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Caffeine is an ergogenic substance that is consumed globally in many forms. The use of buccally absorbable formulations instead of gastrointestinal uptake has become increasingly popular over the years, especially when accelerated absorption with minimal gastrointestinal stress is desired. This study investigated the impact of five different formulations and administration routes of caffeine on the whole blood concentrations of caffeine, paraxanthine, and theobromine: caffeinated capsules, tablets, shots, pouches, and chewing gums. A uniform dose of caffeine (200 mg) was administered to 16 healthy recreational athletes (26.0 ± 2.1 years) using a randomized crossover design. Samples were taken in the form of dried blood spots at 16 different time points in a 2-hr timeframe after drug administration. The samples were analyzed using a validated liquid chromatography–tandem mass spectrometry method. The results for caffeine showed no significant differences in the overall bioavailability (area under the concentration–time curve), maximal concentration, and time to maximum concentration. However, when analyzing the bioavailability of caffeine in the first 5, 10, and 15 min, the liquid caffeine formulation was superior to other administered forms (p <.05). This indicates that caffeine solubility has a major influence on its absorption rate. In sports, the rate of caffeine absorption must be considered, not only when ingesting anhydrous caffeine, but also when choosing buccal absorption. These findings imply that general guidelines for ergogenic caffeine use should consider the formulation used and, accordingly, the corresponding route of absorption. [ABSTRACT FROM AUTHOR]

Liquid chromatography with mass spectrometry (LC-MS)-based metabolomics detects thousands of molecular features (retention time-m/z pairs) in biological samples per analysis, yet the metabolite annotation rate remains low, with 90% of signals classified as unknowns. To enhance the metabolite annotation rates, researchers employ tandem mass spectral libraries and challenging in silico fragmentation software. Hydrogen/deuterium exchange mass spectrometry (HDX-MS) may offer an additional layer of structural information in untargeted metabolomics, especially for identifying specific unidentified metabolites that are revealed to be statistically significant. Here, we investigate the potential of hydrophilic interaction liquid chromatography (HILIC)-HDX-MS in untargeted metabolomics. Specifically, we evaluate the effectiveness of two approaches using hypothetical targets: the post-column addition of deuterium oxide (D2O) and the on-column HILIC-HDX-MS method. To illustrate the practical application of HILIC-HDX-MS, we apply this methodology using the in silico fragmentation software MS-FINDER to an unknown compound detected in various biological samples, including plasma, serum, tissues, and feces during HILIC-MS profiling, subsequently identified as N1-acetylspermidine.

Ayahuasca is a brew traditionally prepared with a mixture of Psychotria viridis leaves and Banisteriopsis caapi vine and has demonstrated therapeutic properties for depression. Knowledge of the brew composition is important to improve the therapeutic potential and decrease side effects if ayahuasca becomes an option for refractory depression treatment. Ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS) was applied to analyze 126 ayahuasca samples collected from different ayahuasqueiro groups and geographic origins. We were able to observe a differentiation in the metabolite composition of ayahuasca samples prepared by diverse ayahuasqueiro groups. These samples presented different antioxidant effects based on FRAP and ORAC assays. Exploratory statistical analysis demonstrated a trend of separating the samples according to the religious group. The most important identified compounds for differentiation of the brew prepared by distinct religious groups are glycosylated and/or phenolic compounds. The comparison based on the mode of ayahuasca preparation presented more variability than the comparison based on the botanical variety of B. caapi used. We conclude that ayahuasca samples prepared with “caupuri” or “tucunacá” separately exhibited differences in the analysis of L-glutamate and the metabolism of arginine and proline. This suggests that a possible variation in this pathway could explain the occurrence of swollen stem nodes in “caupuri,” one of the B. caapi varieties. [ABSTRACT FROM AUTHOR]

Glycosphingolipids (GSL) are a highly heterogeneous class of lipids representing the majority of the sphingolipid category. GSL are fundamental constituents of cellular membranes that have key roles in various biological processes, such as cellular signaling, recognition, and adhesion. Understanding the structural complexity of GSL is pivotal for unraveling their functional significance in a biological context, specifically their crucial role in the pathophysiology of various diseases. Mass spectrometry (MS) has emerged as a versatile and indispensable tool for the structural elucidation of GSL enabling a deeper understanding of their complex molecular structures and their key roles in cellular dynamics and patholophysiology. Here, we provide a thorough overview of MS techniques tailored for the analysis of GSL, emphasizing their utility in probing GSL intricate structures to advance our understanding of the functional relevance of GSL in health and disease. The application of tandem MS using diverse fragmentation techniques, including novel ion activation methodologies, in studying glycan sequences, linkage positions, and fatty acid composition is extensively discussed. Finally, we address current challenges, such as the detection of low-abundance species and the interpretation of complex spectra, and offer insights into potential solutions and future directions by improving MS instrumentation for enhanced sensitivity and resolution, developing novel ionization techniques, or integrating MS with other analytical approaches for comprehensive GSL characterization. [ABSTRACT FROM AUTHOR]

Bacterial quorum sensing is a chemical language allowing bacteria to interact through the excretion of molecules called autoinducers, like N-acyl-homoserine lactones (AHLs) produced by Gram-negative Burkholderia and Paraburkholderia bacteria known as opportunistic pathogens. The AHLs differ in their acyl-chain length and may be modified by a 3-oxo or 3-hydroxy substituent, or C = C double bonds at different positions. As the bacterial signal specificity depends on all of these chemical features, their structural characterization is essential to have a better understanding of the population regulation and virulence phenomenon. This study aimed at enabling the localization of the C = C double bond on such specialized metabolites while using significantly lower amounts of biological material. The approach is based on LC–MS/MS analyses of bacterial extracts after in-solution derivatization by a photochemical Paternò-Büchi reaction, leading to the formation of an oxetane ring and subsequently to specific fragmentations when performing MS/MS experiments. The in-solution derivatization of AHLs was optimized on several standards, and then the matrix effect of bacterial extracts on the derivatization was assessed. As a proof of concept, the optimized conditions were applied to a bacterial extract enabling the localization of C = C bonds on unsaturated AHLs. [ABSTRACT FROM AUTHOR]

Berries are a rich source of natural antioxidant compounds, which are essential to profile, as they add to their nutritional value. However, the complexity of the matrix and the structural diversity of these compounds pose challenges in extraction and chromatographic separation. By relying on multivariate curve resolution alternating least squares (MCR-ALS) ability to extract components from complex spectral mixtures, our study evaluates the contributions of various extraction techniques to interference, extractability, and quantifying different groups of overlapping compounds using liquid chromatography diode array detection (LC-DAD) data. Additionally, the combination of these methods extends its applicability to evaluate polyphenol degradation in stored berry smoothies, where evolving factor analysis (EFA) is also used to elucidate degradation products. Results indicate that among the extraction techniques, ultrasonication-assisted extraction employing 1% formic acid in methanol demonstrated superior extractability and selectivity for the different phenolic compound groups, compared with both pressurized liquid extraction and centrifugation of the fresh berry smoothie. Employing MCR-ALS on the LC-DAD data enabled reliable estimation of total amounts of compound classes with high spectral overlaps. Degradation studies revealed significant temperature-dependent effects on anthocyanins, with at least 50% degradation after 7 months of storage at room temperature, while refrigeration and freezing maintained fair stability for at least 12 months. The EFA model estimated phenolic derivatives as the main possible degradation products. These findings enhance the reliability of quantifying polyphenolic compounds and understanding their stability during the storage of berry products. [ABSTRACT FROM AUTHOR]

Background: The increasing diversity of psychoactive substances on the unregulated drug market poses significant health, psychological, and social risks to people who use drugs (PWUD). To address these risks, various harm reduction (HR) policies have been implemented, including drug checking services (DCS). Many analytical methods are used for DCS. While qualitative methods (e.g., thin layer chromatography, spectroscopy) are easier to implement, they are not as accurate as quantitative methods (e.g., LC-UV, LC-MS). Some HR programmes have implemented high-performance liquid chromatography coupled with UV detection (LC-UV). This article presents the cross-validation of this quantitative method with a reference liquid chromatography coupled with high resolution mass spectrometry (LC-HRMS) method. Methods: Drug samples were provided by PWUD to a DCS called DrugLab in Marseille, France. The samples were weighed and prepared through dissolution in methanol, followed by ultrasonic bathing. Samples were analysed onsite using LC-UV analysis. They were then subsequently analysed with the reference LC-HRMS method. The LC-UV instrument in DrugLab was calibrated after being purchased; analysis of standard solutions was routinely performed once a month and after maintenance operations. For the LC-HRMS instrument, calibration and quality control procedures followed European Medicines Agency (EMA) guidelines. Statistical analyses were conducted including Spearman correlation tests using IBM® SPSS® Statistics version 20. Results: A total of 102 samples representing different product classes and cutting agents were cross-validated. Differences between both analyses methods for each molecule analysed were ≤ 20%, with significant correlations between both methods' results for most substances. Notably, LC-HRMS provided lower concentration values for cocaine and acetaminophen, whereas it provided higher values for other substances. Correlations were significant for cocaine, ketamine, MDMA, heroin, amphetamine, caffeine, acetaminophen, and levamisole. Conclusions: This study demonstrates that the results provided by DrugLab were accurate and reliable, making LC-UV an adaptable, stable, and suitable analytical method for simple matrices like drugs in a DCS context. However, this cross validation does not guarantee accuracy over time. A proficiency test project in HR laboratories across France is currently under development in order to address potential drifts in LC-UV accuracy. [ABSTRACT FROM AUTHOR]

In this work, a new supramolecular solvent (SUPRAS) was prepared for the first time using hexafluorobutanol (HFB) and farnesol (FO). FO acts as an amphiphile and HFB as a coacervation inducer and density regulator. The method of dispersive liquid‐liquid microextraction followed by high‐performance liquid chromatography, supported by a vortex technique, was established using the prepared SUPRAS for the determination of Sudan dyes in aqueous samples. The extraction parameters, including FO content, HFB content, vortex time, salt addition, and solution pH, were thoroughly investigated and optimized. Under the optimized conditions, the linearity range is 10–750 ng/mL for Sudan I, and 10–1000 ng/mL for Sudan III and Sudan IV, respectively. The limits of detection for Sudan dyes were in the range of 0.8–3.1 ng/mL. The inter‐ and intra‐day relative standard deviations for Sudan dyes were in the range of 1.3%–4.1% and 0.2%–2.6%, respectively. Finally, the proposed method was applied to the determination of Sudan dyes in beverage and river water samples with recoveries ranging from 93.9% to 122.1%. Compared to conventional techniques for the extraction of Sudan dyes in real samples, the proposed method is simpler, faster, and more environmentally friendly. [ABSTRACT FROM AUTHOR]

A method for the determination of phthalates in water is validated. It includes the sorption of hydrophobic components of a sample on a liquid chromatography column and the separation of analyte concentrated by online reversed-phase HPLC: for the quantitative determination of priority phthalates (PPhs) in surface waters at a trace level; qualitative assessment of the ratio of stable carbon isotopes 13C/12C in the PPh composition. It is shown that there is no contribution of PPhs from the laboratory background to the measurement results. The limits of determination (0.15−0.22 μg/L) and the accuracy of the determination (±δ = 10−20%) are found using online reversed-phase HPLC and the UV detection of the analytes. The boundary values for the 13C/12C isotope ratio are substantiated for a qualitative assessment of the results of measuring the Δ13C value in the structure of di(2-ethylhexyl) phthalate and its ingress into waters of Lake Baikal from biogenic and abiogenic sources is revealed. A procedure for determining PPhs by reversed-phase HPLC with online UV detection is tested in the field using a portable liquid chromatograph; the concentration ranges for di-n-butyl phthalate (from <0.15 to 1.6 μg/L) and di(2-ethylhexyl) phthalate (from <0.22 to 1.6 µg/L) in the coastal zone of Lake Baikal are evaluated. [ABSTRACT FROM AUTHOR]

SUMMARY: Plant hormones are chemical signals governing almost every aspect of a plant's life cycle and responses to environmental cues. They are enmeshed within complex signaling networks that can only be deciphered by using broad‐scale analytical methods to capture information about several plant hormone classes simultaneously. Methods used for this purpose are all based on reversed‐phase (RP) liquid chromatography and mass spectrometric detection. Hydrophilic interaction chromatography (HILIC) is an alternative chromatographic method that performs well in analyses of biological samples. We therefore developed and validated a HILIC method for broad‐scale plant hormone analysis including a rapid sample preparation procedure; moreover, derivatization or fractionation is not required. The method enables plant hormone screening focused on polar and moderately polar analytes including cytokinins, auxins, jasmonates, abscisic acid and its metabolites, salicylates, indoleamines (melatonin), and 1‐aminocyclopropane‐1‐carboxylic acid (ACC), for a total of 45 analytes. Importantly, the major pitfalls of ACC analysis have been addressed. Furthermore, HILIC provides orthogonal selectivity to conventional RP methods and displays greater sensitivity, resulting in lower limits of quantification. However, it is less robust, so procedures to increase its reproducibility were established. The method's potential is demonstrated in a case study by employing an approach combining hormonal analysis with phenomics to examine responses of three Arabidopsis ecotypes toward three abiotic stress treatments: salinity, low nutrient availability, and their combination. The case study showcases the value of the simultaneous determination of several plant hormone classes coupled with phenomics data when unraveling processes involving complex cross‐talk under diverse plant‐environment interactions. [ABSTRACT FROM AUTHOR]

Background: Dietary assessment is usually performed through imprecise tools, leading to error-prone associations between diet and health-related outcomes. Metabolomics has been applied in recent years to develop biomarkers of food intake (BFIs) and to study metabolites in the diet-microbiome crosstalk. Candidate BFIs exist to detect intake of meat and to a lesser extent dairy, but validation and further development of BFIs are needed. Here, we aim to identify biomarkers that differentiate between intakes of red meat and dairy, to validate previously reported BFIs for these foods, and to explore the effect of protein-matched meals on selected microbial metabolites. Methods: We conducted a randomized, controlled, cross-over single-meal study comparing a meal with highly fermented yogurt and cheese, and a meal with beef and pork meatballs. Postprandial urine samples from 17 subjects were collected sequentially after each meal up to 24 h and analyzed by untargeted metabolomics through ultra-high-performance-liquid chromatography (UHPLC) coupled via electrospray (ESI) source to a qTOF mass spectrometer. Univariate (repeated measures ANOVA) and multivariate (PLSDA, ML-PLSDA) data analyses were used to select BFIs differentiating the two meals. 3-Indoxyl sulfate, p-cresol sulfate, and several other microbial amino acid catabolites were additionally explored within the urine profiles. Results: Thirty-eight markers of meat and dairy intake were selected and are presented along with their excretion kinetics. Carnosine, taurine, and creatine, as well as hydroxyproline-based dipeptides are confirmed as meat BFIs. For dairy, previously reported metabolites such as acyl-glycines are confirmed, while proline-based dipeptides are reported as novel putative BFIs. Microbial metabolites showed only marginal evidence of differential formation after the two meals. Conclusion: This study allowed us to validate the postprandial kinetics of previously suggested biomarkers of meat and dairy intake and to identify new potential biomarkers. The excretion kinetics are useful to ensure that the collection of urine covers the correct time window in future dietary studies. The BFIs add to the existing body of biomarkers and may further be used in combination to provide a more reliable assessment of meat and dairy intake. Proteolytic microbial metabolites should be further investigated to assess the effect of different protein sources on health. [ABSTRACT FROM AUTHOR]

Rationale: Isopsoralen (ISO), a quality control marker (Q‐marker) in Psoraleae Fructus, is proven to present an obvious anti‐osteoporosis effect. Until now, the metabolism and anti‐osteoporosis mechanisms of ISO have not been fully elucidated, greatly restricting its drug development. Methods: The metabolites of ISO in rats were profiled by using ultrahigh‐performance liquid chromatography coupled with time‐of‐flight mass spectrometry. The potential anti‐osteoporosis mechanism of ISO in vivo was predicted by using network pharmacology. Results: A total of 15 metabolites were characterized in rats after ingestion of ISO (20 mg/kg/day, by gavage), including 2 in plasma, 12 in urine, 6 in feces, 1 in heart, 3 in liver, 1 in spleen, 1 in lung, 3 in kidney, and 2 in brain. The pharmacology network results showed that ISO and its metabolites could regulate AKT1, SRC, NFKB1, EGFR, MAPK3, etc., involved in the prolactin signaling pathway, ErbB signaling pathway, thyroid hormone pathway, and PI3K‐Akt signaling pathway. Conclusions: This is the first time for revealing the in vivo metabolism features and potential anti‐osteoporosis mechanism of ISO by metabolite profiling and network pharmacology, providing data for further verification of pharmacological mechanism. [ABSTRACT FROM AUTHOR]

Nitrosamine compounds pose a significant concern as potential carcinogens, prompting heightened scrutiny from regulatory bodies, particularly regarding their presence in pharmaceuticals. The detection of unacceptable levels of N‐nitrosodiethylamine (NDMA) in ranitidine has led to widespread recalls, driving interest in alternative medications such as nizatidine, which shares a similar pharmacological class and is used to treat various gastrointestinal conditions. Despite fewer reports on NDMA levels in nizatidine, its structural similarity to ranitidine, characterized by a tertiary amine, underscores the potential for NDMA formation. Addressing the analytical challenges associated with nitrosamine detection, this study focuses on developing and validating an ultra‐high pressure liquid chromatography triple quadrupole mass spectrometry (UHPLC–MS/MS) method for quantifying NDMA in both nizatidine active pharmaceutical ingredients and tablet formulations. Method validation adheres to International Council for Harmonisation recommendations, with a demonstrated linear range of 0.25–100 ng/mL for NDMA, exhibiting excellent linearity (regression coefficient >0.999) and efficient recovery rates ranging from 95.98% to 109.57%. The method shows high sensitivity, with limits of detection and quantification of 0.25 and 0.5 ng/mL, respectively. The developed UHPLC–MS/MS method offers a simple, precise, accurate, and selective approach for monitoring NDMA levels in nizatidine formulations available in Australia, promising enhanced sensitivity and specificity with limits of quantification in the ppb and sub‐ppb ranges. [ABSTRACT FROM AUTHOR]

Rationale: 5α‐Androstane‐3α,17β‐diol (3α,5α‐Adiol) is a testosterone‐derived neurosteroid and has anxiolytic and analgesic effects via γ‐aminobutyric acid type A receptors as with the progesterone‐derived neurosteroid, allopregnanolone (AP). Although the psychotropic drug‐evoked changes in the brain AP concentration have been intensively studied, those in the brain 3α,5α‐Adiol concentration remain poorly understood. One of the causes for this is the limited availability of a validated method for quantifying the brain 3α,5α‐Adiol with a sufficient sensitivity and specificity, which is described in this study. Methods: To enhance the detectability of 3α,5α‐Adiol by electrospray ionization‐tandem mass spectrometry (ESI‐MS/MS), derivatization with 4‐dimethylaminobenzoyl azide was employed. The brain sample was purified by solid‐phase extraction and the recovered 3α,5α‐Adiol and the deuterated internal standard were derivatized, then measured by liquid chromatography (LC)/ESI‐MS/MS with selected reaction monitoring. Results: The derivatized 3α,5α‐Adiol, i.e., the bis[(4‐dimethylamino)phenyl carbamate] derivative, provided the intense doubly‐protonated molecule as the precursor ion, then the specific product ion containing the 3α,5α‐Adiol‐skeleton by collision‐induced dissociation. The detectability of 3α,5α‐Adiol was eventually increased 1000‐fold by derivatization. Separation of the derivatized 3α,5α‐Adiol from its stereoisomers and interfering brain components was achieved using a SunShell Biphenyl column with an isopropyl alcohol‐containing mobile phase. A good linearity in the sufficient concentration range, acceptable precision and accuracy, and negligible matrix effect were demonstrated by the validation tests. The animal (rat) study using this method revealed that the brain 3α,5α‐Adiol levels were unaffected by the administration of fluoxetine (FLX) and clozapine (CLZ), in contrast to the significant increase of the AP levels. Conclusion: An LC/ESI‐MS/MS method capable of quantifying 3α,5α‐Adiol in the rat brain using a 20‐mg tissue was developed and validated. The brain levels of 3α,5α‐Adiol had an entirely different behavior from those of AP due to FLX and CLZ administration. [ABSTRACT FROM AUTHOR]

Rationale: Eucommia cortex is the core herb in traditional Chinese medicine preparations for the treatment of osteoporosis. Pinoresinol diglucoside (PDG), the quality control marker and the key pharmacodynamic component in Eucommia cortex, has attracted global attention because of its definite effects on osteoporosis. However, the in vivo metabolic characteristics of PDG and its anti‐osteoporotic mechanism are still unclear, restricting its development and application. Methods: Ultra‐high‐performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry was used to analyze the metabolic characteristics of PDG in rats, and its anti‐osteoporosis targets and mechanism were predicted using network pharmacology. Results: A total of 51 metabolites were identified or tentatively characterized in rats after oral administration of PDG (10 mg/kg/day), including 9 in plasma, 28 in urine, 13 in feces, 10 in liver, 4 in heart, 3 in spleen, 11 in kidneys, and 5 in lungs. Furan‐ring opening, dimethoxylation, glucuronidation, and sulfation were the main metabolic characteristics of PDG in vivo. The potential mechanism of PDG against osteoporosis was predicted using network pharmacology. PDG and its metabolites could regulate BCL2, MARK3, ALB, and IL6, involving PI3K‐Akt signaling pathway, estrogen signaling pathway, and so on. Conclusions: This study was the first to demonstrate the metabolic characteristics of PDG in vivo and its potential anti‐osteoporosis mechanism, providing the data for further pharmacological validation of PDG in the treatment of osteoporosis. [ABSTRACT FROM AUTHOR]

ABSTRACT Complex organic mixtures are found in many areas of research, such as energy, environment, health, planetology, and cultural heritage, to name but a few. However, due to their complex chemical composition, which holds an extensive potential of information at the molecular level, their molecular characterization is challenging. In mass spectrometry, the ionization step is the key step, as it determines which species will be detected. This review presents an overview of the main ionization sources employed to characterize these kinds of samples in Fourier transform mass spectrometry (FT‐MS), namely electrospray (ESI), atmospheric pressure photoionization (APPI), atmospheric pressure chemical ionization (APCI), atmospheric pressure laser ionization (APLI), and (matrix‐assisted) laser desorption ionization ((MA)LDI), and their complementarity in the characterization of complex organic mixtures. First, the ionization techniques are examined in the common direct introduction (DI) usage. Second, these approaches are discussed in the context of coupling chromatographic techniques such as gas chromatography, liquid chromatography, and supercritical fluid chromatography. [ABSTRACT FROM AUTHOR]

Field surveys were conducted on golf courses reporting the inability of imidacloprid to control white grubs (Coleoptera: Scarabaeidae) when applied preventively. Surveys of five sites with significant past imidacloprid use (>10 years) revealed significantly greater white grub populations in rough‐mown turf following imidacloprid treatment than that of adjacent short‐mown fairways. Additionally, spatial analysis by distance indicEs (SADIE) analyses demonstrated a positive correlation between white grub and thatch spatial patterns. To investigate the impact of thatch on imidacloprid efficacy and translocation throughout the turfgrass plant, greenhouse experiments were conducted using turf with differing thatch levels. Imidacloprid concentrations in soil and plant tissues were measured with high‐performance liquid chromatography (HPLC) and compared to values obtained through an enzyme‐linked immunosorbent assay (ELISA) kit to determine if the latter could be a cost‐effective alternative in future studies. ELISA provided reliable estimates of concentrations of imidacloprid compared to HPLC, with only minor discrepancies noted across different types of treatments and assessment timings. Despite finding higher imidacloprid levels in leaf tissues compared to roots and some differences in concentration across thatch treatments, there was no clear pattern showing that thatch thickness significantly affects imidacloprid penetration or accumulation in plant tissues or soil over time. These findings suggest that factors other than thatch thickness may contribute to the observed field failures of imidacloprid in controlling white grubs. Further research is necessary to identify these factors and optimize the use of imidacloprid in turfgrass pest management strategies. [ABSTRACT FROM AUTHOR]

Dental caries is the most widespread form of disease, affecting over 90% of the global population. Amalgam fillings, which have been in use for nearly two centuries, will face an European Union ban by 2025. Although photocomposite fillings are a suitable alternative, health concerns persist because of potential substance release into the oral cavity. This study aimed to evaluate the release of photoinitiator substances and monomers from dental materials into various solvents at different temperatures over 30 days. Cylindrical specimens of the composite resins were submerged in different extraction solutions and incubated at 37 and 50°C. The findings demonstrated that both the extraction solvent and extraction temperature significantly influenced the quantity of leachables (p < 0.05). Furthermore, most leachables were released within the initial days, although some monomers continued to elute for over 30 days. The estimated daily intake was calculated for the worst‐case scenario, confirming the biocompatibility of the composite fillings. The weight loss of dental materials ranged up to 3.5% after 30 days, regardless of the extraction conditions and dental material (p > 0.05). In conclusion, this study contributes to filling several research gaps in the field by addressing the biocompatibility of various dental materials through quantitative and qualitative analyses supported by statistical evaluation. [ABSTRACT FROM AUTHOR]

Background: Dietary assessment is usually performed through imprecise tools, leading to error-prone associations between diet and health-related outcomes. Metabolomics has been applied in recent years to develop biomarkers of food intake (BFIs) and to study metabolites in the diet-microbiome crosstalk. Candidate BFIs exist to detect intake of meat and to a lesser extent dairy, but validation and further development of BFIs are needed. Here, we aim to identify biomarkers that differentiate between intakes of red meat and dairy, to validate previously reported BFIs for these foods, and to explore the effect of proteinmatched meals on selected microbial metabolites. Methods: We conducted a randomized, controlled, cross-over single-meal study comparing a meal with highly fermented yogurt and cheese, and a meal with beef and pork meatballs. Postprandial urine samples from 17 subjects were collected sequentially after each meal up to 24 h and analyzed by untargeted metabolomics through ultra-high-performance-liquid chromatography (UHPLC) coupled via electrospray (ESI) source to a qTOF mass spectrometer. Univariate (repeated measures ANOVA) and multivariate (PLSDA, ML-PLSDA) data analyses were used to select BFIs differentiating the two meals. 3-Indoxyl sulfate, p-cresol sulfate, and several other microbial amino acid catabolites were additionally explored within the urine profiles. Results: Thirty-eight markers of meat and dairy intake were selected and are presented along with their excretion kinetics. Carnosine, taurine, and creatine, as well as hydroxyproline-based dipeptides are confirmed as meat BFIs. For dairy, previously reported metabolites such as acyl-glycines are confirmed, while proline-based dipeptides are reported as novel putative BFIs. Microbial metabolites showed only marginal evidence of differential formation after the two meals. Conclusion: This study allowed us to validate the postprandial kinetics of previously suggested biomarkers of meat and dairy intake and to identify new potential biomarkers. The excretion kinetics are useful to ensure that the collection of urine covers the correct time window in future dietary studies. The BFIs add to the existing body of biomarkers and may further be used in combination to provide a more reliable assessment of meat and dairy intake. Proteolytic microbial metabolites should be further investigated to assess the effect of different protein sources on health. [ABSTRACT FROM AUTHOR]

Introduction: Alzheimer's disease (AD) is the leading cause of dementia, and currently, no effective treatments are available to reverse or halt its progression in clinical practice. Although a plethora of studies have highlighted the benefits of physical exercise in combating AD, elder individuals often have limited exercise capacity. Therefore, mild physical exercise and nutritional interventions represent potential strategies for preventing and mitigating neurodegenerative diseases. Our research, along with other studies, have demonstrated that platycodin D (PD) or its metabolite, platycodigenin, derived from the medicinal plant Platycodon grandiflorus, exerts neuroprotective effects against amyloid b (Ab)-induced neuroinflammation. However, the combined effects of PD and physical exercise on alleviating AD have yet to be explored. The current study aimed to investigate whether combined therapy could synergistically ameliorate memory deficits and AD pathology in 5 FAD mice. Methods: Five-month-old 5 x FAD mice were randomly assigned to four groups, and received either PD (5 mg/kg/day, p.o.), voluntary running, or a combination of both for 47 days. Nest building test, locomotion test, and Morris water maze test were used to evaluate the cognitive function. Immunohistochemical and ELISA analysis was performed to determine Ab build-up, microglia and astrocytes hyperactivation, and survival neurons in the hippocampus and perirhinal cortex. Real-time quantitative PCR analysis was used to assess the polarization of microglia and astrocytes. HPLC analysis was performed to measure monoamine neurotransmitters in the hippocampus. Results and discussion: The combination of PD and voluntary running synergistically restored nest-building behavior, alleviated recognition and spatial memory deficits, and showed superior effects compared to monotherapy. In addition, the PD and voluntary running combination reduced Ab build-up, decreased hyperactivation of microglia and astrocytes in the hippocampus and perirhinal cortex, promoted the polarization of inflammatory M1 microglia and reactive astrocytes toward beneficial phenotypes, and lowered systemic circulating pro-inflammatory cytokines while increasing anti-inflammatory cytokines in 5 FAD mice. Furthermore, combined therapy effectively protected neurons and increased levels of 5-hydroxytryptamine (5-HT) and dopamine (DA) in the hippocampus of 5 FAD mice. In conclusion, the combination of PD and voluntary running holds great potential as a treatment for AD, offering promise for delaying onset or progression of AD. [ABSTRACT FROM AUTHOR]

Volatile compounds in floral nectar may affect plant–pollinator relationships; however, the understanding of the distribution and functions of scented floral nectar is still relatively limited. In this study, we examined the volatile constituents of the scented floral nectar of the black lily Fritillaria camtschatcensis and their potential to attract flower‐visiting flies. In Japan, F. camtschatcensis comprises two varieties, var. camtschatcensis (lowland) and var. keisukei (alpine). The flowers of both varieties secrete large amounts of nectar that is fed on by visiting flies. We investigated the sugar concentration of the nectar using high‐performance liquid chromatography (HPLC) and studied its volatile chemical composition using gas chromatography–mass spectrometry. We conducted a bioassay using a synthetic mixture of nectar volatiles of the lowland variety to test whether flies are attracted to volatile compounds in the nectar scent. HPLC analysis showed that glucose and fructose occur in the nectar of the alpine variety, whereas the lowland variety nectar contained glucose but lacked fructose. Nectar volatile compounds differed substantially between the two varieties; the volatiles of the lowland variety consisted primarily of four aliphatic acids, whereas acetophenone was the main volatile compound in the alpine variety. The bioassay showed that a mixture of three aliphatic acids detected as volatiles of the lowland variety nectar attracts flies, including those that visit the alpine variety flowers such as Calliphoridae. These results suggest that the volatiles of the scented nectar serve as attractants for flower visitors and may have an important role in the pollination of F. camtschatcensis. [ABSTRACT FROM AUTHOR]

In untargeted metabolomics, structures of small molecules are annotated using liquid chromatography-mass spectrometry by leveraging information from the molecular retention time (RT) in the chromatogram and m/z (formerly called ''mass-to-charge ratio'') in the mass spectrum. However, correct identification of metabolites is challenging due to the vast array of small molecules. Therefore, various in silico tools for mass spectrometry peak alignment and compound prediction have been developed; however, the list of candidate compounds remains extensive. Accurate RT prediction is important to exclude false candidates and facilitate metabolite annotation. Recent advancements in artificial intelligence (AI) have led to significant breakthroughs in the use of deep learning models in various fields. Release of a large RT dataset has mitigated the bottlenecks limiting the application of deep learning models, thereby improving their application in RT prediction tasks. This review lists the databases that can be used to expand training datasets and concerns the issue about molecular representation inconsistencies in datasets. It also discusses the application of AI technology for RT prediction, particularly in the 5 years following the release of the METLIN small molecule RT dataset. This review provides a comprehensive overview of the AI applications used for RT prediction, highlighting the progress and remaining challenges. Scientific contribution: This article focuses on the advancements in small molecule retention time prediction in computational metabolomics over the past five years, with a particular emphasis on the application of AI technologies in this field. It reviews the publicly available datasets for small molecule retention time, the molecular representation methods, the AI algorithms applied in recent studies. Furthermore, it discusses the effectiveness of these models in assisting with the annotation of small molecule structures and the challenges that must be addressed to achieve practical applications. [ABSTRACT FROM AUTHOR]

The abuse of tetracycline (TC) has led to serious threats to human health and the environment. Therefore, the rapid and sensitive detection of tetracycline is of particular importance. Herein, we successfully synthesised a bimetallic nanozyme D-Fe/Co-MOF with oxidase activity and established a colourimetric sensor. The complex of Fe2+ in D-Fe/Co-MOF and TC can release hydroxyl radicals (˙OH) and promote the oxidation of TMB. As a result, the colour of the detection system significantly changes, enabling the sensitive colourimetric detection of TC. Compared with the existing Fe/Co-MOF sensor, D-Fe/Co-MOF can effectively reduce the detection error caused by hydrogen peroxide decomposition, improving the accuracy of TC detection. Under the optimal conditions, the absorbance at 652 nm showed a good linear relationship with TC concentration in the range of 0.35–220 μg mL−1. The detection limit was as low as 0.0719 μg mL−1, considerably lower than the national safety standard. The proposed colourimetric sensor was also successfully used for the detection of TC in actual milk samples, and the results were in good agreement with those obtained via liquid chromatography. The proposed strategy for the detection of TC in food is expected to contribute to ensuring food safety and human health. [ABSTRACT FROM AUTHOR]

Reversed-phase liquid chromatography (RPLC) relies on a non-polar stationary phase and a more polar hydro-organic mobile phase, where compound retention is primarily governed by hydrophobicity, with more hydrophobic compounds being retained longer. The introduction of secondary equilibria in the chromatographic system through additives, such as anionic surfactants and ionic liquids (ILs), was proposed to mitigate ionic interactions between positively charged analytes and the anionic free silanol groups in non-endcapped stationary phases, thereby preventing increased retention and peak tailing. Additionally, the combined hydrophobic and ionic interactions between cationic analytes and the ions in these additives was demonstrated to create mixed retention mechanisms that influence retention and selectivity. In this regard, this study investigates aqueous chromatographic systems incorporating both the anionic surfactant sodium dodecyl sulfate (SDS) and the IL 1-hexyl-3-methylimidazolium chloride as mobile phase reagents. This combination of reagents modulates the retention, eliminating the need for organic solvents and resulting in highly sustainable HPLC procedures. The chromatographic behavior was assessed using two different C18 columns (Zorbax Eclipse and XTerra-MS). The strength of solute interactions was estimated by calculating equilibrium parameters and the contributions of hydrophobic and ionic interactions through simple mathematical models. Focusing on the retention of six basic drugs (β-adrenoceptor antagonists), the study highlighted the significant role of ionic interactions. The results demonstrate the feasibility of using aqueous systems combining SDS and an IL for the efficient separation of moderately polar basic compounds without the use of organic solvents. [ABSTRACT FROM AUTHOR]

Diclofenac is one of the most common, commercially available, non-steroidal anti-inflammatory drugs (NSAIDs) in the world, with thousands of tons produced and consumed per year, which creates issues related to its presence in water bodies and the need for its removal from them. Diclofenac forms complexes with cations of each metal, which has inspired a study to check if the formation/precipitation of such complexes can be used for effective diclofenac removal from water solutions. It was found that iron salts, e.g., FeCl3, can be used to remove diclofenac from a water solution in the form a of precipitated complex, provided that a high excess of iron salt was used. It has been observed that the diclofenac initial concentration of 5 × 10−4 M, as a result of FeCl3 addition, after 48 h, decreased by two orders of magnitude. Salts of other metals were found less effective in reducing diclofenac concentration. The iron cation–diclofenac interaction was found to be specific, since the precipitation of other drugs by iron cations has not been observed. In order to quantitively analyze the diclofenac removal (precipitation) by iron and other metal cations, the HPLC/ESI-MS analyses were performed. [ABSTRACT FROM AUTHOR]

Background: Koenigia alpina (All.) T.M.Schust. & Reveal (alpine knotweed) is a perennial herb belonging to the Polygonaceae family. Several studies have examined Polygonaceae species' potential applications as cosmeceutical materials; however, the potential of K. alpina as a cosmeceutical has not yet been studied. Materials and Methods: Hydrogen peroxide (H2O2) and lipopolysaccharide were used to induce an inflammatory response in RAW 264.7 cells. 2,2‐Diphenyl‐1‐picrylhydrazyl (DPPH) radicals and H2O2 were used to evaluate the free‐radical scavenging activity of K. alpina extract and its protective effect against reactive oxygen species (ROS)‐induced cell damage. The whitening, antiaging, and cell proliferation/migration effects of the extracts were evaluated via tyrosinase inhibition, collagenase/elastase inhibition, and wound healing assays, respectively. The anti‐inflammatory effect was confirmed by evaluating nitric oxide (NO) production in RAW 264.7 cells. High‐performance liquid chromatography (HPLC), UV, and MS/MS were used to determine the main components of the extract and fractions. Results: The ethyl acetate (EA) fraction and its aglycone fraction showed very high free‐radical scavenging activities (47.5 and 47.1 µg/mL, respectively). The extract/fractions also showed significant tyrosinase inhibition (IC50 = 0.38 mg/mL in EA fraction), collagenase inhibition (IC50 = 0.21 mg/mL in EA fraction), and elastase inhibition (IC50 = 0.57 mg/mL in aglycone fraction). NO production in lipopolysaccharide‐induced RAW 264.7 cells was inhibited by the extract/fractions. The extract also promoted the closure of scratch wounds in HaCaT cells. The K. alpina extract/fractions contained cardamonin, quercetin, and quercitrin. Conclusion: K. alpina extracts/fractions showed antioxidant, antiaging, whitening, and anti‐inflammatory activities, suggesting they may have potential as antiaging cosmeceuticals. [ABSTRACT FROM AUTHOR]

Summary: Acute caffeine intake affects brain and cardiovascular physiology, yet the concentration–effect relationships on the electroencephalogram and cardiac autonomic activity during sleep are poorly understood. To tackle this question, we simultaneously quantified the plasma caffeine concentration with ultra‐high‐performance liquid chromatography, as well as the electroencephalogram, heart rate and high‐frequency (0.15–0.4 Hz) spectral power in heart rate variability, representing parasympathetic activity, with standard polysomnography during undisturbed human sleep. Twenty‐one healthy young men in randomized, double‐blind, crossover fashion, ingested 160 mg caffeine or placebo in a delayed, pulsatile‐release caffeine formula at their habitual bedtime, and initiated a 4‐hr sleep opportunity 4.5 hr later. The mean caffeine levels during sleep exhibited high individual variability between 0.2 and 18.4 μmol L−1. Across the first two non‐rapid‐eye‐movement (NREM)–rapid‐eye‐movement sleep cycles, electroencephalogram delta (0.75–2.5 Hz) activity and heart rate were reliably modulated by waking and sleep states. Caffeine dose‐dependently reduced delta activity and heart rate, and increased high‐frequency heart rate variability in NREM sleep when compared with placebo. The average reduction in heart rate equalled 3.24 ± 0.77 beats per minute. Non‐linear statistical models suggest that caffeine levels above ~7.4 μmol L−1 decreased electroencephalogram delta activity, whereas concentrations above ~4.3 μmol L−1 and ~ 4.9 μmol L−1, respectively, reduced heart rate and increased high‐frequency heart rate variability. These findings provide quantitative concentration–effect relationships of caffeine, electroencephalogram delta power and cardiac autonomic activity, and suggest increased parasympathetic activity during sleep after intake of caffeine. [ABSTRACT FROM AUTHOR]

Purpose: DNA methylation is a major epigenetic phenomenon through which diet affects health and disease. This study aimed to determine the epigenetic influence of the traditional Korean diet (K-diet) on global DNA methylation via one-carbon metabolism. Methods: A crossover study was conducted on 52 women. Two diets, a K-diet, high in plant foods and low in calories and animal fat, and a control diet, similar to the diet currently consumed in Korea, were provided to all subjects alternately for 4 weeks with a 4-week washout period. Clinical parameters were measured before and after each dietary intervention. Nutrient intake was calculated by using a computer-aided nutritional analysis program. One-carbon metabolites in the serum and global DNA methylation in peripheral mononuclear cells were determined using ultra-performance liquid chromatography-tandem mass spectrometry. Results: The K-diet group consumed more folate (669.9 ± 6.7 µg vs. 502.7 ± 3.0, p < 0.001), B6, B12, serine, and choline, and less methionine (992.6 ± 63 vs. 1048.3 mg ± 34.1, p < 0.0001) than the control group did. In the K-diet group, the increment of plasma 5-methyltetrahydrofolate (0.08 µg/mL ± 0.11 vs 0.02 ± 0.10, p < 0.009) and decrement of L-homocysteine (− 70.7 ± 85.0 vs − 39.3 ± 69.4, p < 0.0168) were greater than those of the control group. Global DNA methylation was significantly increased in the K-diet group (6.70 ± 3.02% to 9.45 ± 3.69, p < 0.0001) but not in the control group. Conclusions: A K-diet high in one-carbon nutrients can enhance the global DNA methylation status, suggesting an epigenetic mechanism by which the K-diet conveys health effects. Trial registration Korean Clinical Trial Registry (trial number: KCT0005340, 24/08/2020, retrospectively registered). [ABSTRACT FROM AUTHOR]

Sinomenium acutum (Thunb.) Rehd. et Wils is widely used in the treatment of rheumatoid arthritis, with its alkaloid compound sinomenine (SIN) being renowned for its significant anti‐inflammatory properties. However, despite its widespread application, the in vivo anti‐inflammatory mechanisms and metabolic pathways of SIN remain incompletely understood. This study established a rapid and reliable method based on an ultra‐high‐performance liquid chromatography method coupled with Quadrupole‐Exactive Orbitrap mass spectrometry and molecular docking to identify and characterize SIN and 69 metabolites in rat plasma, urine, and feces, revealing primary metabolic pathways of hydroxylation, demethylation, sulfation, and glucuronidation. Molecular docking results revealed that phase I reactions, including dedimethylation, demethylation, dehydrogenation, and dihydroxylation, along with their composite reactions, were pivotal in influencing SIN's in vivo anti‐inflammatory activity. M28, M36, and M59 are potentially the most anti‐inflammatory active metabolites of SIN in vivo. This comprehensive analysis unveils SIN's metabolic pathways, offering insights into its biological processes and suggesting a novel approach for exploring active drug constituents. These findings pave the way for further understanding SIN's anti‐inflammatory mechanisms, contributing significantly to the development of new therapeutic strategies. [ABSTRACT FROM AUTHOR]

Antimicrobial peptides take a specific position in the field of antibiotics (ATBs), however, from a large number of available molecules only a few of them were approved and are used in clinics. These therapeutic modalities play a crucial role in the management of diseases caused by multidrug‐resistant bacterial pathogens and represent the last‐line therapy for bacterial infections. Therefore, there is a demand for a rationale use of such ATBs based on optimization of the dosing strategy to minimize the risk of resistance and ensure the sustainable efficacy of the drug in real clinical practice. Therapeutic drug monitoring, as a measurement of drug concentration in the body fluids or tissues, results in the optimization of the patient´s medication and therapy outcome. This strategy is beneficial and could result in tailored therapy for different types of infection and the prolongation of the use and efficacy of ATBs in hospitals. This review paper provides an actual overview of approved antimicrobial peptides used in clinical practice and covers current trends in their analysis by convenient and advanced methodologies used for their identification and/or quantitation in biological matrices for therapeutic drug monitoring purposes. Special emphasis is given to the methods with perspective clinical outcomes. [ABSTRACT FROM AUTHOR]

A dispersive liquid‐liquid microextraction based on hydrophobic deep eutectic solvent (hDES) was developed for the extraction and quantification of four cinnamic acid derivatives in traditional Chinese medicines coupled with high‐performance liquid chromatography‐ultraviolet detection. In this method, a hDES (tetrabutylammonium chloride‐hexanoic acid, molar ratio of 1:2) was prepared as the extractant. It only took 15 s to handle multiple samples simultaneously by hand‐assisted dispersion. The use of a narrow‐bore tube reduced the amount of the hydrophobic extractant with easier recovery. The approach was influenced by several key parameters, including the composition and consumption of the DES, sample phase pH, salt amount, extraction time, and centrifugation time, all of which had been investigated and optimized. Moreover, the formation of the DES was characterized by Fourier‐transform infrared spectroscopy and differential scanning calorimetry. Under the optimal conditions, enrichment factors of the target analytes ranged from 135 to 220. Satisfactory linearities (r ≥ 0.9977), detection limits (0.2–0.4 ng/mL), precision (<8.5%), and accuracy (recoveries: 90.0%–104.6%) were obtained. The method has been successfully applied to the simultaneous extraction and preconcentration of four cinnamic acid derivatives in Chinese medicinal samples with rapidness, high efficiency, and convenience. [ABSTRACT FROM AUTHOR]

The increasing awareness of environmental issues and the transition to green analytical chemistry (GAC) have gained popularity among academia and industry in recent years. One of the principles of GAC is the reduction and replacement of toxic solvents with more sustainable and environmentally friendly ones. This review gives an overview of the advances in applying green solvents as an alternative to the traditional organic solvents for peptide and protein purification and analysis by liquid chromatography (LC) and capillary electrophoresis (CE) methods. The feasibility of using greener LC and CE methods is demonstrated through several application examples; however, there is still plenty of room for new developments to fully realize their potential and to address existing challenges. Thanks to the tunable properties of designer solvents, such as ionic liquids and deep eutectic solvents, and almost infinite possible mixtures of components for their production, it is possible that some new designer solvents could potentially surpass the traditional harmful solvents in the future. Therefore, future research should focus mainly on developing new solvent combinations and enhancing analytical instruments to be able to effectively work with green solvents. [ABSTRACT FROM AUTHOR]

Background: Prenatal alcohol exposure (PAE) is one of the leading causes of preventable developmental disabilities. A lack of objective screening methods results in an under‐recognition of the phenomenon. Phosphatidylethanol (PEth) is a specific ethanol biomarker that reveals alcohol intake up to several weeks after alcohol use. So far, PEth has mostly been a tool for detecting moderate and heavy drinking. With lower PEth cut‐offs, revealing even minor prenatal alcohol consumption is possible. We aimed to find out if a sensitive method for PEth analysis would give additional information about PAE and to assess the cut‐off value for a positive alcohol result in prenatal screening. Methods: The study was an observational study of 3000 anonymous blood samples collected from the Helsinki University Hospital Diagnostic Center between June and September 2023. The Finnish Red Cross Blood Service received the samples originally for blood group typing and antibody screening as part of the prenatal blood screening program. We developed a sensitive PEth 16:0/18:1 analysis method using ultra‐high‐performance liquid chromatography tandem mass spectrometry (UHPLC–MS/MS) equipment after liquid–liquid extraction of PEth from whole blood. The lower limit of quantification was 1 ng/mL. Results: PEth was ≥2 ng/mL in 5.2% of the cases, ≥8 ng/mL in 2.0%, and ≥20 ng/mL in 1.0%. The detection time of PEth can be several weeks, especially with low PEth concentrations and after heavy alcohol consumption. It remained unknown whether the positive PEth tests resulted from drinking deliberately during pregnancy or before pregnancy recognition. Conclusions: We suggest adding PEth 16:0/18:1 to a routine prenatal blood screening program with a cut‐off of 2 ng/mL—and in positive cases, clinical evaluation and retesting in 2–4 weeks. In clinical settings, information on gestational week and alcohol consumption before pregnancy is relevant and needs to be considered when interpreting low PEth concentrations. [ABSTRACT FROM AUTHOR]

The estimation of relative levels of amino acids is crucial for understanding various biological processes in plants, including photosynthesis, stress tolerance, and the uptake and translocation of nutrients. A wide range of liquid chromatography (LC; HPLC/UHPLC)‐based methods is available for measuring the quantity of amino acids in plants. Additionally, the coupling of LC with mass spectrometry (MS) significantly enhanced the robustness of existing chromatographic methods used for amino acid quantification. However, accurate annotation and integration of mass peaks can be challenging for plant biologists with limited experience in analyzing MS data, especially in studies involving large datasets with multiple treatments and/or replicates. Further, there are instances when the experiment demands an overall view of the amino acids profile rather than focusing on absolute quantification. The present protocol provides a detailed LC–MS method for obtaining a qualitative amino acids profile using MS‐DIAL, a versatile and user‐friendly program for processing MS data. Free amino acids were extracted from the leaves of control and Tomato leaf curl Palampur virus (ToLCPalV)‐infected Nicotiana benthamiana plants. Extracted amino acids were derivatized and separated using UHPLC‐QTOF, with each amino acid subsequently identified by aligning mass data with a custom text library created in MS‐DIAL. Further, MS‐DIAL was employed for internal standard‐based normalization to obtain a qualitative profile of 15 amino acids in control and virus‐infected plants. The outlined method aims to simplify the processing of MS data to quickly assess any modulation in amino acid levels in plants with a higher degree of confidence. [ABSTRACT FROM AUTHOR]

We fabricated anti‐glare (AG) coatings on glass sheets by spraying alkoxide‐derived silica sols and demonstrated that the water‐to‐alkoxide ratio is one of the key factors for improving AG performance and sol stability. We synthesized silica sols using tetraethylorthosilicate (TEOS), water, nitric acid, and denatured ethanol and sprayed them on sheets of chemically strengthened glass. The molar ratios of water to TEOS (r) were 3, 7, and 14. The sol with r = 7 provided a higher arithmetic‐mean height (Sa), smaller autocorrelation length (Sal), and better optical properties (lower gloss, higher haze, and lower sparkle level) than the sol with r = 3. An excessive amount of water at r = 14 yielded a large Sal and a high sparkle level. As the storage time of the sols increased, higher r values caused a more pronounced increase in Sa. Although none of the sols showed noticeable temporal changes during dynamic light scattering measurements, solutions with higher r values exhibited a more remarkable reduction in the retention time during liquid chromatography with a styrene‐divinylbenzene matrix. Hence, an excessive amount of water was thought to cause hydrophilization of the polymerized species during storage. [ABSTRACT FROM AUTHOR]

Depression is a mental illness that affects patients' behavior, and it impacts approximately 264 million people globally. Tetracyclic antidepressants (TeCAs) are one class of medication that is available for the treatment of depression. These medications work by modifying hormones such as serotonin, norepinephrine, and dopamine. TeCAs, such as setiptiline, amoxapine, mianserin, maprotiline, and mirtazapine, are four ring‐based compounds that assist in preventing the brain from reabsorbing the neurotransmitters norepinephrine and serotonin. Each of these medications interacts with adrenergic (α1 and α2) and serotonin (5HT1 and 5HT2) receptors independently. Using biological samples (plasma, blood, and urine) and pharmaceutical formulations, this review focuses on providing a complete overview of the various analytical conditions maintained for the medications in the above class and their metabolites. Major analytical methods such as mass spectrometry, gas chromatography, and high‐performance liquid chromatography are used to quantify and determine the drugs. This review provides a thorough understanding of impurity identification, pharmacokinetic and stability evaluations, and structural degradation quantification. It provides valuable and reliable information for research, enhancing their understanding of the subject matter. [ABSTRACT FROM AUTHOR]

A sensitive analytical procedure for simultaneous extraction and determination of bisphenol A and alkyl phenols, namely, 4‐sec‐butylphenol, 4‐tert‐butylphenol, and 4‐tert‐amylphenol from aqueous samples with metal–organic framework (MOF)‐based dispersive micro‐solid‐phase extraction (D‐µSPE) and high‐performance liquid chromatography (HPLC) technique is developed. Sample contaminants were preconcentrated with amino‐functionalized aluminum MOF and later eluted with acetonitrile. The reconstituted sample was subjected to HPLC analysis. Various procedural parameters related to D‐µSPE were optimized. Under optimized preconcentration and chromatographic conditions, calibration curves with excellent linearity (R2 > 0.9986) in the working range of 0.25–100 ng mL−1 were prepared. Limit of detection (S/N = 3) for every analyte within the range of 0.020–0.022 ng mL−1 was obtained. Analyte's recovery 91.16%–97.01% (RSD = 1.02–3.01) for intraday and 89.86%–95.83% (RSD = 1.15–3.13) for inter‐day analysis was obtained from real water samples. [ABSTRACT FROM AUTHOR]

The quality by design enabled the development of cost‐effective, simple, precise, and rapid Reversed phase‐ high‐performance liquid chromatography techniques for determining ritonavir (RIT) and darunavir (DAR) in the tablet dosage form. Systematic method optimization was performed through central composite design by altering the flow rate and composition of the organic phase in the mobile phase as the critical method parameters for evaluating the necessary analytical attributes, namely, the tailing factor, theoretical plate count, and resolution. The optimal separation was achieved on a column with C18 in nature and dimensions of (250 mm length × 4.6 mm id × 5 µm particle size) using a mobile phase consisting of acetonitrile and water (75:25 v/v) at a flow rate of 0.9 mL/min. Detection was carried out at 247 nm. The retention time of DAR and RIT was 2.939 and 3.537 min, respectively, as per International Council for Harmonization (ICH) guidelines. The developed method was useful for the determination of bulk drug and formulations. [ABSTRACT FROM AUTHOR]

Ezetimibe (EZE) is a dyslipidemic agent used to treat hyperlipidemia along with statins and diet changes. To ascertain the drug's degradation profile, stress tests were conducted on it in accordance with International Council for Harmonization recommendations. An ultrahigh‐performance liquid chromatography–mass spectrometry method was developed and validated for the identification and quantification of EZE and its degradants. Using preparative high‐performance liquid chromatography, all impurities were isolated, and their structures were characterized thoroughly using advanced spectral techniques. The drug was relatively stable in basic, peroxide, photolytic, and thermal conditions; however, five degradants were observed in acid degradation. Among the five degradants, three degradation products eluted as Peak‐1, Peak‐2, and Peak‐3 which were found to be novel impurities that were not reported previously. However, the remaining two impurities were identified as Peak‐4 and Peak‐5, despite the insufficient information available. The present study has focused on the isolation of these five acid degradation products and the structural confirmation of these degradants by highly efficient spectral techniques. Moreover, the possible degradation mechanism of the azetidinone ring in the presence of acid has been explained, which might be helpful in determining the quality and purity of EZE and similar pharmaceutical compounds. [ABSTRACT FROM AUTHOR]

An innovative, simple, economical, and sensitive reversed phase–high performance liquid chromatography (RP–HPLC) chromatographic method for simultaneous analysis of erythromycin (ERY) and adapalene (ADP) in bulk and pharmaceutical nanoformulation was developed by analytical quality‐by‐design (AQbD) avenue. According to published research, there is no strategy that integrates RP–HPLC with AQbD for estimating ERY and ADP. The analysis was carried out with Box–Behnken design, which reduced trial runs and design points. Acetonitrile: orthophosphoric acid (OPA) (0.1% triethanolamine) in pH 6.2 water was used as the mobile phase. The ratio was set to 35:65 (v/v) at 0.8 mL/min flow rate to detect the analytes at 231 nm. As per the guidelines in International Conference on Harmonization Q1A (R2), the developed approach was validated. ERY and ADP regression coefficients (r2) were found to be 0.9998 and 0.9999, respectively, over 5–25 µg/mL range. Validation parameters comprising linearity, sensitivity, system suitability, precision, robustness, and accuracy were performed. To assess stability, the drugs were subjected to stress conditions (hydrolytic, oxidative, thermal, and photolytic), and drugs were most vulnerable to degrade in alkaline and oxidative conditions. A new technique successfully analyzed novel drug carriers loaded with ERY and ADP. [ABSTRACT FROM AUTHOR]

The efficiency of a staged photocatalytic reactor prototype was evaluated on a semi‐pilot scale with the removal of acetaminophen, for which anatase particles were synthesized by Sol‐Gel and impregnated on rectangular plates of clay. X‐ray diffraction and Energy Dispersive X‐ray Fluorescence patterns show that the final composite is made up of Al2O3 (14 %), SiO2 (41 %), CaO (3 %) TiO2 (34 %), and Fe2O3 (7 %). The impregnation method favors the dispersion of Anatase on the surface of the adsorbent. TiO2‐Anatase/Clay, classified as a macro‐porous solid with H3‐type hysteresis loops by N2 physisorption. Adsorption processes are improved when using TiO2‐Anatase/Clay compared to using TiO2‐Anatase. The external mass transfer has a greater influence on the removal rate. The dimensionless parameters of the Biot number indicate there are no limitations due to the diffusive effect on the interior of the particle. The evaluation of the kinetic data under the Langmuir‐Hinshelwood equation shows a decrease in efficiency as the initial concentration increases. The acetaminophen molecule shows destabilization in the structure of the aromatic ring with a visible decrease in the signals of this functional group evaluated by High‐Performance Liquid Chromatography and Raman Spectroscopy. [ABSTRACT FROM AUTHOR]

Background: Although several studies have suggested a potential positive association between serum vitamin D levels and muscle strength in older adults, it remains unclear whether this relationship is sex-dependent. Aim: To evaluate the association between serum 25 hydroxyvitamin D [25(OH)D] levels and muscle strength in older adults and to assess whether this association is dependent on sex. Methods: This cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) conducted between 2001 and 2002. A total of 1173 individuals aged 50–85 years (630 men and 543 women) were included in the analysis. The peak isokinetic force of the knee extensor was assessed using a kinetic communicator isokinetic dynamometer. Serum 25(OH)D levels were measured using the standardized liquid chromatography-tandem mass spectrometry method. Linear regression analyses were conducted to estimate coefficients and 95% confidence intervals for muscle strength across tertiles of serum vitamin D levels, adjusting for potential confounders. Results: Tertiles of serum vitamin D were positively associated with muscle strength in older men (p-trend = 0.007), whereas no association was observed in older women (p-trend = 0.140) or in the total sample (men and women together; p-trend = 0.139). Conclusion: Serum vitamin D levels were positively associated with muscle strength specifically in older men, whereas no association was observed in older women. These results suggest that the relationship between vitamin D and strength may be sex-dependent. [ABSTRACT FROM AUTHOR]

A comprehensive LC-MS/MS method, which employs Positive Electrospray Ionization (PEI) and Multiple Reaction Monitoring (MRM) was developed for the simultaneous determination of 35 pesticides belonging to various chemical classes in tomato, brinjal, chili, and okra samples. Extraction was facilitated using a modified QuEChERS method, which allows efficient sample analysis in a single run. Calibration curves for each pesticide exhibited linearity within the concentration range of 0.0025 to 0.1 µg mL−1, with correlation coefficients ranging from 0.993 to 0.999. Mean recoveries at five fortification levels (0.01 to 0.5 µg kg−1) ranged from 80 to 90%, demonstrating satisfactory precision (RSD < 20%). The matrix effects, mitigated through an optimized cleanup process, were observed within the range of 6.42% to 19.52%. The developed method having the limit of quantification of 0.01 mg kg−1 for all 35 pesticides, proved to be highly sensitive and rapid for multi-residue estimation in diverse vegetable samples. Subsequently, the method was used to analyze the market samples from Varanasi, India, which revealed the presence of pesticides like Chlorpyrifos, Chlorantraniliproleand Indoxacarb in tomato, brinjal, chili and okra. Therefore, the method could be considered as a robust tool for monitoring pesticide residues in vegetables, aiding in quality assessment and regulatory compliance in the agriculture sector. [ABSTRACT FROM AUTHOR]

A novel method for the speciation and quantification of polysulfide anions and molecular sulfur in lithium polysulfide solutions in organic solvents is reported. The technique is based on hyphenation of highperformance liquid chromatography (HPLC) and inductively coupled plasma mass spectrometry (ICPMS). A sector-field mass-spectrometer was utilized which made it possible to quantify various sulfur compounds without the need for single component standards and conduct the direct detection of the main isotope of sulfur regardless of interferents such as highly abundant 16O2. Key aspects of separation and sample preparation were considered which allowed complete separation of derivatized polysulfide anions. Gradual adjustment of essential parameters and hardware is described. Variation of plasma settings allowed for obtaining chromatograms with desired analyte peak shapes. The optimized method was applied for the quantification of various lithium polysulfide mixtures in organic solvents showing the accessibility of the corresponding polysulfide distributions with this technique. [ABSTRACT FROM AUTHOR]

Summary: Sphingolipids (SL) are bioactive compounds in milk, dairy products, and infant formula. SL has been found to have different health benefits, such as anti‐inflammatory, antimicrobial, anticancer, and cholesterol‐lowering characteristics. SL requires careful extraction, separation, and identification due to their unique characteristics. This review discusses the importance of extracting, purifying, and analysing SL from milk and dairy products. OE (Organic extraction), SPE (solid‐phase extraction), and SFE (supercritical CO2) techniques, as well as dispersive OE and SPE, are the most common methods. In addition, this review discussed various analytical techniques that can be used to determine and quantify SL classes, including TLC (thin‐layer chromatography), HPLC (high‐performance liquid chromatography), nuclear magnetic resonance spectroscopy, and mass spectrometry. These techniques are crucial for understanding the amounts of SL dairy products and infant formula. The paper also focuses on the different types of SL present in milk, dairy products, and infant formula and their concentrations. SL has the potential to be applied to the development of functional foods, and further research in this area is needed. This article sheds light on the extract, purification, and analysis of SL dairy products and infant formula, as well as their potential health benefits. [ABSTRACT FROM AUTHOR]

BACKGROUND: Besides providing nutritional value, functional foods have potential beneficial effects on health. Consumers worldwide seek food products with added value based on physical and mental well-being. OBJECTIVE: This study aimed to analyze the urinary metabolome of volunteers who consumed a drink based on Costa Rican blackberries (Rubus adenotrichos) to identify the presence of urolithins and other possible bioactive compounds related to beneficial effects on health. METHODS: Fifteen healthy non-smoking male volunteers aged between 19 and 43 years old who consumed 250 ml of blackberry-based drink for breakfast for eight consecutive days were selected. Urine samples were obtained before and after drink consumption, which were submitted to analysis by Ultra-Performance Liquid Chromatography coupled to a Mass Detector (UPLC/ESI-Q-TOF-MS). Subsequently, a metabolomic analysis of the results was performed to identify the presence or absence of urolithins and other bioactive metabolites related to blackberry juice consumption. RESULTS: It was possible to detect high intensity presence of urolithin A (n = 6) and high intensity presence of both urolithin A and B (n = 5) in urine samples in several volunteers. However, finding them was impossible in others, or they were at very low intensities (n = 4). Likewise, it was possible to identify Menth-1-en-4,8 diol glucuronide and 1-O-E-Cinnamoyl-(6-arabinosylglucose) as other compounds related to the consumption of blackberries. CONCLUSIONS: The consumption of Costa Rican blackberries allowed us to demonstrate the presence of three metabotypes within the study population: 40% of strong urolithin A (UAP) producers, 33.3% of both urolithin (A and B) producers (UBP), and 26.7% of weak urolithin A producers (0P). Finally, it is recommended to carry out more research in this regard, considering a greater number of volunteers and including people of both sexes. [ABSTRACT FROM AUTHOR]

Background: Substances that can efficiently enhance skin penetration while exerting no adverse effect are useful for drug and cosmetics formulation. Objective: To investigate the safety and enhance skin penetration efficacy of Putocrin®, a combination containing 2% isosorbide dimethyl ether, 1% pentanediol, and 0.5% inositol. Methods: An in vitro keratinocyte cell assay using 3‐(4,5‐dimethylthiazolyl‐2)‐2,5 diphenyltetrazolium bromide (MTT), and an in vitro EpiKutis® skin study adopted hematoxylin and eosin staining, immunostaining, and liquid chromatography–mass spectrometry (LC–MS) analysis were carried out to investigate the safety of Putocrin®. A pigskin‐Franz cell system experiment applied high‐performance liquid chromatography (HPLC) to compare the skin penetration efficiency of fluorescein isothiocyanate (Fitc)‐labeled tranexamic acid with or without the assistance of Putocrin®. The safety and efficacy of Putocrin® was further evaluated on zebrafish embryos. Results: The MTT assay showed that Putocrin® at concentration ≤2.5% did not significantly affect cell viability. The in vitro EpiKutis® skin study revealed that 2.5% Putocrin® did not affect skin morphology, filaggrin content, ceramide/protein, or fatty acid/protein ratios, but significantly increased loricrin content by 86.00% (p < 0.001). The pigskin‐Franz cell penetration experiment demonstrated that Fitc‐labeled tranexamic acid could barely penetrate the skin (with penetration rate of 1.121%), while Putocrin® significantly enhanced the penetration rate up to 83.983%, which was close to unlabeled tranexamic acid (90.013%). The zebrafish embryo study showed that 2.5% Putocrin® did not exert observable toxicity and obviously assisted the skin penetration of Fitc‐labeled tranexamic acid into fish embryos. These results indicate the strong enhancing skin penetration potency of Putocrin®. Conclusion: This study demonstrated the safety as well as the strong enhancing skin penetration potency of Putocrin® for cosmetics formulation use. [ABSTRACT FROM AUTHOR]

Objective: The prevalence of asthma has gradually increased worldwide in recent years, which has made asthma a global public health problem. However, due to its complexity and heterogeneity, there are a few academic debates on the pathogenic mechanism of asthma. The study of the pathogenesis of asthma through metabolomics has become a new research direction. We aim to uncover the metabolic pathway of children with asthma. Methods: Liquid chromatography (LC)–mass spectrometry (MS)–based metabolomic analysis was conducted to compare urine metabolic profiles between asthmatic children (n = 30) and healthy controls (n = 10). Results: Orthogonal projections to latent structures-discrimination analysis (OPLS-DA) showed that there were significant differences in metabolism between the asthma group and the control group with three different metabolites screened out, including traumatic acid, dodecanedioic acid, and glucobrassicin, and the levels of traumatic acid and dodecanedioic acid in the urine samples of asthmatic children were lower than those of healthy controls therein. Pathway enrichment analysis of differentially abundant metabolites suggested that α-linolenic acid metabolism was an asthma-related pathway. Conclusions: This study suggests that there are significant metabolic differences in the urine of asthmatic children and healthy controls, and α-linolenic acid metabolic pathways may be involved in the pathogenesis of asthma. [ABSTRACT FROM AUTHOR]

Introduction: Dry eye disease (DED) is one of the most prevalent eye conditions worldwide, with artificial tears serving as a primary treatment option. Despite their wide availability on the European market, there is a lack of established classifications based on their physicochemical properties. The aim of our study was therefore (i) to develop an analytical method that measures the concentration and the molecular weight (MW) of the hyaluronic acid (HA) in commercialized products, and (ii) to propose an overview based on their various physicochemical parameters. Methods: The intrinsic viscosity and MW of the HA, as well as osmolarity, pH, rheological profile, and viscosity, were measured or determined. A specific method was developed to measure the average intrinsic viscosity and HA content using a liquid size-exclusion chromatography system. The MW was determined using the Mark–Houwink equation. Results: Thirty-seven products commercialized in Europe were analyzed, with 21 of them containing HA. The HA MW was lowest (300 kDa) for Thealose®, Thealoz Duo® Gel, and Hyabak®, and highest (1300 kDa) for Vismed® Multi, Vismed® Gel, and Neovis® Gel. The pH values varied between 5.94 for Treovis® and 8.06 for Systane® Ultra. Osmolarity ranged between 148 mOsm/L and 325 mOsm/L for Neovis® and Treovis®, respectively. Viscosity was highly variable, ranging from 0.38 mPas·s for Hylolipid® to 337.47 mPas·s for Thealoz® Duo Gel. Finally, rheological profile analysis revealed different shear-thinning behaviors. Conclusion: While the perfect eye drop does not exist, a multitude of options are available to choose from. This study improves our understanding of the major tear substitutes available on the European market based on several physicochemical properties. A better understanding and awareness of these parameters is crucial in order to offer the best treatment for patients with DED. [ABSTRACT FROM AUTHOR]

White-nose syndrome (WNS) is a fungal wildlife disease of bats that has caused precipitous declines in certain Nearctic bat species. A key driver of mortality is premature exhaustion of fat reserves, primarily white adipose tissue (WAT), that bats rely on to meet their metabolic needs during winter. However, the pathophysiological and metabolic effects of WNS have remained ill-defined. To elucidate metabolic mechanisms associated with WNS mortality, we infected a WNS susceptible species, the Little Brown Myotis (Myotis lucifugus), with Pseudogymnoascus destructans (Pd) and collected WAT biopsies for histology and targeted lipidomics. These results were compared to the WNS-resistant Big Brown Bat (Eptesicus fuscus). A similar distribution in broad lipid class was observed in both species, with total WAT primarily consisting of triacylglycerides. Baseline differences in WAT chemical composition between species showed that higher glycerophospholipids (GPs) levels in E. fuscus were dominated by unsaturated or monounsaturated moieties and n-6 (18:2, 20:2, 20:3, 20:4) fatty acids. Conversely, higher GP levels in M. lucifugus WAT were primarily compounds containing n-3 (20:5 and 22:5) fatty acids. Following Pd-infection, we found that perturbation to WAT reserves occurs in M. lucifugus, but not in the resistant E. fuscus. A total of 66 GPs (primarily glycerophosphocholines and glycerophosphoethanolamines) were higher in Pd-infected M. lucifugus, indicating perturbation to the WAT structural component. In addition to changes in lipid chemistry, smaller adipocyte sizes and increased extracellular matrix deposition was observed in Pd-infected M. lucifugus. This is the first study to describe WAT GP composition of bats with different susceptibilities to WNS and highlights that recovery from WNS may require repair from adipose remodeling in addition to replenishing depot fat during spring emergence. [ABSTRACT FROM AUTHOR]