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The computation of entropy in liquids and liquid crystal (LC) phases is a big challenge in statistical physics. In this work, we extend the two-phase thermodynamic model (2PT) to shape anisotropic soft repulsive spherocylinders (SRSs) and report the absolute values of entropy for different LC phases for a range of aspect ratios L/D = 2 − 5. We calculate the density of states for different LC phases and decompose it into contributions arising from translational and rotational degrees of freedom. The translational and rotational modes are further partitioned into diffusive, gas-like, and non-diffusive, solid-like components using a fluidicity factor. In the dilute limit, the entropy values obtained from the 2PT method match exactly those of an ideal rigid rotor. We find that, for a given packing fraction, the magnitude of the total entropy is roughly equal regardless of the different LC phases associated with different aspect ratios. We also compute the excess entropy (for L/D = 5) and compare those with the values obtained using the standard integration approach of MD or Monte Carlo equation of state of SRS. The values obtained using both approaches match very well. The rotational and translational fluidicity factors are further used to determine the phase boundaries of different LC phases. [ABSTRACT FROM AUTHOR]

Rationale: In clinical diagnosis of liver injury, which is an important health concern, serum aminotransferase assays have been the go‐to method used worldwide. However, the measurement of serum enzyme activity has limitations, including inadequate disease specificity and enzyme specificity. Methods: With the high selectivity and specificity provided by nano liquid chromatography–tandem mass spectrometry (LC/MS/MS), this work describes a method for the simultaneous determination of six proteins in liver that can be potentially used as biomarkers for liver injury: glutamic‐pyruvic transaminase 1 (GPT1), glutamic oxaloacetic transaminase 1 (GOT1), methionine adenosyl transferase 1A (MAT1A), glutathione peroxidase 1 (GPX1), cytokeratin 18 (KRT18) and apolipoprotein E (APOE). Results: In validation, the method was shown to have good selectivity and sensitivity (limits of detection at pg/mL level). The analytical method revealed that, compared with normal mice, in carbon tetrachloride‐induced acute liver injury mice, liver MAT1A and GPX1 were significantly lower (p < 0.01 and p < 0.05, respectively), KRT18 was significantly higher (p < 0.05) and APOE and GPT1 were marginally significantly lower (p between 0.05 and 0.1). This is the first work reporting the absolute contents of GPT1, GOT1, MAT1A, GPX1 and KRT18 proteins based on LC/MS. Conclusions: The proposed method provides a basis for establishing more specific diagnostic indicators of liver injury. [ABSTRACT FROM AUTHOR]

Sphingomyelin synthase (SMS) is a sphingolipid-metabolizing enzyme involved in the de novo synthesis of sphingomyelin (SM) from ceramide (Cer). Recent studies have indicated that SMS is a key therapeutic target for metabolic diseases such as fatty liver, type 2 diabetes, atherosclerosis, and colorectal cancer. However, very few SMS inhibitors have been identified because of the limited sensitivity and selectivity of the current fluorescence-based screening assay. In this study, we developed a simple cell-based assay coupled with liquid chromatography/tandem mass spectrometry (LC-MS/MS) to screen for SMS inhibitors. HeLa cells stably expressing SMS1 or SMS2 were used for the screening. A non-fluorescent unnatural C6-Cer was used as a substrate for SMS to produce C6-SM. C6-Cer and C6-SM levels in the cells were monitored and quantified using LC-MS/MS. The activity of ginkgolic acid C15:1 (GA), a known SMS inhibitor, was measured. GA had half-maximal inhibitory concentrations of 5.5 μM and 3.6 μM for SMS1 and SMS2, respectively. To validate these findings, hSMS1 and hSMS2 proteins were optimized for molecular docking studies. In silico analyses were conducted to assess the interaction of GA with SMS1 and SMS2, and its binding affinity. This study offers an analytical approach for screening novel SMS inhibitors and provides in silico support for the experimental findings. [ABSTRACT FROM AUTHOR]

Ultrahigh resolution mass spectrometry hyphenated with liquid chromatography (LC) is an emerging tool to explore the isomeric composition of dissolved organic matter (DOM). However, matrix effects limit the potential for semi-quantitative comparison of DOM molecule abundances across samples. We introduce a post-column infused internal standard (PCI-IS) for reversed-phase LC-FT-ICR MS measurements of DOM and systematically evaluate matrix effects, detector linearity and the precision of mass peak intensities. Matrix effects for model compounds spiked into freshwater DOM samples ranging from a headwater stream to a major river were reduced by 5–10% for PCI-IS corrected mass peak intensities as compared to raw (i.e., untransformed) intensities. A linear regression of PCI-IS corrected DOM mass peak intensities across a typical DOM concentration range (2–15 mg dissolved organic carbon L−1) in original, non-extracted freshwater samples demonstrates excellent linearity of the detector response (r2 > 0.9 for 98% of detected molecular formulas across retention times). Importantly, PCI-IS could compensate for 80% of matrix effects across an environmental gradient of DOM composition from groundwater to surface water. This enabled studying the ionization efficiency of DOM isomers and linking the observed differences to the biogeochemical sources. With PCI-IS original, non-extracted DOM samples can be analysed by LC-FT-ICR MS without carbon load adjustment, and mass peak intensities can be reliably used to semi-quantitatively compare isomer abundances between compositionally similar DOM samples. [ABSTRACT FROM AUTHOR]

Nucleotide sugars (NS) fulfil important roles in all living organisms and in humans, related defects result in severe clinical syndromes. NS can be seen as the "activated" sugars used for biosynthesis of a wide range of glycoconjugates and serve as substrates themselves for the synthesis of other nucleotide sugars. NS analysis is complicated by the presence of multiple stereoisomers without diagnostic transition ions, therefore requiring separation by liquid chromatography. In this paper, we explored weak anion-exchange/reversed-phase chromatography on a hybrid column for the separation of 17 nucleotide sugars that can occur in humans. A robust and reproducible method was established with intra- and inter-day coefficients of variation below 10% and a linear range spanning three orders of magnitude. Application to patient fibroblasts with genetic defects in mannose-1-phosphate guanylyltransferase beta, CDP-l-ribitol pyrophosphorylase A, and UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase showed abnormal levels of guanosine-5′-diphosphate-α-d-mannose (GDP-Man), cytidine-5′-diphosphate-l-ribitol (CDP-ribitol), and cytidine-5′-monophosphate-N-acetyl-β-d-neuraminic acid (CMP-Neu5Ac), respectively, in consonance with expectations based on the diagnosis. In conclusion, a novel, semi-quantitative method was established for the analysis of nucleotide sugars that can be applied to diagnose several genetic glycosylation disorders in fibroblasts and beyond. [ABSTRACT FROM AUTHOR]

The article announces the recipients of the 2023 DAC-EuChemS and Robert Kellner Award Lectures in analytical chemistry. Damià Barceló and Antje J. Baeumner received the awards for their research on microplastics in the aquatic environment and nanomaterials in biosensors, respectively. They discuss their motivations, research focus, and the importance of real-world applications and addressing environmental challenges. The article also covers topics such as biosensors, wearable and intelligent sensors, nucleic acid-based rapid tests, sample preparation strategies, and challenges in environmental analysis. It emphasizes the importance of proteomics in public health and mentions the identification of SARS-CoV-2 proteins in wastewater. The authors also discuss the pressure to publish in academia and offer advice to young scientists, while acknowledging the global impact of Chinese and Indian research. [Extracted from the article]

Rationale: Accurate identification of old rice samples from new ones benefits their market circulation and consumers. However, the current detection methods are still not satisfactory because of their insufficient accuracy or (and) time‐consuming process. Methods: Chelating carboxylic acids (CCAs) were selectively extracted from rice, by stirring with chelating resin and a dilute Na2CO3 solution. The green analytical chemistry guidelines for sample preparation were investigated by using the green chemistry calculator AGREE prep. The extractant was determined by liquid chromatography–mass spectrometry (LC/MS), and statistical analysis of the analytical data was carried out to evaluate the significance of the difference by ChiPlot. Results: The limit of quantitation for the CCAs is in the range of 1 to 50 ng/mL, with a reasonable reproducibility. The CCAs in 23 rice samples were determined within a wide concentration range from 0.03 to 1174 μg/g. Intriguingly, the content of citric acid, malonic acid, α‐ketoglutaric acid and cis‐aconite acid in new rice was each found to be distinctively higher than that in old rice by several times. Even mixtures of old and new rice were found to show much difference in the concentration of citric acid and malic acid. Conclusion: A green analytical method has been developed for the simultaneous determination of CCAs by LC/MS analysis, and the identification of old rice samples from new ones was easily carried out according to their CCA content for the first time. The results indicated that the described method has powerful potential for the accurate identification of old rice samples from new ones. [ABSTRACT FROM AUTHOR]

Phytoremediation is a low-cost and sustainable green technology that uses plants to remove organic and inorganic pollutants from aquatic environments. The aim of this study was to investigate the phytoextraction, phytoaccumulation, and phytotransformation of three fluoroquinolones (FQs) (ciprofloxacin [CIP], enrofloxacin [ENF], and levofloxacin [LVF]) by Japanese radish (Raphanus sativus var. longipinnatus) and duckweed (Lemma minor). Determination of FQs and identification of their transformation products (TPs) were performed using ultra-high-performance liquid chromatography coupled with tandem mass spectrometry (UHPLC–MS/MS). Inter-tissue translocation of FQs in Japanese radish tissues depended on their initial concentration in the medium. CIP (IT = 14.4) and ENF (IT = 17.0) accumulated mainly in radish roots, while LVF in leaves (IT = 230.8) at an initial concentration of 10 µg g−1. CIP (2,104 ng g−1) was detected in the highest concentration, followed by ENF (426.3 ng g−1) and LVF (273.3 ng g−1) in the tissues of both plants. FQs' bioaccumulation factors were significantly higher for duckweed (1.490–18.240) than Japanese radish (0.027–0.103). The removal of FQs from water using duckweed was mainly due to their photolysis and hydrolysis than plant sorption. In the screening, analysis detected 29 FQ TPs. The biotransformation pathways of FQs are described in detail, and the factors that influence their formation are indicated. This study has presented the efficiency of fluoroquinolone (FQ) residues phytoextraction from water by two plant species (water duckweed, Japanese radish). The use of two plant species allowed for a holistic study of the FQ phytoremediation process by determining the efficiency of extraction, tissue distribution, bioaccumulation tendency, and biotransformation. The research gap regarding FQ transformation products in the phytoremediation process and the factors determining their formation has been filled. This study indicated that duckweed can be used with great efficiency to purify water from FQ contamination. [ABSTRACT FROM AUTHOR]

The liver is a highly specialized organ involved in regulating systemic metabolism. Understanding metabolic reprogramming of liver disease is key in discovering clinical biomarkers, which relies on robust tissue biobanks. However, sample collection and storage procedures pose a threat to obtaining reliable results, as metabolic alterations may occur during sample handling. This study aimed to elucidate the impact of pre-analytical delay during liver resection surgery on liver tissue metabolomics. Patients were enrolled for liver resection during which normal tissue was collected and snap-frozen at three timepoints: before transection, after transection, and after analysis in Pathology. Metabolomics analyses were performed using 1H Nuclear Magnetic Resonance (NMR) and Liquid Chromatography-Mass Spectrometry (LC-MS). Time at cryopreservation was the principal variable contributing to differences between liver specimen metabolomes, which superseded even interindividual variability. NMR revealed global changes in the abundance of an array of metabolites, namely a decrease in most metabolites and an increase in β-glucose and lactate. LC-MS revealed that succinate, alanine, glutamine, arginine, leucine, glycerol-3-phosphate, lactate, AMP, glutathione, and NADP were enhanced during cryopreservation delay (all p<0.05), whereas aspartate, iso(citrate), ADP, and ATP, decreased (all p<0.05). Cryopreservation delays occurring during liver tissue biobanking significantly alter an array of metabolites. Indeed, such alterations compromise the integrity of metabolomic data from liver specimens, underlining the importance of standardized protocols for tissue biobanking in hepatology. [ABSTRACT FROM AUTHOR]

Epimedium-Rhizoma drynariae (EP-RD) was a well-known herb commonly used to treat bone diseases in traditional Chinese medicine. Nevertheless, there was incomplete pharmacokinetic behavior, metabolic conversion and chemical characterization of EP-RD in vivo. Therefore, this study aimed to establish metabolic profiles combined with multicomponent pharmacokinetics to reveal the in vivo behavior of EP-RD. Firstly, the diagnostic product ions (DPIs) and neutral losses (NLs) filtering strategy combined with UHPLC-Q-Orbitrap HRMS for the in vitro chemical composition of EP-RD and metabolic profiles of plasma, urine, and feces after oral administration of EP-RD to rats were proposed to comprehensively characterize the 47 chemical compounds and the 97 exogenous in vivo (35 prototypes and 62 metabolites), and possible biotransformation pathways of EP-RD were proposed, which included phase I reactions such as hydrolysis, hydrogenation, dehydrogenation, hydroxylation, dehydroxylation, isomerization, and demethylation and phase II reactions such as glucuronidation, acetylation, methylation, and sulfation. Moreover, a UHPLC-MS/MS quantitative approach was established for the pharmacokinetic analysis of seven active components: magnoflorine, epimedin A, epimedin B, epimedin C, icariin, baohuoside II, and icariin II. Results indicated that the established method was reliably used for the quantitative study of plasma active ingredients after oral administration of EP-RD in rats. Compared to oral EP alone, the increase in area under curves and maximum plasma drug concentration (P < 0.05). This study increased the understanding of the material basis and biotransformation profiles of EP-RD in vivo, which was of great significance in exploring the pharmacological effects of EP-RD. [ABSTRACT FROM AUTHOR]

Stanozolol, a synthetic derivative of testosterone, is one of the common doping drugs among athletes and bodybuilders. It is metabolized to a large extent and metabolites are detected in urine for a longer duration than the parent compound. In this study, a novel dummy molecularly imprinted polymer (DMIP) is developed as a sorbent for solid-phase extraction of stanozolol metabolites from spiked human urine samples. The optimized DMIP is composed of stanozolol as the dummy template, methacrylic acid as the functional monomer, and ethylene glycol dimethacrylate as the cross-linker in a ratio of 1:10:80. The extracted analytes were quantitively determined using a newly developed and validated ultrahigh-performance liquid chromatography tandem mass spectrometry method, where the limits of detection and quantitation were 0.91 and 1.81 ng mL−1, respectively, fulfilling the minimum required performance limit decided on by the World Anti-Doping Agency. The mean percentage extraction recoveries for 3'-hydroxystanozolol, 4β-hydroxystanozolol, and 16β-hydroxystanozolol are 97.80% ± 13.80, 83.16% ± 7.50, and 69.98% ± 2.02, respectively. As such, the developed DMISPE can serve as an efficient cost-effective tool for doping and regulatory agencies for simultaneous clean-up of the stanozolol metabolites prior to their quantification. [ABSTRACT FROM AUTHOR]

Objective Methods Results Conclusions This study focused on the metabolic characteristics of tongue coating in patients with intra‐oral halitosis (IOH) to investigate potential diagnostic biomarkers for IOH.Oral healthy participants were enrolled in this study. Halitosis was evaluated with an organoleptic assessment, a Halimeter®, and an OralChroma™. Tongue coating samples were collected from 18 halitosis patients and 18 healthy controls. Liquid chromatography–mass spectrometry was conducted to reveal the IOH‐related metabolic variations in tongue coating.A total of 2214 metabolites were obtained. Most metabolites were shared between the two groups. A total of 274 upregulated metabolites, such as paramethasone acetate and indole‐3‐acetic acid, and 43 downregulated metabolites, including deoxyadenosine and valyl‐arginine, were detected in the halitosis group. Functional analysis indicated that several metabolic pathways, including arginine biosynthesis, arginine and proline metabolism, histidine metabolism, and lysine degradation were significantly enriched in the IOH group. The least absolute shrinkage and selection operator logistic regression analysis revealed that paramethasone acetate, {1‐[2‐(4‐carbamimidoyl‐benzoylamino)‐propionyl]‐piperidin‐4‐yloxy}‐acetic acid, indole‐3‐acetic acid, and valyl‐arginine were remarkably associated with IOH.This study revealed the metabolites present in tongue coating and identified effective biomarkers, providing essential insights into the prediction, pathogenesis, and diagnosis of IOH. [ABSTRACT FROM AUTHOR]

Objective. Pharmacokinetic parametric images obtained through dynamic fluorescence molecular tomography (DFMT) has ability of capturing dynamic changes in fluorescence concentration, thereby providing three-dimensional metabolic information for applications in biological research and drug development. However, data processing of DFMT is time-consuming, involves a vast amount of data, and the problem itself is ill-posed, which significantly limits the application of pharmacokinetic parametric images reconstruction. In this study, group sparse-based Taylor expansion method is proposed to address these problems. Approach. Firstly, Taylor expansion framework is introduced to reduce time and computational cost. Secondly, group sparsity based on structural prior is introduced to improve reconstruction accuracy. Thirdly, alternating iterative solution based on accelerated gradient descent algorithm is introduced to solve the problem. Main results. Numerical simulation and in vivo experimental results demonstrate that, in comparison to existing methods, the proposed approach significantly enhances reconstruction speed without a degradation of quality, particularly when confronted with background fluorescence interference from other organs. Significance. Our research greatly reduces time and computational cost, providing strong support for real-time monitoring of liver metabolism. [ABSTRACT FROM AUTHOR]

Aggression is a crucial behavior that impacts access to limited resources in different environmental contexts. Androgens synthesized by the gonads promote aggression during the breeding season. However, aggression can be expressed during the non-breeding season, despite low androgen synthesis by the gonads. The brain can also synthesize steroids ("neurosteroids"), including androgens, which might promote aggression during the non-breeding season. Male song sparrows, Melospiza melodia, are territorial year-round and allow the study of seasonal changes in the steroid modulation of aggression. Here, we quantified steroids following a simulated territorial intrusion (STI) for 10 min in wild adult male song sparrows during the breeding and non-breeding seasons. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), we examined 11 steroids: pregnenolone, progesterone, corticosterone, dehydroepiandrosterone, androstenedione, testosterone, 5α-dihydrotestosterone, 17β-estradiol, 17α-estradiol, estriol, and estrone. Steroids were measured in blood and 10 microdissected brain regions that regulate social behavior. In both seasons, STI increased corticosterone in the blood and brain. In the breeding season, STI had no rapid effects on androgens or estrogens. Intriguingly, in the non-breeding season, STI increased testosterone and androstenedione in several behaviorally relevant regions, but not in the blood, where androgens remained non-detectable. Also in the non-breeding season, STI increased progesterone in the blood and specific brain regions. Overall, rapid socially modulated changes in brain steroid levels are more prominent during the non-breeding season. Brain steroid levels vary with season and social context in a region-specific manner and suggest a role for neuroandrogens in aggression during the non-breeding season. [ABSTRACT FROM AUTHOR]

Background: With only one 15 mg primaquine tablet registered by a stringent regulatory authority and marketed, more quality-assured primaquine is needed to meet the demands of malaria elimination. Methods: A classic, two sequence, crossover study, with a 10-day wash out period, of 15 mg of IPCA-produced test primaquine tablets and 15 mg of Sanofi reference primaquine tablets was conducted. Healthy volunteers, aged 18–45 years, without glucose-6-phosphate dehydrogenase deficiency, a baseline haemoglobin ≥ 11 g/dL, creatinine clearance ≥ 70 mL/min/1.73 ms, and body mass index of 18.5–30 kg/m2 were randomized to either test or reference primaquine, administered on an empty stomach with 240 mL of water. Plasma primaquine and carboxyprimaquine concentrations were measured at baseline, then 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 1.75, 2.0, 2.333, 2.667, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 8.0, 10.0, 12.0, 16.0, 24.0, 36.0, 48.0 and 72.0 h by liquid chromatography coupled to tandem mass spectrometry. Primaquine pharmacokinetic profiles were evaluated by non-compartmental analysis and bioequivalence concluded if the 90% confidence intervals (CI) of geometric mean (GM) ratios of test vs. reference formulation for the peak concentrations (Cmax) and area under the drug concentration–time (AUC0–t) were within 80.00 to 125.00%. Results: 47 of 50 volunteers, median age 33 years, completed both dosing rounds and were included in the bioequivalence analysis. For primaquine, GM Cmax values for test and reference formulations were 62.12 vs. 59.63 ng/mL, resulting in a GM ratio (90% CI) of 104.17% (96.92–111.96%); the corresponding GM AUC0–t values were 596.56 vs. 564.09 ngxh/mL, for a GM ratio of 105.76% (99.76–112.08%). Intra-subject coefficient of variation was 20.99% for Cmax and 16.83% for AUC0–t. Median clearances and volumes of distribution were similar between the test and reference products: 24.6 vs. 25.2 L/h, 189.4 vs. 191.0 L, whilst the median half-lives were the same, 5.2 h. Conclusion: IPCA primaquine was bioequivalent to the Sanofi primaquine. This opens the door to prequalification, registration in malaria endemic countries, and programmatic use for malaria elimination. Trial registration The trial registration reference is ISRCTN 54640699 [ABSTRACT FROM AUTHOR]

Mild hypothermia (MH) is an effective measure to alleviate cerebral ischemia–reperfusion (I/R) injury. However, the underlying biological mechanisms remain unclear. This study set out to investigate dynamic changes in urinary proteome due to MH in rats with cerebral I/R injury and explore the neuroprotective mechanisms of MH. A Pulsinelli's four-vessel occlusion (4-VO) rat model was used to mimic global cerebral I/R injury. Liquid chromatography-tandem mass spectrometry (LC–MS/MS) was employed to profile the urinary proteome of rats with/without MH (32 °C) treatment after I/R injury. Representative differentially expressed proteins (DEPs) associated with MH were validated by western blotting in hippocampus. A total of 597 urinary proteins were identified, among which 119 demonstrated significant changes associated with MH. Gene Ontology (GO) annotation of the DEPs revealed that MH significantly enriched in endopeptidase activity, inflammatory response, aging, response to oxidative stress and reactive oxygen species, blood coagulation, and cell adhesion. Notably, changes in 12 DEPs were significantly reversed by MH treatment. Among them, 8 differential urinary proteins were previously reported to be closely associated with brain disease, including NP, FZD1, B2M, EPCR, ATRN, MB, CA1and VPS4A. Two representative proteins (FZD1, B2M) were further validated by western blotting in the hippocampus and the results were shown to be consistent with urinary proteomic analysis. Overall, this study strengthens the idea that urinary proteome can sensitively reflect pathophysiological changes in the brain, and appears to be the first study to explore the neuroprotective effects of MH by urinary proteomic analysis. FZD1 and B2M may be involved in the most fundamental molecular biological mechanisms of MH neuroprotection. In a 4-VO rat model, 119 urinary proteins demonstrated significant changes associated with MH. MH is enriched in endopeptidase activity, inflammatory response, oxidative stress, etc, and significantly reversed changes in 12 DEPs. FZD1 and B2M are thought to be involved in the most fundamental molecular biological mechanisms of MH neuroprotection. [ABSTRACT FROM AUTHOR]

This study aimed on the one hand to clarify the quality, authenticity, safety, and other issues related to products of the anabolic-androgenic steroid methandienone advertised on the Internet and personally imported to Japan and on the other hand to evaluate the use of two portable Raman spectrometers in identifying the active pharmaceutical ingredient (API). The study found that all n = 15 samples purchased from 14 websites were problematic regarding their package, labeling, and/or content. Specifically, one sample (6.7%) was confirmed falsified, twelve samples (80%) were found either to be falsified or unlicensed as pharmaceutical product, and two samples (13.3%) were received without information on the manufacturers' physical address or country of origin, with one sample (6.7%) having no labeling or other accompanying information at all. Both Raman spectrometers were able to identify the API in all samples as confirmed and quantified by ultra-high-performance liquid chromatography–Fourier transform mass spectrometry. Twelve samples contained on average less than 90% of the declared API content. By contacting national regulatory authorities in 44 countries, methandienone products were found to be approved in 1 country and not approved in 21 countries. To prevent health hazards and abuse, measures against the acquisition of anabolic-androgenic steroids from unknown sources are required. Portable Raman spectrometers may be suitable for the non-destructive and quick identification of methandienone in tablets. [ABSTRACT FROM AUTHOR]

Parmotrema perlatum, a lichen belonging to the family Parmeliaceae, is well known for its culinary benefits and aroma used as a condiment in Indian homes is also known as the "black stone flower" or "kalpasi" in India. This research intends to analyze the antioxidant power of the crude extracts using four pH‐based buffers solubilized proteins/peptides and RP‐HPLC fractions of P. perlatum obtained by purification. The proteins that were extracted from the four different buffers were examined using LC‐MS/MS‐based peptide mass fingerprinting. When compared to the other buffers, the 0.1 M of Tris‐HCl buffer pH 8.0 solubilized proteins/peptides had the strongest antioxidant capacity. The sequential purification of the peptide was carried out by using a 3‐kDa cut‐off membrane filter and semipreparative RP‐HPLC. Additionally, the purified fractions of the peptide's antioxidant activity were assessed, and effects were compared with those of the crude and 3 kDa cut‐‐off membrane filtrates. The peptide fractions were sequenced by LC‐MS/MS, which reveals that fraction 2 from RP‐HPLC with the sequence LSWFMVVAP has shown the highest antioxidant potential in comparison with other fractions which can serve as the potential natural antioxidant drug. Further, fraction 2 also showed antibacterial activity against the selected microorganisms. [ABSTRACT FROM AUTHOR]

The contemporary food industry's uses of nanoemulsions (NEs) include food processing, effective nutraceutical delivery, the development of functional chemicals, and the synthesis of natural preservatives, such as phytocompounds. Although cinnamon essential oil (CEO) is widely used in the cosmetic, pharmaceutical, and food industries, it is difficult to add to aqueous‐based food formulations due to its weak stability and poor water solubility. This study describes the formulation of a CEO nanoemulsion (CEONE) by spontaneous emulsification and evaluates its antibacterial and antibiofilm properties against biofilm‐forming Serratia rubidaea BFMO8 isolated from spoiled emperor fish (Lethrinus miniatus). Bacteria causing spoilage in emperor fish were isolated and identified as S. rubidaea using common morphological, cultural, and 16S RNA sequencing methods, and their ability to form biofilms and their susceptibility to CEONE were assessed using biofilm‐specific methods. The spontaneous emulsification formulation of CEONE was accomplished using water and Tween 20 surfactant by manipulating organic and aqueous phase interface properties and controlling particle growth by capping surfactant increases. The best emulsification, with highly stable nano‐size droplets, was accomplished at 750 rpm and a 1:3 ratio concentration. The stable CEONE droplet size, polydispersity index, and zeta potential values were 204.8 nm, 0.115, and −6.05 mV, respectively. FTIR and high‐resolution liquid chromatography‐mass spectrometry (HR‐LCMS) analyses have revealed carboxyl, carbonyl, and phenol‐like primary phytochemical functional groups in CEO and CEONE, which contribute to their antibacterial and antibiofilm properties. [ABSTRACT FROM AUTHOR]

Pesticide application is used in horticulture to reduce plant damage from organisms such as insects and mites. Systemic insecticides are highly efficacious and readily taken up by plant tissues. However, pesticide-treated plants may impose risks to nontarget insects or other organisms within ecosystems. In this study, insecticide residues in nectar, leaves, and flower petals of the horticulturally significant herbaceous annual snapdragon, Antirrhinum majus (Lamiales: Plantaginaceae), were assessed at two locations over several weeks following foliar and drench treatment with five systemic insecticides. Concentrations of the insecticides were determined by liquid chromatography-mass spectrometry. The independent effects Application Method, Application Rate, and Time were statistically significant among all active ingredients in the three matrices in both sites in California (CA) and New Jersey (NJ). The interaction effects were also generally statistically significant in the CA site but less consistently so in the NJ site, dependent on the active ingredient and matrix. Post hoc analyses found the highest residue concentrations in leaves and the lowest in nectar, a trend generally consistent over time regardless of active ingredient for both the CA and NJ sites. The results of this study are discussed in the context of conserving pollinators and other beneficial insects. It is recommended that similar studies should be implemented in different geographical regions and climates, along with multiyear studies for perennial ornamental plants. [ABSTRACT FROM AUTHOR]

Objective: Elsholtzia, as a folk medicine, has been widely used in Miao, Yi, and Lahu nationalities and Tibetan and Chinese medicines in China. We aimed to elucidate the possible mechanisms of action of flavonoids of Elsholtzia densa Benth. (FIE) on apoptosis in HeLa human cervical cancer cells in vitro. Methods: Gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) were used to detect the chemical constituents responsible for the effects of FIE. Network pharmacology was employed to predict the active constituents and their targets to explore the mechanism of action of FIE in treating cervical cancer. Cell cycle and apoptosis were detected by flow cytometry. The intracellular reactive oxygen species (ROS) level and the mitochondrial membrane potential were detected in HeLa cells treated with FIE. RT-PCR assays quantified the expression of apoptosis-related genes. Results and Discusssion: A total of 36 and 109 components were identified by GC-MS and LC-MS, respectively. Six active components, including 5-hydroxy-6,7-dimethoxyflavone, baicalein, cirsimaritin, epicatechin, luteolin, and 5,7-dihydroxy-6-methoxy2-phenylchromen-4-onem, were predicted by network pharmacology. The active components may affect the proliferation and apoptosis of HeLa cells through various cancer pathways, such as NF-kB and PI3K-Akt signaling pathways. FIE significantly inhibited colony formation in HeLa cells. We observed an increase in the total population of apoptotic cells and ROS content in HeLa cells. Further, the mitochondrial membrane potential of HeLa cells was significantly decreased. In HeLa cells, the expression levels of apoptosis-related genes, such as cytochrome C, caspase-3, caspase-9, and bax, were increased, while that of bcl-2 was decreased. Moreover, the ultrastructure of the cells exhibited apoptotic characteristics. Numerous vacuoles and the autophagic structure of the damaged mitochondrial organelles were observed in the cytoplasm of HeLa cells. Conclusions: Flavonoids of Elsholtzia densa Benth. showed clear inhibitory activity in HeLa cells and induced HeLa cell apoptosis through the mitochondrial endogenous apoptotic pathway. [ABSTRACT FROM AUTHOR]

Background Knowledge regarding CNS pharmacokinetics of moxifloxacin is limited, with unknown consequences for patients with meningitis caused by bacteria resistant to beta-lactams or caused by TB. Objective (i) To develop a novel porcine model for continuous investigation of moxifloxacin concentrations within brain extracellular fluid (ECF), CSF and plasma using microdialysis, and (ii) to compare these findings to the pharmacokinetic/pharmacodynamic (PK/PD) target against TB. Methods Six female pigs received an intravenous single dose of moxifloxacin (6 mg/kg) similar to the current oral treatment against TB. Subsequently, moxifloxacin concentrations were determined by microdialysis within five compartments: brain ECF (cortical and subcortical) and CSF (ventricular, cisternal and lumbar) for the following 8 hours. Data were compared to simultaneously obtained plasma samples. Chemical analysis was performed by high pressure liquid chromatography with mass spectrometry. The applied PK/PD target was defined as a maximum drug concentration (C max):MIC ratio >8. Results We present a novel porcine model for continuous in vivo CNS pharmacokinetics for moxifloxacin. C max and AUC0–8h within brain ECF were significantly lower compared to plasma and lumbar CSF, but insignificantly different compared to ventricular and cisternal CSF. Unbound C max:MIC ratio across all investigated compartments ranged from 1.9 to 4.3. Conclusion A single dose of weight-adjusted moxifloxacin administered intravenously did not achieve adequate target site concentrations within the uninflamed porcine brain ECF and CSF to reach the applied TB CNS target. [ABSTRACT FROM AUTHOR]

This study reports a rapid and sensitive reversed‐phase high‐performance liquid chromatography method with ultraviolet detection for the determination of regorafenib (REG) in rat plasma. For the extraction of REG from plasma and the precipitation of plasma proteins, a rapid one‐step precipitation method was performed with methanol. The separation was performed in a methanol‐water mixture (80:20, v:v) mobile phase system with a C18 column and monitored at a wavelength of 258 nm. Nilotinib was used as an internal standard. The linear dynamic range of REG was determined between 5 and 500 ng/mL in standard solution and plasma. The limit of detection of REG from the standard solution was found to be 1.23 ng/mL and the limit of quantitation was 3.73 ng/mL. The limit of detection of REG from plasma was found to be 1.55 ng/mL and the limit of quantitation was 4.70 ng/mL. Regorafenib was administered at 5 mg/kg to 10 healthy male Sprague Dawley rats, and pharmacokinetic results were evaluated. It exhibited a high recovery of 93.82% in plasma. Due to ease of sample preparation, high susceptibility, specificity, and certainty, the described method can be used successfully in the quantification of REG in in‐vivo plasma and in routine analyses in clinical laboratories. [ABSTRACT FROM AUTHOR]

Hedysari Radix is a commonly used traditional Chinese medicine that improves immunity; formononetin, ononin, calycosin, medicarpin, and vanillic acid play an important role in achieving this effect. Herein, a precise and sensitive ultra‐high‐performance‐tandem mass spectrometry method was developed and validated for the determination of five bioactive components that were extracted from plasma using a protein precipitation method. A Waters CORTES C18 (4.6 × 50 mm, 2.7 µm) and a mobile phase composed of methanol and water (containing 0.2% formic acid) were used for the separation. The method was linear within the concentration range of 19.53–625.00 ng/mL for formononetin; 0.01–3.13 ng/mL for ononin; 0.01–3.13 ng/mL for calycosin; 0.16–5.00 ng/mL for medicarpin; and 19.53–625.00 ng/mL for vanillic acid. This method has a lower limit of quantification, is simple, and has a short analysis time and a high degree of separation. The intra‐day precisions and inter‐day precisions of quality control samples were traced to be below 8.58% and 12.64%, respectively. Fidelity intervened from −8.61% to 10%. Finally, the developed method was used to determine the concentrations of the five bioactive components in rat plasma after the administration of rubbing‐ and non‐rubbing processed Hedysari Radix. [ABSTRACT FROM AUTHOR]

The 3,3′‐linked cyclic dinucleotides (CDNs) of adenosine monophosphate (AMP) and guanosine monophosphate (GMP), cyclic di‐AMP (c‐di‐AMP), cyclic di‐GMP (c‐di‐GMP), and c‐GMP–AMP (cGAMP) are second messenger molecules in bacteria that regulate processes, such as biofilm formation, motility, virulence, stress response, and cell wall homeostasis. To analyze the profiles of the three CDNs together with their breakdown and precursor molecules, 5′‐phosphoadenylyl‐(3′ → 5′)adenine (pApA), 5′‐guanylyl‐(3′ → 5′)guanine (pGpG), 5′‐AMP, 3′‐ and 5′‐GMP, adenosine triphosphate (ATP), and GTP, we established an LC–MS/MS‐based approach for semi‐quantification and profiling. Weak anion exchange solid‐phase extraction was employed to improve selectivity and instrumental signal/noise of CDNs as well as pApA and pGpG. CDNs were analyzed using reverse‐phase UHPLC–MS/MS, whereas all other nucleotides were analyzed using hydrophilic interaction chromatography (HILIC)–MS/MS. The instrument limit of quantification ranged from 0.72 (c‐di‐AMP) to 60 nM (ATP and GTP). We applied this method to the analysis of the nine nucleotides in eight bacterial strains and found that the profiles varied widely in terms of both absolute and relative concentrations. Thus, CDN concentrations were generally <1 pmol/mg biomass, and the hydrolysis products, pApA and pGpG, were detected at lower pmol/mg concentrations. The presented method is a relatively simple and straightforward approach to profiling nucleotides with the rationale of comparing their relative levels between populations of bacterial strains. [ABSTRACT FROM AUTHOR]

Numerous studies have suggested that intra‐articular administration of antibiotics following primary revision surgery may be one of the methods for treating prosthetic joint infection (PJI). Vancomycin and meropenem are the two most commonly used antibiotics for local application. Determining the concentrations of vancomycin and meropenem in the serum and synovial fluid of patients with PJI plays a significant role in further optimizing local medication schemes and effectively eradicating biofilm infections. This study aimed to establish a rapid, sensitive, and accurate ultra‐performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method for determining the concentrations of vancomycin and meropenem in human serum and synovial fluid. Serum samples were processed using acetonitrile precipitation of proteins and dichloromethane extraction, while synovial fluid samples were diluted before analysis. Chromatographic separation was achieved in 6 min on a Waters Acquity UPLC BEH C18 column, with the mobile phase consisting of 0.1% formic acid in water (solvent A) and acetonitrile (solvent B). Quantification was carried out using a Waters XEVO TQD triple quadrupole mass spectrometer with an electrospray ionization (ESI) source in positive ion mode. The multiple reaction monitoring (MRM) mode was employed to detect the following quantifier ion transitions: 717.95–99.97 (norvancomycin), 725.90–100.04 (vancomycin), 384.16–67.99 (meropenem). The method validation conformed to the guidelines of the FDA and the Chinese Pharmacopoeia. The method demonstrated good linearity within the range of 0.5–50 μg/ml for serum and 0.5–100 μg/ml for synovial fluid. Selectivity, intra‐day and inter‐day precision and accuracy, extraction recovery, matrix effect, and stability validation results all met the required standards. This method has been successfully applied in the pharmacokinetic/pharmacodynamic (PK/PD) studies of patients with PJI. [ABSTRACT FROM AUTHOR]

Managing ocular microbial infections typically requires pharmacotherapy using antibiotic eye drops, such as moxifloxacin hydrochloride (MFX), combined with an antifungal agent like amphotericin B (AB). We carried out and validated an LC–MS/MS assay to quantify these compounds in rabbit tear fluid in order to look into the pharmacokinetics of these two drugs. We employed a protein precipitation technique for the extraction of drugs under examination. A Waters Symmetry C18 column was used to separate the analytes and internal standard. The composition of the mobile phase was like (A) 0.1% v/v formic acid in water and (B) methanol. The detection of MFX and AB was accomplished through the utilization of positive ion electrospray ionization under multiple reaction monitoring mode. The linearity curves for both analytes exhibited an acceptable trendline across a concentration range of 2.34–300 ng/mL for MFX and 7.81–1000 ng/mL for AB in surrogate rabbit tear fluid. The lower limit of quantitation for MFX was 2.34 ng/mL, while for AB, it was 7.81 ng/mL. The approach was strictly validated, encompassing tests of selectivity, linearity (with r2 > 0.99), precision, accuracy, matrix effects, and stability. Consequently, we employed this method to evaluate the pharmacokinetics profiles of MFX and AB in rabbit tear fluid following single topical doses. [ABSTRACT FROM AUTHOR]

Agricultural intensification has been identified as one of the key causes of global insect biodiversity losses. These losses have been further linked to the widespread use of agrochemicals associated with modern agricultural practices. Many of these chemicals are known to have negative sublethal effects on commercial pollinators, such as managed honeybees and bumblebees, but less is known about the impacts on wild bees. Laboratory‐based studies with commercial pollinators have consistently shown that pesticide exposure can impact bee behavior, with cascading effects on foraging performance, reproductive success, and pollination services. However, these studies typically assess only one chemical, neglecting the complexity of real‐world exposure to multiple agrochemicals and other stressors. In the summer of 2020, we collected wild‐foraging workers of the common eastern bumblebee, Bombus impatiens, from five squash (Cucurbita) agricultural sites (organic and conventional farms), selected to represent a range of agrochemical, including neonicotinoid insecticide, use. For each bee, we measured two behaviors relevant to foraging success and previously shown to be impacted by pesticide exposure: sucrose responsiveness and locomotor activity. Following behavioral testing, we used liquid chromatography–tandem mass spectrometry (LC–MS/MS) chemical analysis to detect and quantify the presence of 92 agrochemicals in each bumblebee. Bees collected from our sites did not vary in pesticide exposure as expected. While we found a limited occurrence of neonicotinoids, two fungicides (azoxystrobin and difenoconazole) were detected at all sites, and the pesticide synergist piperonyl butoxide (PBO) was present in all 123 bees. We found that bumblebees that contained higher levels of PBO were less active, and this effect was stronger for larger bumblebee workers. While PBO is unlikely to be the direct cause of the reduction in bee activity, it could be an indicator of exposure to pyrethroids and/or other insecticides that we were unable to directly quantify, but which PBO is frequently tank‐mixed with during pesticide applications on crops. We did not find a relationship between agrochemical exposure and bumblebee sucrose responsiveness. To our knowledge, this is the first evidence of a sublethal behavioral impact of agrochemical exposure on wild‐foraging bees. [ABSTRACT FROM AUTHOR]

Pharmaceuticals are found in aquatic environments due to their widespread use and environmental persistence. To date, a range of impairments to aquatic organisms has been reported with exposure to pharmaceuticals; however, further comparisons of their impacts across different species on the molecular level are needed. In the present study, the crustacean Daphnia magna and the freshwater fish Japanese medaka, common model organisms in aquatic toxicity, were exposed for 48 h to the common analgesics acetaminophen (ACT), diclofenac (DCF), and ibuprofen (IBU) at sublethal concentrations. A targeted metabolomic‐based approach, using liquid chromatography–tandem mass spectrometry to quantify polar metabolites from individual daphnids and fish was used. Multivariate analyses and metabolite changes identified differences in the metabolite profile for D. magna and medaka, with more metabolic perturbations for D. magna. Pathway analyses uncovered disruptions to pathways associated with protein synthesis and amino acid metabolism with D. magna exposure to all three analgesics. In contrast, medaka exposure resulted in disrupted pathways with DCF only and not ACT and IBU. Overall, the observed perturbations in the biochemistry of both organisms were different and consistent with assessments using other endpoints reporting that D. magna is more sensitive to pollutants than medaka in short‐term studies. Our findings demonstrate that molecular‐level responses to analgesic exposure can reflect observations of other endpoints, such as immobilization and mortality. Thus, environmental metabolomics can be a valuable tool for selecting sentinel species for the biomonitoring of freshwater ecosystems while also uncovering mechanistic information. Environ Toxicol Chem 2024;43:1339–1351. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

• Extracted root protein from resistant and susceptible tobacco genotype at 60 DAI of nematode infection. • 2DE and in-solution digested proteins analyzed by RPLC-MS/MS to identify the unknown proteins. • Comparative proteomics revealed RFK1 and RPP 13 like candidate genes exclusively present in resistant genotype. • Out of 306 proteins, 79 proteins were up-regulated and 51 proteins were down-regulated. • These candidate genes can be exploited for the development to resistant crop against nematode disease. Root knot nematode (RKN) is an obligate endoparasitic pest of many vegetable, fruits, non-food cash crops etc. It causes more economic losses in terms of production and productivity worldwide. A range of management strategies including synthetic nematicides are available which can be harmful to human health, environment, wildlife, beneficial organisms and may induce resistance in plant populations. Therefore, identification of resistant gene is an alternative strategy to improve the crop either through breeding or by transgenic technology. In present investigation, an attempt was made to identify the candidate genes resistant to root knot nematode through proteomics approach. Comparative proteome was executed using RKN resistant ABT-10 and susceptible A-119 genotype. Proteomics was performed on nematode-challenged root tissue using 2D gel electrophoresis, in-solution trypsin digestion, and reverse phase liquid chromatography mass spectrometry. A total of 306 proteins were identified of which 79 proteins were up-regulated, 51 were down-regulated and 176 proteins showed no significant expression in resistant genotype. Out of 51 up-regulated proteins, two genes namely LRR Receptor-Like Serine/Threonine-Protein Kinase RFK1 and Putative Disease Resistance RPP13-Like Protein were identified in RKN resistant genotype. In addition to these two genes, RT-PCR analysis showed that three additional genes—Putative Wall-Associated Receptor Kinase-Like 11, Alpha-mannosidase, and TMV Resistance Protein N-Like gene—had significantly higher gene expression levels in the resistant root sample, exhibiting 14.89, 9.95, and 6.81 fold expression, respectively. The identified candidate genes can be exploited further for development of nematode resistant genotype in vegetables as well as other field crops through transgenic approaches. [ABSTRACT FROM AUTHOR]

Despite being protected by the blood–brain barrier and the blood–cerebrospinal fluid barrier, cerebrospinal fluids can contain contaminants that trigger neurotoxic effects, yet there are few effective methods to analyze metabolites of industrial additives. Here, we established a fast and robust analytical methodology, based on ultra-high performance liquid chromatography interfaced with triple quadrupole mass spectrometry, to quantitatively determine concentrations of metabolites of synthetic antioxidants, organophosphate esters, and phthalate esters in human cerebrospinal fluids. The developed method exhibited highly sensitive and stable instrumental performance, satisfactory recoveries, minimal matrix effects, and trace level detection limits. We identified and quantified thirty industrial additive metabolites in cerebrospinal fluid samples, at 0.58–13 ng/mL total concentrations. [ABSTRACT FROM AUTHOR]

Baijiu (a Chinese liquor), one of the six world-renowned distilled liquors, is popular among consumers, and Saccharomyces cerevisiae plays the most important role. However, the diversity and metabolic differences of S. cerevisiae Baijiu yeasts remain unclear. Here, we first studied S. cerevisiae strains isolated from fermentative agents and then analyzed the environmental tolerance and metabolomic differences among different S. cerevisiae strains. The 29 S. cerevisiae strains were classified into 14 genotypes based on DNA fingerprints. Environmental tolerance analysis revealed differences among yeasts. A total of 88 classes of 854 secondary metabolites were detected via liquid chromatography coupled with tandem mass spectrometry (LC‒MS/MS), 15 of which accounted for more than 1%, and carboxylic acids and their derivatives accounted for the highest percentage (20.73%), followed by benzene and substituted derivatives (12.76%). Both OPLS-DA and differentially abundant metabolite analysis revealed that the metabolites of the 14 S. cerevisiae genotypes were significantly different, and the differentially abundant metabolites l-erythrulose, 5(s)-HpETE, kaempferide, and cellobiose were obtained. Metabolic pathway analysis revealed that the metabolism of glycine, serine, and threonine differed significantly (p < 0.05). These results revealed the phenotypic diversity of industrial Baijiu yeasts and provided additional options for the utilization of S. cerevisiae yeasts in the brewing industry. [ABSTRACT FROM AUTHOR]

Background: Blood-based biomarkers for Alzheimer's disease (AD) are promising to be used in clinical settings. The liver is an important degradation organ of the body. Whether liver function affects the levels of AD biomarkers needs to be studied. Objective: To investigate the associations between liver function and the plasma levels of AD biomarkers. Methods: We conducted an ADNI cohort-based cross-sectional study. Thirteen liver function markers commonly used in clinical settings were analyzed: total protein (TP), albumin (AL), globulin (GL), AL/GL ratio (A/G), total bilirubin (TB), direct bilirubin (DB), indirect bilirubin (IB), alanine aminotransferase (ALT), aspartate aminotransferase (AST), AST/ALT ratio, alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and γ-glutamyltransferase (GGT). Liquid chromatography-tandem mass spectrometry was used to detect the plasma Aβ42 and Aβ40 concentrations. Single Molecule array technique was used to measure the plasma p-tau181 and NfL concentrations. We used linear regression models to analyze the associations between liver function markers and the levels of AD plasma biomarkers. Results: ALP was positively associated with the levels of plasma Aβ42 (β = 0.16, P = 0.018) and Aβ40 (β = 0.21, P = 0.004). LDH was positively associated with the levels of plasma p-tau181 (β = 0.09, P = 0.022). While NfL was correlated with multiple liver function markers, including AL, A/G, ALT, AST/ALT, and LDH. Conclusion: Liver function was associated with the plasma levels of AD biomarkers. It needs to consider the potential influence of liver function on the reference ranges and the interpretation of results for AD biomarkers before clinical use. [ABSTRACT FROM AUTHOR]

Background: In this study, the ultrahigh performance liquid chromatography mass spectrometry/mass spectrometry (UPLC-MS/MS) method was established to test the contents of protocatechuic acid (C7H6O4), salvianolic acid B (C36H30O16), rosmarinic acid (C19H14O3), and cryptotanshinone (C19H20O3) in Qishen Yiqi dripping pills. Materials and Methods: Methanol was chosen as the solvent according to a certain material–liquid ratio as a solution, and the ultrasonic extraction method was used to prepare the sample solution. UPLC-MS/MS was used to complete a quantitative analysis of the contents of Qishen Yiqi dripping pills. Then, the chromatographic conditions were shown as follows. The stationary phase was Agilent ZORBAX SB-C18 (2.1 mm × 100 mm, 1.8 µm), and the mobile phase was acetonitrile–0.1% formic acid water. The column temperature was 40℃, the injection volume was 3 µL, and the flow rate was 0.2 mL⋅min–1. Finally, the determination method was built to test four chemical constituents under the multiple reaction monitoring (MRM) analysis mode. Results: The retention times of protocatechuic acid, salvianolic acid B, rosmarinic acid, and cryptotanshinone were 1.26, 1.32, 1.35, and 6.76 min, respectively. In addition, the concentration ranges of four compounds were 0.25–2.0 µg⋅mL−1, 10.0–50.0 µg⋅mL−1, 5.0–50.0 µg⋅mL−1, and 1.0–10.0 µg⋅mL−1, respectively. And the standard curve showed a good linear relationship in a reasonable range (r 2 ≥ 0.9950). The average recovery rate was from 96% to 124%. The contents of protocatechuic acid, salvianolic acid B, rosmarinic acid, and cryptotanshinone were 0.12%–0.022%, 17%–8.4%, and 6.5%–8.6% in seven batches of Qishen Yiqi dripping pills, which were in the range of 23%–31%. The instrument ran stably, and the method had good accuracy and repeatability (relative standard deviation [RSD] ≤ 3%). Additionally, the test result was stable within 10 h. Conclusion: The contents of the four constituents were different among different batches. The quantitative method was established to determine the four chemical components in Qishen Yiqi dripping pills, which could provide a reference for quality evaluation in vivo. [ABSTRACT FROM AUTHOR]

The detection of nitrosamine impurities, particularly small dialkyl types, which are frequently known to be potent mutagenic carcinogens, in some Sartan group active pharmaceutical ingredients (APIs) and finished drug products caused global regulatory organizations to have concerns. Accordingly, Registration Holders/Applicants, API manufacturers, and their raw material suppliers are required to check the presence of nitrosamines in their products and carry out risk assessments using the quality risk management principles specified in the ICH Q9 guide. In this context, a new LC-MS/MS method has been developed and validated for the simultaneous determination of NDMA, NDEA, NMBA, NDIPA, NEIPA, NDBA, and MeNP nitrosamine compounds in API and finished products as well as in primary packaging materials, one of the risk sources. This validated method was applied to check the nitrosamine content may occur from canister, blister, printed aluminum foil, nasal spray, and eye drop packaging materials as part of the Extractables & Leachables studies arising from interactions between the product and the primary packaging. For the determination and quality control of nitrosamines in sartan group pharmaceutical products and packaging materials, the developed LC-MS/MS analytical method offers highly reliable, fast, high accuracy, good sensitivity and simultaneous detection even at low concentrations. • A new LC-MS/MS method was developed and validated for the detection of nitrosamine impurities in different combined finished products containing sartan group and alu-foil packaging. • Different packaging components were studied within the scope of the Extractables&Leachables study to evaluate the possibility of leaching not only from tablet blisters but also from different pharmaceutical packaging components and ink printed labels. • Validation parameters and acceptance criteria were determined in accordance with USP 〈736〉 mass spectrometry monograph and ICH Q2 (R2) guide. • Packaging components (such as canister, blister, printed aluminum foil, nasal spray, and eye drop packaging materials) were checked in accordance with risk assessment studies carried out in line with the ICH Q9 guide. [ABSTRACT FROM AUTHOR]

Host cell protein (HCP) characterization is a crucial quality parameter for biotherapeutic drug safety and stability. With a liquid chromatography-tandem mass spectrometry (LC-MS/MS) approach, we identified ubiquitin in ultrafiltration/diafiltration (UF/DF) pools of one of our monoclonal antibody (mAb) products. Since ubiquitin occurs physiologically as a post-translational modification (PTM) involved in many cellular functions, we suspected the possibility that if identified as an HCP, it may occur as a covalent modification on the mAb. In fact, in this study we characterized and quantified the ubiquitin modification on the Fc domain of mAbX by data dependent acquisition (DDA) and data independent acquisition (DIA) – MS workflows. Covalent binding and site localization were confirmed by identifying a characteristic diglycine motif on the modified peptide. Initially observed reduced detectability of ubiquitin in samples prepared with native digestion was attributed to impaired digestion and subsequent removal along with the mAb in the precipitation step. Our work has contributed to a better understanding of ubiquitin as an HCP considering its specific features such as occurrence in different topologies and provided insight into how covalent binding to a drug product can affect its identification by MS when native digestion conditions are used. [ABSTRACT FROM AUTHOR]

Porphyromonas gingivalis produces five classes of serine/glycine lipids that are recovered in lipid extracts from periodontitis‐afflicted teeth and diseased gingival tissues, particularly at sites of periodontitis. Because these lipids are recovered in diseased gingival tissues, the purpose of the present study was to evaluate the capacity of cultured human gingival fibroblasts (HGF), keratinocytes, and macrophages to hydrolyze these lipids. We hypothesize that one or more of these cell types will hydrolyze the serine/glycine lipids. The primary aim was to treat these cell types for increasing time in culture with individual highly enriched serine/glycine lipid preparations. At specified times, cells and culture media samples were harvested and extracted for hydrolysis products. The serine/glycine lipids and hydrolysis products were quantified using liquid chromatography–mass spectrometry (LC–MS) and free fatty acids were quantified using gas chromatograph–mass spectrometer. LC–MS analysis used two different mass spectrometric methods. This study revealed that treatment of HGF or macrophage (THP1) cells with lipid (L) 654 resulted in breakdown to L342 and subsequent release into culture medium. However, L654 was converted only to L567 in gingival keratinocytes. By contrast, L1256 was converted to L654 by fibroblasts and macrophages but no further hydrolysis or release into medium was observed. Gingival keratinocytes showed no hydrolysis of L1256 to smaller lipid products but because L1256 was not recovered in these cells, it is not clear what hydrolysis products are produced from L1256. Although primary cultures of gingival fibroblasts and macrophages are capable of hydrolyzing specific serine/glycine lipids, prior analysis of lipid extracts from diseased gingival tissues revealed significantly elevated levels of L1256 in diseased tissues. These results suggest that the hydrolysis of bacterial lipids in gingival tissues may reduce the levels of specific lipids, but the hydrolysis of L1256 is not sufficiently rapid to prevent significant accumulation at periodontal disease sites. [ABSTRACT FROM AUTHOR]

[Display omitted] Ligand functionalization is an effective way to endow Metal-organic frameworks (MOF) with versatility for multiple applications by introducing or displaying substituents without changing the origin framework. In this work, the original MIL-101(Fe) was modified by functional groups, including –NH 2 , –NO 2 , –CH 3 , and -Cl substituents. The Bader charge results and electron localization function (ELF) quantitatively indicated that the functional ligands with different properties can regulate the electron structure of transition-metal centers through interface-charge redistribution. Accompanying the higher adsorption and utilization rate of peroxymonosulfate (PMS), more than 96% of acetaminophen (APAP) was degraded with a mineralization rate of 40.17% under the NH 2 -BDC/PMS system. In terms of mechanism, the amino group not only accelerated the regeneration of Fe(II) via the N C Fe electron-transfer path, but also stimulated the appearance of high-valent Fe species. Meanwhile, the degradation pathways of APAP were proposed by integrating the results of liquid chromatograph-mass spectrometry (LC-MS) and Frontier molecular-orbital theory. Finally, the NH 2 -BDC/PMS system reveals long-term stability, nonselectivity, low biotoxicity as well as secondary pollution for pollutant degradation, which is a considered candidate for further environmental applications. [ABSTRACT FROM AUTHOR]

Background: Dietary intake influences gut microbiome composition, which in turn may be associated with colorectal cancer (CRC). Associations of the gut microbiome with colorectal carcinogenesis may be mediated through bacterially regulated, metabolically active metabolites, including trimethylamine N‐oxide (TMAO) and its precursors, choline, L‐carnitine, and betaine. Methods: Prospective associations of circulating TMAO and its precursors with CRC risk were investigated. TMAO, choline, betaine, and L‐carnitine were measured in baseline serum samples from 761 incident CRC cases and 1:1 individually matched controls in the prospective Prostate, Lung, Colorectal, Ovarian Cancer Screening Trial Cohort using targeted fully quantitative liquid chromatography tandem mass spectrometry panels. Prospective associations of the metabolites with CRC risk, using multivariable conditional logistic regression, were measured. Associations of a priori–selected dietary exposures with the four metabolites were also investigated. Results: TMAO and its precursors were not associated with CRC risk overall, but TMAO and choline were positively associated with higher risk for distal CRC (continuous ORQ90 vs. Q10 [95% CI] = 1.90 [CI, 1.24–2.92; p =.003] and 1.26 [1.17–1.36; p <.0001], respectively). Conversely, choline was inversely associated with rectal cancer (ORQ90 vs. Q10 [95% CI] = 0.77 [0.76–0.79; p <.001]). Red meat, which was previously associated with CRC risk in the Prostate, Lung, Colorectal, Ovarian Cancer Screening Trial Cohort , was positively associated with TMAO (Spearman rho = 0.10; p =.0003). Conclusions: Serum TMAO and choline may be associated with higher risk of distal CRC, and red meat may be positively associated with serum TMAO. These findings provide insight into a potential microbially mediated mechanism underlying CRC etiology. In a prospective study among men and women in the United States, we measured circulating trimethylamine N‐oxide (TMAO), choline, betaine, and L‐carnitine and found that TMAO and choline were positively associated with distal colon cancers. Our findings support future studies into underlying mechanisms and potential TMAO‐targeted interventions to mitigate colorectal cancer risk. [ABSTRACT FROM AUTHOR]

HSP20 emerges as a novel regulator of autophagy in the heart. Nonetheless, the detailed function of HSP20 in the liver and its effect on autophagy remain unknown. Here, we observed that HSP20 expression is increased in liver tissues from mice and patients with metabolic dysfunction–associated steatotic liver disease (MASLD), formerly known as nonalcoholic fatty liver disease. Liver-specific downregulation of HSP20 mitigates hepatic steatosis and insulin resistance in obese mice, while upregulating HSP20 promotes lipid deposition and hepatocyte cell death. Mechanistically, liquid chromatography–tandem mass spectrometry revealed that HSP20 interacts with phosphorylated extracellular regulated protein kinase 2 (ERK2) and prevents its dephosphorylation by dual specificity phosphatase 6, leading to ERK2-mediated repression of autophagy and resulting in aggravated saturated fatty acid (SFA)–triggered hepatocyte death. Importantly, such adverse effects could be ameliorated by ERK inhibitor. Our data reveal a framework of how HSP20 increases susceptibility of SFA-induced liver injury through enhancing ERK2 phosphorylation, which represents a plausible therapeutic intervention to combat MASLD. Article Highlights: HSP20 expression was increased in the livers of mice and people living with metabolic dysfunction–associated steatotic liver disease and positively correlated with steatosis grade and body mass. Upregulating HSP20 sensitizes hepatocytes to lipotoxicity by inhibiting autophagy. HSP20 interacts with phosphorylated extracellular regulated protein kinase 2 and prevents its dephosphorylation by phosphatase dual specificity phosphatase 6, leading to aggravation of saturated fatty acid–triggered hepatocyte death by suppressing autophagy function. The HSP20-extracellular regulated protein kinase 2 pathway is an important target to maintain liver homeostasis in patients with metabolic disorders. [ABSTRACT FROM AUTHOR]

This study aimed to determine whether concentrations of testosterone and its main precursor after menopause, dehydroepiandrosterone (DHEA), are associated with lipoproteins and other lipids in community-dwelling older women. The Sex Hormones in Older Women (SHOW) study was an observational study of 6358 Australian women, aged at least 70 years, with no prior major adverse cardiovascular event who had sex hormones measured by liquid chromatography–tandem mass spectrometry. Associations between hormones and lipids were examined using multilinear regression adjusted for potential confounders. The cross-sectional analyses included 3231 participants, median age 74.0 (interquartile range 71.7–77.9) years. Compared with concentrations in the lowest quartile (Q1), testosterone concentrations in the highest quartiles (Q3 and Q4) were positively associated with high-density lipoprotein cholesterol (HDL-C) (p = 0.002 and p < 0.001, respectively) while Q4 testosterone concentrations were positively associated with total cholesterol (p = 0.038). Q2, Q3 and Q4 testosterone concentrations were significantly inversely associated with triglycerides (TG) (p = 0.024, p = 0.003 and p < 0.001, respectively). For DHEA, Q4 concentrations was positively associated with non-HDL-C (p = 0.024). In older women, higher endogenous testosterone concentrations are significantly associated with higher HDL-C and lower TG, indicating a less atherogenic profile. These findings suggest a neutral, or potentially protective, cardiovascular disease effect of testosterone in older women. [ABSTRACT FROM AUTHOR]

Thiamethoxam, a systemic neonicotinoid insecticide, is widely accepted for use against various chewing and sucking insect pests. In this particular study, the authors examined the dissipation kinetics and metabolism of thiamethoxam in wheat using quick, easy, cheap, effective, rugged and safe (QuEChERS) methodology combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) over two years during the same cropping season. Residues of thiamethoxam and its metabolites in wheat plants were investigated following foliar spray of thiamethoxam at recommended dose (12.5 g a.i. ha−1) and four times the recommended dose (50.0 g a.i. ha−1) at earhead formation stage. Total residues of thiamethoxam and its metabolites in leaves at 0 day (2 h after spray) ranged from 3.69 to 14.36 mg kg−1 for the two doses over the two years. Clothianidin was the only metabolite detected in leaves at 0 day (2 h after spray); however at 7 days after spray nitroguanidine, N-desmethyl-thiamethoxam and 1-methyl-3-nitroguanidine were also detected. Total residues of thiamethoxam and its metabolites in soil at 0 day (2 h after spray) ranged from 0.23 to 0.84 mg kg−1. Thiamethoxam residue in leaves and soil followed first order kinetics with half-life ranging from 9.04 to 15.50 days for the two doses over the two study years. Residues of thiamethoxam and its metabolites in leaves, straw and grain at harvest time for both the doses were below their limit of quantification (0.01 mg kg−1). This information could be helpful for evaluating both regulatory and food safety decisions regarding use of neonicotinoids. [ABSTRACT FROM AUTHOR]

An analytical method that combined large-volume solid-phase (Cleanert-PEP) extraction with ultra-performance liquid chromatography-tandem mass spectrometry (SPE-UPLC-MS/MS) was established for the detection of atrazine, atrazine metabolites, and topramezon residues in environmental water. The results showed that atrazine, its metabolites, and topramezon had a good linear relationship within the linear range of 0.5–50 μg/L, and the linear correlation coefficients of all compounds were r2 ≥ 0.9989. At three spiked levels of 10, 100, and 1000 ng/L, the relative recoveries rate was between 77.1% and 114.1%, with relative standard deviations (RSDs) between 0.9% and 6.8%. The limits of detection (LODs) and limits of quantification (LOQs) of all target compounds were between 0.4 and 3.0 ng/L, and between 1.2 and 10.0 ng/L, respectively. After optimisation, Cleanert-PEP was selected for pretreatment of environmental water, and its elution curve was studied, and the optimal elution volume was 6 mL. The analysis method was applied to surface water bodies around Tai'an City in Shandong Province, China, and none of the target metabolites were detected. This method has the advantages of high sensitivity, good stability, simple operation, and high efficiency. It can be used to quantify topramezon, atrazine, and atrazine metabolite residual in water samples and to investigate their behaviour in environmental water. [ABSTRACT FROM AUTHOR]

Background: It was evidenced that cetylpyridinium‐chloride (CPC) mouthwash could inhibit SARS‐COV‐2 activity and reduce salivary viral load, thus reducing SARS‐CoV‐2 transmission. However, due to insufficient residence time in the oral cavity, CPC‐containing mouthwashes have no prolonged antiviral effect. The duration of action of the CPC buccal tablet is expected to be longer than that of the mouthwash. However, there are currently no reports on the salivary drug concentration of CPC buccal tablets. Objective: The study aimed to investigate the salivary drug concentration of CPC buccal tablets and the antiviral effect of CPC on SARS‐CoV‐2 in vitro. Trial design: This is a single‐dose, single‐arm clinical trial, involving 10 Chinese healthy subjects who received 2‐mg CPC buccal tablet to collect saliva samples and to detect saliva concentration at different timepoints within 2 h (Clinical Trial Registration Number: NCT05802628, Registration Date: April 6, 2023). Materials and methods: CPC concentration in saliva was detected by liquid chromatography tandem mass spectrometry (LC–MS/MS), and pharmacokinetic parameters were calculated based on the non‐compartmental model. With an in vitro antiviral experiment, the activity of CPC buccal tablets against SARS‐CoV‐2 and its cellular toxicity was tested. Results: Drug concentrations in saliva at 15 min, 30 min, 1 h, 1.5 h, and 2 h after administration were 8008.33 (1042.25, 41081.11), 2093.34 (373.15, 5759.83), 1016.58 (378.66, 3480.68), 891.77 (375.66, 6322.07), and 717.43 (197.87, 2152.71) ng/mL. PK parameters of saliva concentration: Cmax = 8008.33 (1042.25, 41081.11) ng/mL, AUC0‐t = 4172.37 (904.42, 13912.61) ng/mL * h, AUC0‐∞ = 6712.85 (1856.77, 19971.12) ng/mL * h, T1/2 = 1.22 (0.59, 2.83) h, Tmax = 0.25 (0.25, 0.25) h. As determined in in vitro experiment, CPC was active on SARS‐CoV‐2 with cytotoxic and inhibitory activity of CC50 = 35.75 μM (≈12155 ng/mL) and EC50 = 7.39 μM (≈2512.6 ng/mL). Conclusions: The comparison between the salivary CPC concentration and EC50/CC50 values from in vitro antiviral experiments suggests that CPC buccal tablets may inhibit SARS‐CoV‐2 activity, and the inhibition may last for approximately 30 min without cytotoxicity. [ABSTRACT FROM AUTHOR]

Introduction: Medical devices (MDs) have a long history of use, and come with regulatory frameworks to ensure user safety. Although topically applied MDs in the form of gels and creams might be used on damaged skin, their composition is often similar to that of cosmetic products applicable to intact skin, especially in terms of preservatives and fragrances. However, unlike cosmetics, these products are not subject to compound‐specific restrictions when used in MDs. Objective: This study aimed to identify and quantify preservatives and fragrances in topically applied MDs and assess their safety towards the Cosmetic Regulation (EC) 1223/2009. Method: Sixty‐nine MDs available on the EU market were subjected to previously validated liquid chromatography tandem mass spectrometry (LC–MS/MS) and gas chromatography–mass spectrometry (GC–MS) methods to identify and quantify occurring preservatives and fragrances. Results: Findings revealed that 32% of the examined MDs did not provide comprehensive ingredient lists, leaving users uninformed about potential risks associated with product use. Furthermore, 30% of these MDs would not meet safety standards for cosmetic products and, most significantly, 13% of the analysed samples contained ingredients that are prohibited in leave‐on cosmetics. Conclusion: Results highlight the pressing demand for more stringent requirements regarding the labelling and composition of MDs to enhance patient safety. Improved regulation and transparency can mitigate potential risks associated with the use of topically applied MDs. [ABSTRACT FROM AUTHOR]

Objective: There is a need to characterize exposures associated with the pathogenesis of systemic lupus erythematosus (SLE). In this pilot study, we explore a hypothesis‐free approach that can measure thousands of exogenous chemicals in blood ("exposome") in patients with SLE and unaffected controls. Methods: This cross‐sectional study analyzed a cohort of patients with prevalent SLE (n = 285) and controls (n = 106). Plasma was analyzed by liquid chromatography–quadrupole time‐of‐flight mass spectrometry (LC‐QTOF/MS). Mass spectrometry features present in at least 25% of all samples were selected for association analysis (n = 2,737). Features were matched to potential chemicals using available databases. Association analysis of abundances of features with SLE status was performed, adjusting for age and sex. We also explored features associated with SLE phenotypes, sociodemographic factors, and current medication use. Results: We found 30 features significantly associated with SLE status (Bonferroni P < 0.05). Of these, seven matched chemical names based on databases. These seven features included phthalate metabolites, a formetanate metabolite, and eugenol. The abundance of acid pesticides differed between patients with SLE and controls (Bonferroni P < 0.05). Two unmatched features were associated with a history of lupus nephritis, and one with anti–double‐stranded DNA antibody production (Bonferroni P < 0.05). Seventeen features varied by self‐reported race and ethnicity, including a polyfluoroalkyl substance (analysis of variance P < 1.69 × 10−5). Eleven features correlated with antimalarials, 6 with mycophenolate mofetil, and 29 with prednisone use. Conclusion: This proof‐of‐concept study demonstrates that LC‐QTOF/MS is a powerful tool that agnostically detects circulating exogenous compounds. These analyses can generate hypotheses of disease‐related exposures for future prospective, longitudinal studies. [ABSTRACT FROM AUTHOR]

Purpose: This study examined the acute and long-term effects of nandrolone decanoate (ND) on fractional synthetic rates (FSR). Methods: Male C57BL/6 mice were randomized into ND (n = 20) or sham (n = 20) groups. ND injections (10 g⋅kg-1⋅wk-1) started at 7 months of ages and continued for 6 wk. Ten animals from each group were randomly separated and examined 1 wk following drug cessation. The remaining animals were examined at 16 months of age. Animals were injected IP with 1.5 mL of deuterated water 24 h before euthanasia. The kidney, liver, heart, gastrocnemius, and soleus were extracted. Samples were analyzed for deuterated alanine enrichment in the bound protein and intracellular fraction by liquid chromatography tandem mass spectrometry to measure estimated FSR (fraction/day (F/D)) of mixed tissue. Results: One-way ANOVA, with treatment and age as fixed factors, indicated that kidney FSR was greater (P = 0.027) in ND (0.41 ± 0.02 F/D) than sham (0.36 ± 0.014F/D) and higher (P = 0.003) in young (0.42 ± 0.2 F/D) than old (0.35 ± 0.01 F/D). Liver and heart FSR values were greater (P ≤ 0.001) in young (0.79 ± 0.06 F/D and 0.13 ± 0.01 F/D, respectively) compared with old (0.40 ± 0.01 F/D and 0.09 ± 0.01 F/D, respectively), but not between ND and sham. Gastrocnemius FSR was (P ≤ 0.001) greater in young (0.06 ± 0.01 F/D) compared with old (0.03 ± 0.002 F/D), and greater (P = 0.006) in ND (0.05 ± 0.01 F/D) compared with sham (0.04 ± 0.003 F/D). Soleus FSR rates were greater (P = 0.050) in young (0.13 ± 0.01 F/D) compared with old (0.11 ± 0.003 F/D), but not between ND (0.12 ± 0.01 F/D) and sham (0.12 ± 0.01 F/D). Old animals who had received ND displayed elevated FSR in the gastrocnemius (P = 0.054) and soleus (P = 0.024). Conclusions: ND use in young adult animals appeared to maintain long-term elevations in FSR in muscle during aging. [ABSTRACT FROM AUTHOR]

Background: This study aimed to assess the response patterns of circulating lipids to exercise and diet interventions in nonalcoholic fatty liver disease (NAFLD). Methods: The 8.6-month four-arm randomized controlled study comprised 115 NAFLD patients with prediabetes who were assigned to aerobic exercise (AEx; n = 29), low-carbohydrate diet (Diet; n = 28), AEx plus low-carbohydrate diet (AED; n = 29), and nonintervention (NI, n = 29) groups. Hepatic fat content (HFC) was quantified by proton magnetic resonance spectroscopy. Serum lipidomic analytes were measured using liquid chromatography-mass spectrometry. Results: After intervention, the total level of phosphatidylcholine (PC) increased significantly in the AEx group (P = 0.043), whereas phosphatidylethanolamine (PE) and triacylglycerol decreased significantly in the AED group (P = 0.046 and P = 0.036, respectively), and phosphatidylserine decreased in the NI group (P = 0.002). Changes of 21 lipid metabolites were significantly associated with changes of HFC, among which half belonged to PC. Most of the molecules related to insulin sensitivity belonged to sphingomyelin (40 of 79). Controlling for the change of visceral fat, the significant associations between lipid metabolites and HFC remained. In addition, baseline serum lipids could predict the response of HFC to exercise and/or diet interventions (PE15:0/18:0 for AED, area under the curve (AUC) = 0.97; PE22:6(4Z,7Z,10Z,13Z,16Z,19Z)/0:0 for AEx, AUC = 0.90; and PC14:1(9Z)/19:1(9Z) for Diet, AUC = 0.92). Conclusions: Changes of lipidome after exercise and/or diet interventions were associated with HFC reductions, which are independent of visceral fat reduction, particularly in metabolites belonging to PC. Importantly, baseline PE could predict the HFC response to exercise, and PC predicted the response to diet. These results indicate that a circulating metabolomics panel can be used to facilitate clinical implementation of lifestyle interventions for NAFLD management. [ABSTRACT FROM AUTHOR]