ppm in inadequately ventilated spaces. The presence of semi-volatile organics and bioaerosols further complicates pollutant dynamics, especially in humid and densely occupied areas. Measurement technologies such as optical sensors, chromatographic methods, and molecular techniques are reviewed and compared for their applicability to dynamic indoor settings. Existing IAQ standards across China, the USA, the EU, the UK, and WHO are examined, revealing a lack of activity-specific thresholds and insufficient responsiveness to real-time conditions. Mitigation strategies (e.g., including demand-controlled ventilation, use of low-emission materials, liquid chalk substitutes, and integrated HEPA-UVGI purification systems) are evaluated, many demonstrating pollutant removal efficiencies over 80%. The integration of intelligent building management systems is emphasized for enabling real-time monitoring and adaptive control. This review concludes by identifying research priorities, including the development of activity-sensitive IAQ control frameworks and long-term health impact assessments for athletes and vulnerable users. Full article

Background: Liuwei Dihuang Pills, a classic traditional Chinese medicine formula, has been widely used in clinical practice for its multiple pharmacological effects. However, the systematic characterization and identification of its chemical constituents, especially the aqueous decoction, remain insufficient, which hinders in-depth research on its pharmacodynamic material basis. Thus, there is an urgent need for a comprehensive analysis of its chemical components using advanced analytical techniques. Methods: After screening chromatographic columns, the ACQUITY UPLC™ HSS T3 column (100 mm × 2.1 mm, 1.8 μm) was selected. The column temperature was set to 40 °C, and the mobile phase consisted of 0.1% formic acid in water (A) and 0.1% formic acid in acetonitrile (B). A gradient elution program was adopted, and the separation was completed within 20 min. Ultra-high performance liquid chromatography–Orbitrap mass spectrometry (UPLC-Orbitrap-MS) combined with a self-established information database was used for the analysis. Results: A total of 80 compounds were tentatively identified, including 13 monoterpenoids, 6 phenolic acids, 16 iridoids, 11 flavonoids, 25 triterpenoids, and 9 other types. Triterpenoids are mainly derived from Poria cocos and Alisma orientale; iridoids are mainly from Rehmannia glutinosa; monoterpenoids are mainly from Moutan Cortex; and flavonoids are mainly from Dioscorea opposita. Among them, monoterpenoids, iridoids, and triterpenoids are important pharmacodynamic components. The cleavage pathways of typical compounds (such as pachymic acid, catalpol, oxidized paeoniflorin, and puerarin) are clear, and their mass spectral fragment characteristics are consistent with the literature reports. Conclusions: Through UPLC-Orbitrap-MS technology and systematic optimization of conditions, this study significantly improved the coverage of chemical component identification in Liuwei Dihuang Pills, providing a comprehensive reference for the research on its pharmacodynamic substances. However, challenges remain in the identification of trace components and isomers. In the future, analytical methods will be further improved by combining technologies such as ion mobility mass spectrometry or multi-dimensional liquid chromatography. Full article

Polycyclic aromatic hydrocarbon (PAH) derivatives, specifically azaarenes and nitrated and oxygenated PAHs, are emerging contaminants of concern due to their increased toxicity and persistence compared to the parent PAHs. Despite their toxicity, their simultaneous analysis in complex matrices, such as in fumes emitted from bituminous mixtures, remains challenging due to limitations of conventional analytical techniques. To address this, an advanced methodology was developed using Ultra-High-Performance Liquid Chromatography coupled with High-Resolution Mass Spectrometry (UHPLC-HRMS Orbitrap Eclipse) equipped with an APCI source for the simultaneous identification and quantification of 14 PAH derivatives. Chromatographic and ionization parameters were optimized to ensure maximum sensitivity and selectivity. Following ICH Q2(R2) guidelines, the method was validated, demonstrating excellent linearity (R² > 0.99), high mass accuracy (≤5 ppm), strong precision (<15%), and excellent sensitivity. Limits of detection (LODs) ranged from 0.1 µg L⁻¹ to 0.6 µg L⁻¹ and limits of quantification (LOQs) ranged from 0.26 µg L⁻¹ to 1.87 µg L⁻¹. The validated method was successfully applied to emissions from asphalt pavement materials collected on quartz filters under controlled conditions, enabling the identification and quantification of all 14 targeted compounds. These results confirm the method’s robustness and suitability for trace-level analysis of PAH derivatives in complex environmental matrices. Full article

Due to the nearly identical chemical properties of Lu and Yb, the production of no-carrier-added (NCA) ¹⁷⁷Lu faces significant challenges in their separation. Achieving efficient and streamlined separation of Lu and Yb is crucial for the production of NCA ¹⁷⁷Lu. This study systematically investigated the separation performance of the commercial Rext-P350 extraction resin for Lu and Yb. Static adsorption experiments revealed that, at a solid–liquid ratio of 8 g/L, both Lu³⁺ and Yb³⁺ were nearly completely adsorbed, with saturation adsorption capacities of 25.8 mg/g and 21.5 mg/g, respectively. An increase in the nitric acid concentration in the aqueous phase significantly inhibited adsorption, but the separation factor for Lu³⁺/Yb³⁺ remained above 1.88. The adsorption kinetics followed a pseudo-second-order model (R² > 0.99), with equilibrium reached within 15 min, demonstrating fast adsorption kinetics. Characterization by SEM, FT-IR, and XPS confirmed the chemical coordination between the resin and Lu³⁺/Yb³⁺. Dynamic chromatographic separation experiments showed that the Rext-P350 resin exhibited significantly better separation performance for Lu³⁺/Yb³⁺ compared to 2-ethylhexylphosphoric acid mono-2-ethylhexyl ester (P507) extraction resin. Leveraging the excellent performance of Rext-P350 resin, a two-stage continuous extraction chromatography process was designed, achieving efficient separation of 0.045 mg of Lu³⁺ from 200 mg of Yb³⁺ with a Lu³⁺ purity of 90.9% and a yield of 98.4%. This study provides a feasible separation technique for the purification of NCA ¹⁷⁷Lu. Full article

Chiral liquid chromatography (cLC) using chiral stationary phases (CSPs) has become a crucial technique for separating enantiomers. Understanding enantiomeric discrimination is essential for improving chromatographic conditions and elucidating chiral molecular recognition; the computational methods are extremely helpful for this. To assess the relevance of the association of these two approaches and to analyze the current trends, in this review, a systematic analysis of the scientific literature was performed, covering recently published works (from 2015 to January 2025) on enantioseparation by cLC using CSPs and computational studies. CSPs based on polysaccharides and Pirkle-type were the most described (accounting for 52% and 14% of the studies, respectively). Regarding the computational methods, molecular docking and molecular dynamics (MD) were the most reported (accounting for 50% and 25% of the studies, respectively). In the articles surveyed, a significant growth in research concerning both cLC enantioseparation and computational studies is evident, emphasizing the benefit of the synergy between these two approaches. Full article

This study aimed to assess the extent of vitamin B₁ and B₆ vitamer loss during a single peritoneal dialysis (PD) session using a combination of chromatographic techniques and chemometric analysis. Dialysis effluent samples were collected from 41 PD patients (22 on continuous ambulatory peritoneal dialysis (CAPD) and 19 on automated peritoneal dialysis (APD)) during a standardised peritoneal equilibration test. Concentrations of thiamine monophosphate, thiamine diphosphate (ThDP), pyridoxine, pyridoxal (PL), and pyridoxamine were determined using high-performance liquid chromatography with a fluorescence detector. The analytical method was validated in terms of sensitivity, linearity, accuracy, and recovery. Multiple regression analysis was employed to identify potential clinical and demographic predictors of vitamin washout. All vitamers except pyridoxal 5-phosphate (PLP) were detectable in dialysis effluents. ThDP exhibited the greatest loss among the B₁ forms (ca. 0.05–0.57 mg/24 h), while PL exhibited the most significant loss among the B₆ forms (ca. 0.01–0.19 mg/24 h). Vitamin losses varied depending on the dialysis modality (continuous ambulatory peritoneal dialysis, or CAPD, versus automated peritoneal dialysis, or APD) and the peritoneal transport category. Regression analysis identified body weight, haemoglobin, and haematocrit as independent predictors of ThDP washout (R² = 0.58). No statistically robust models were established for the other vitamers. Even short medical procedures (such as single PD) can result in measurable losses of water-soluble vitamins, particularly ThDP and PL. The results emphasise the importance of personalised vitamin supplementation for PD patients and suggest that body composition and haematological parameters significantly influence the loss of thiamine. Full article

This study investigates the potential for the microbial transformation of camelliagenin B, a saponin derived from Camellia oleifera seed cake meal, to develop novel metabolites. We employed three microbial strains, specifically Bacillus subtilis ATCC 6633, Bacillus megaterium CGMCC 1.1741, and Streptomyces griseus ATCC 13273, to biotransform camelliagenin B into its derivatives. The compounds were purified and separated using chromatographic techniques, such as high-performance liquid chromatography (HPLC). Structural identification was carried out using spectroscopic methods, including nuclear magnetic resonance (NMR) and mass spectrometry (MS). Ten bioactive compounds were obtained (1a-1j), of which nine were novel with multiple tailoring reactions, such as allyl oxidation, C-C double-bond rearrangement, hydroxylation, dehydrogenation, and glycosylation, observed in camelliagenin B analogs. The structures of these compounds were determined by 1D/2D NMR and HR-ESI-MS analysis. Therefore, this study showcases the capacity of microbial transformation as a sustainable and environmentally friendly method for generating bioactive compounds from C. oleifera seed cake meals. The individual chemicals can potentially facilitate the design of novel medicinal agents, functional foods, and natural preservatives. Full article

The pisco industry generates significant environmental waste, particularly grape pomace, which is a rich source of phenolic compounds. Emerging extraction technologies offer promising alternatives for recovering these bioactive components. This study evaluated enzyme-assisted extraction (EAE) and pressurized liquid extraction (PLE) techniques using response surface methodology to optimize phenolic compound yield and antioxidant capacity. Specifically, a D-optimal design was applied for EAE, and a Box–Behnken design was applied for PLE. The optimal extraction conditions for EAE were 0.75 U/mL of tannase, 40 U/mL of cellulase, 20 °C, and 15 min. For PLE, the optimal parameters were 54% ethanol, 113 °C, and three extraction cycles. These conditions yielded 38.49 mg GAE g⁻¹ dw and 50.03 mg GAE g⁻¹ dw of total polyphenols and antioxidant capacities of 342.47 μmol TE g⁻¹ dw and 371.00 μmol TE g⁻¹ dw, respectively. The extracts obtained under optimal conditions were further characterized through chromatographic techniques to determine their phenolic profiles. Seven phenolic compounds were identified: gallic acid, catechin, epicatechin, 4-hydroxybenzoic acid, quercetin-3-rutinoside hydrate, quercetin-3-O-rhamnoside, and kaempferol. PLE extracts exhibited the highest concentration of these compounds. These findings demonstrate that recovering antioxidant-rich phenolic compounds from pisco grape pomace using innovative extraction methods is a viable strategy for obtaining functional ingredients and supporting sustainable industrial practices. Full article

The analysis of wastewater is essential in environmental chemistry, particularly for monitoring emerging contaminants and assessing ecological impacts. In this context, hyphenated chromatographic techniques are widely used, with liquid chromatography being one of the most common. However, gas chromatography coupled with mass spectrometry (GC-MS) remains a valuable tool in this field due to its sensitivity, selectivity, and widespread availability in most laboratories. This review examines the application of validated methods for wastewater analysis using GC-MS (MS), highlighting its relevance in identifying micropollutants such as pharmaceuticals, drugs of abuse, pesticides, hormones, and industrial by-products. The validation of analytical methods is crucial to ensuring the reliability and reproducibility of data and the accurate monitoring of contaminants. Key parameters, including sample volume, recovery efficiency, and detection and quantification limits, are discussed, evaluating different approaches to optimising the identification of different classes of contaminants. Additionally, this study explores advances in sample preparation techniques, such as solid-phase microextraction (SPME), dispersive liquid–liquid microextraction (DLLME), and solid-phase extraction (SPE), which enhance efficiency and minimise interferences in the analysis. Finally, future perspectives are discussed, including the integration of emerging technologies such as high-resolution mass spectrometry, the miniaturisation of GC systems, and the development of faster and more sustainable analytical methods. Full article

Sparkling wine is a complex alcoholic beverage with high economic value, produced through a secondary fermentation of a still wine, followed by a prolonged aging period that may last from nine months to several years. With the growing global demand for high-quality sparkling wines, understanding the biochemical mechanisms related to aroma development has become increasingly relevant. This review provides a comprehensive overview of the secondary fermentation process, with particular emphasis on yeast selection, types of closure, and the impact of aging on the volatile composition. Special attention is also given to the analytical strategies employed for the identification and quantification of target compounds in sparkling wine matrices. Due to the presence of volatile compounds at trace levels, effective extraction and pre-concentration techniques are essential. Extraction methods such as solid-phase microextraction (SPME), stir-bar sorptive extraction (SBSE), and thin-film SPME (TF-SPME) are discussed, as well as chromatographic techniques, such as gas chromatography (GC) and liquid chromatography (LC). Full article

Background/Objectives: Antimicrobial resistance represents a critical global health challenge that has been exacerbated by the significant decline in antibiotic development. Natural product-based drugs, particularly plant-derived phenolic compounds, offer promising alternatives to conventional antibiotics. This study aimed to isolate and characterize a novel phenolic compound from Bacopa procumbens, a Mexican perennial repent plant that is widespread in the Mexican valley and produces a variety of saponins, gastrodin derivatives, and phenolic acids, and to evaluate its antibacterial potential against clinically relevant pathogens. Methods: The hydroalcoholic extraction of B. procumbens was followed by liquid–liquid partitioning with ethyl acetate. The resulting fraction underwent chromatographic separation and purification. The structural elucidation of the isolated compound was performed using thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), mass spectrometry (MS-EI), and nuclear magnetic resonance (NMR) techniques. Antimicrobial activity was assessed via a microdilution assay against five bacterial strains, including drug-resistant Staphylococcus species and Gram-negative pathogens. Results: A novel phenolic compound, 5-(p-hydroxybenzoyl) shikimic acid (5pHSA), was isolated and characterized. The compound demonstrated moderate antibacterial activity against methicillin-resistant Staphylococcus haemolyticus and Escherichia coli (minimum inhibitory concentration (MIC) = 100 μg/mL) but showed limited efficacy against Staphylococcus aureus, MRSA, and Klebsiella pneumoniae (MIC > 100 μg/mL). Comparative analysis with the previously isolated compound ProcumGastrodin A revealed structure–activity relationships where the higher lipophilicity of PG-A was correlated with enhanced antimicrobial activity. Conclusions: This study establishes 5pHSA as a novel phenolic compound with moderate antibacterial properties. The findings highlight the importance of molecular polarity and structural complexity in determining antimicrobial efficacy, offering valuable insights into the development of phenolic, acid-based antimicrobial agents to address the growing challenge of antimicrobial resistance. Full article