High-resolution Mass Spectrometry Method Research Articles

Integrated chemical analysis, metabolic profiling, network pharmacology, molecular docking and toxicity prediction to reveal the active ingredients and their safety of raw and prepared rhubarbs in the treatment of gastric ulcers.

Rhubarb, containing raw rhubarb (RR) and two processed products (steamed rhubarb, SR; carbonized rhubarb, CR), is commonly used in high-doses for the treatment of peptic ulcer, especially gastric ulcer (GU). However, their active ingredients, therapeutic targets, and potential mechanism remain unclear. Meanwhile, the safety of these active ingredients is also worth studying. An offline two-dimensional low-pressure liquid chromatography/high-performance liquid chromatography coupled with high resolution mass spectrometry method was applied to identify the chemical constituents of RR, SR, and CR. Then, the plasma and urine samples of rats after oral administration of RR, SR, and CR were studied for metabolite profiling. Based on the analysis of ingredients in vivo, the key active constituents, core therapeutic targets and key signaling pathways of RR, SR, and CR against GU were screened via network pharmacology and molecular docking. Finally, the efficacy and safety of these key active ingredients were evaluated. Totally, 183, 120 and 115 compounds were identified or tentatively characterized from RR, SR and CR, respectively. Meanwhile, 190, 182 and 180 components were identified after oral administration of RR, SR and CR. By network pharmacology and molecular docking, torachrysone, hydroxyemodin, 6-methylrhein, rhein and emodin anthrone might be the predominant effective constituents in RR, SR, and CR with AKT1 and EGFR being their key targets during the treatment of GU. Moreover, EGFR/PI3K/AKT signaling pathway might play a crucial role in the therapeutic mechanism of GU. In silio ADMET predictions categorized 5 compounds as drugs with good oral bioavailability, but these components may induce liver injury. Overall, our results not only clarified the active substances and molecular mechanism for enhancing our understanding about the traditional efficacy, but also pay attention to the clinical safety issues of raw and prepared rhubarbs.

Fatty Acid Profiling in Greek Wines by Liquid Chromatography–High-Resolution Mass Spectrometry (LC-HRMS)

In recent years, the interest in lipids present in wines has increased, because these natural components, even at low or very low concentrations, play an important role in wine evolution and quality and contribute substantially to the taste and mouthfeel of wines. Herein, we present a liquid chromatography–high-resolution mass spectrometry (LC-HRMS) method for the profiling of free fatty acids (FFAs) in wines. The method is fast and allows the simultaneous determination of twenty-seven saturated and unsaturated FFAs in wine samples, avoiding any prior derivatization step. After validation, a variety of white and rose commercial wine samples from the Greek market, either sparkling or non-sparkling, were analyzed by the present method. The majority of wine FFAs are saturated long aliphatic, in particular palmitic (C16:0) and stearic (C18:0) acids, followed by myristic (C14:0) and pentadecanoic (C15:0) acids, while oleic (C18:1), palmitoleic (C16:1) and linoleic (C18:2) acids were quantified among the unsaturated FAs. The medium-chain C6:0 and the unsaturated C16:1 and C18:2 acids were found at higher concentrations in rose wines compared to white.

Validation of an LC-MS/MS Method for Analysis of 58 Drugs of Abuse in Oral Fluid and Method Comparison with an Established LC-HRMS Method.

Liquid chromatography-mass spectrometry (LC-MS) methods for detection of multiple drugs of abuse (DoA) in oral fluid (OF) samples are being implemented in many clinical routine laboratories. Therefore, there is a need to develop new multi-analyte methods with simple sample pre-treatment and short analysis times. The purpose of this work was to validate a method detecting 58 DoA to be used with two different OF sampling kits, the saliva collection system (SCS) from Greiner Bio-One and Quantisal from Immunalysis, using the same sample pretreatment and analytical method. A set of 110 samples collected with the SCS kit was further compared to an LC-HRMS (high resolution mass spectrometry) method in another laboratory. The method was successfully validated, with precision and accuracy of ≤15% and z-scores of <2 for external controls. Using a sensitive LC-MS/MS instrument, the detection limits were <1 µg/L in neat oral fluid. In the comparative study between the LC-MS/MS and LC-HRMS methods using SCS samples, a good agreement was observed. Discrepancies were limited to lower concentration ranges, attributable to differences in cut-off thresholds between the methods. This work contributes to the development of LC-MS multi-analyte methods for OF samples, which are suitable for clinical routine laboratories.

Is aquafaba suitable as a coffee creamer and foam enhancer in instant coffee?

Coffee is commonly consumed with a creamer to reduce the acidic taste, and rich foam is an important feature, particularly in instant coffee. We examined two aquafaba (AF) powders, chickpea and navy bean, as coffee creamers and foam enhancers using physical, chemical, and LC-Q-Orbitrap High-Resolution Mass Spectrometry methods. Chickpea AF powder contained more protein and phenolic content than navy bean AF, while the latter exhibited greater pH, total sugars, saponin, and ash levels. Navy bean AF also showed better flowability and solubility than that of chickpea, hence worse hygroscopicity. Interestingly, adding either AF powder to instant coffee (1 % dw/v) increased protein by 15 % and phenolic content by 4.23 %, but not whiteness. The LC-Q-Orbitrap analysis elucidated their foam properties. Coffee-added chickpea AF foams are better than free coffee and navy bean AF, although the latter's foam is more stable. Thus, AF can enhance coffee froth not act as a whitening agent.

7Method for Detection of Naturally Occurring Toxins in Human Urine Using Liquid Chromatography High Resolution Mass Spectrometry.

Natural toxins present an ongoing risk for human exposure that requires a rapid, accurate diagnosis for proper response. In this study, a qualitative liquid chromatography high resolution mass spectrometry (LC-HRMS) method was developed and validated for the detection of a large, diverse selection of natural toxins. Data-dependent acquisition was performed to identify compounds with an in-house mass spectral library of 129 hazardous toxins that originate from plants, animals, and fungi. All 129 compounds were spiked into human urine, extracted, and evaluated for spectral library matching. Of these, 92 toxins met the quality criteria and underwent validation in urine matrix based on American National Standards Institute (ANSI) guidelines. A generalized workflow for method expansion was developed and enables the rapid addition of relevant compounds to the established method. This LC-HRMS method achieves efficient detection of natural toxins in urine, and the created workflow can rapidly increase compound coverage via method expansion.

Improved quality control of allergen products: Assessing the molecular allergen composition by mass spectrometry.

Natural allergen sources contain a variety of allergens, against which allergic subjects have developed individual sensitization profiles. Ideal allergen products for skin prick testing (SPT) and allergen immunotherapy (AIT) should contain the complete set of allergens of the respective allergen sources to cover all sensitization profiles. However, commercially available allergen products were shown to vary regarding their allergen composition. The qualitative allergen composition of different SPT and AIT products produced from pollen of grasses, birch, mugwort and from house dust mites was assessed by a consistent high-resolution liquid chromatography-coupled tandem mass spectrometry method (LC-MS/MS). All major, mid-tier and most minor allergens were detected in each of the investigated three batches of SPT and AIT products, demonstrating the completeness of the allergen composition and a high degree of batch-to-batch consistency. This is the first study using a single consistent high-resolution LC-MS/MS method to provide solid data on the qualitative allergen composition of SPT and AIT products manufactured from various common allergen sources. The applied method showed high reliability in qualitative batch-to-batch consistency testing and can be performed fast and with high throughput. High-resolution LC-MS/MS is applicable for process development and quality control to ensure market availability of allergen products corresponding to the composition of the respective natural allergen sources.

Identification of novel microcystins in algal extracts by a liquid chromatography–high-resolution mass spectrometry data analysis pipeline

BackgroundMicrocystins are an emergent public health problem. These toxins are secondary metabolites of harmful cyanobacterial blooms, with blooms becoming more prevalent with eutrophication of water. Exposure to microcystins can result in sickness, liver damage, and even death. Over 300 microcystins have been identified to date, with differences in toxicity based on the specific amino acid composition. Because of this diversity in microcystins, as well as the likelihood of detecting as yet undiscovered microcystins, it is vital to establish a methodological workflow to identify any microcystin in a complex sample, regardless of the availability of a reference standard. Additionally, ascribing varying levels of confidence to these identifications is critical to effectively communicate discoveries. MethodsA liquid-chromatography–high-resolution mass spectrometry method was utilized to identify microcystins present in cyanobacterial extracts from a strain of Microcystis aeruginosa and an Aphanizomenon sp. First, microcystin congeners with available standards were identified in the cyanobacterial extract. These known-unknown microcystins were considered to have the highest confidence identifications due to availability of accurate masses, retention times, and library spectra for comparison. Utilizing the spectra of these microcystins, relatively high-abundance diagnostic product-ions were identified and employed to screen the data for additional candidate microcystins. Microcystins without a standard that had an exact mass matching a microcystin published in CyanoMetDB were considered semi-known-unknown microcystins. The remaining microcystins were considered unknown-unknown microcystins. The identities of the microcystins determined herein were additionally supported by product-ion analysis, thiol reactivity, esterification reactions, neutral loss analysis, and literature contextualization. ResultsIn total, utilizing the systematic workflow presented herein, 23 microcystins were identified in the M. aeruginosa culture, including two not published previously: [d-Asp3]MC-LCit and the incompletely identified MC-L(C7H11NO3).

Quantitative assessment of poly- and perfluoroalkyl substances (PFASs) in aqueous film forming foam (AFFF)-impacted soils: a comparison of analytical protocols.

Quantitatively assessing all per- and poly fluoroalkyl substances (PFASs) in an environmental sample, particularly soils impacted by aqueous film forming foams (AFFFs), has proven to be a challenge. To make such an assessment, a comprehensive sample processing procedure and analytical tool must be used. However, doubts remain whether current analytical tools such as high-resolution mass spectrometry (HRMS) with targeted quantitation and semi-quantitative analysis of suspects (Semi-Q HRMS) or total organic fluorine (TOF) are capable of accurately quantifying all non-polymeric PFASs in a sample. Further, current comprehensive soil PFAS HRMS methods are incompatible with TOF, preventing direct comparisons of the approaches. To enable direct comparisons, a soil sample processing procedure that is comprehensive as well as compatible with multiple analytical tools is needed. In this study, we assessed the performance of a previously developed soil PFAS method, EPA Method 1633, and a hybrid solid phase extraction (SPE)-based method for characterizing AFFF-impacted soil composites while maintaining compatibility with multiple analytical tools (i.e., Semi-Q HRMS and TOF). Comparative results for AFFF-impacted soil composites indicate analysis via EPA Method 1633 (as compared to the novel hybrid method) results in maybeup to 75% of the PFAS mass being missed by only analyzing for compounds listed in EPA Method 1633. Simply expanding the EPA Method 1633 analyte list was insufficient to account for the missing mass: up to 69% of the PFAS mass was still missed because of EPA Method 1633's extraction and cleanup bias. Additionally, the novel method developed offers a more comprehensive analysis with minimal reductions to sensitivity when compared to those reported in EPA Method 1633, with limits of quantification ranging from 0.12 to 2.4 ng/g as compared to 0.16-4.0 ng/g, respectively. For these reasons, an alternative hybrid SPE-based method is proposed for comprehensive evaluation of PFASs in AFFF-impacted soils.

Development and Validation of an Analytical Method to Identify and Quantitate Novel Modafinil Analogs in Products Marketed as Dietary Supplements

Modafinil (brand name Provigil®) is a Schedule IV (U.S.) drug used for the treatment of narcolepsy and sleep disorders. It is also known to be used recreationally. Analogs of modafinil, including adrafinil, remain unapproved and/or unscheduled. The lack of scheduling has made these analogs a popular target for recreational use and inclusion in dietary supplements. However, the use of controlled substances (or their analogs) without the care of a physician presents a public health risk. Preliminary nontargeted analyses in our laboratory revealed the presence of adrafinil in several dietary supplements, highlighting the need for an analytical method to identify modafinil analogs in supplements. A liquid chromatography high resolution mass spectrometry (LC-HRMS) method was developed and validated to quantitate modafinil, plus four novel unscheduled modafinil analogs: adrafinil, CRL-40,940, CRL-40,941, and N-methyl-4,4-difluoromodafinil. This method was then applied to four samples of products marketed as dietary supplements collected via undercover purchase. These four products were marketed as nootropics or cognitive enhancers and labeled to contain adrafinil. Adrafinil was found in all four samples. The identification of modafinil analogs in this context is important so that consumers are not, knowingly or unknowingly, consuming these active pharmaceutical ingredients in products marketed as dietary supplements.

Evaluation of Jacalin lectin sorbents for the extraction of the human chorionic gonadotropin glycoforms prior to analysis by nano liquid chromatography-high resolution mass spectrometry

Human chorionic gonadotropin (hCG) is a dimeric, highly glycosylated hormone with a total of 4 N- and 4 O-glycosylation sites in its two subunits, hCGα and hCGβ. Recently, we developed a novel nano liquid chromatography coupled to high resolution mass spectrometry (nanoLC-HRMS) method for the analysis and thus the detection of the intact glycoforms of hCG. Here, a sorbent functionalized with the Jacalin lectin was evaluated in solid-phase extraction (SPE) for its potential to fractionate the hCG glycoforms prior to their nanoLC-HRMS analysis at the intact level, which may facilitate the detection of low-abundance glycoforms and may lead to a more detailed characterization of the hormone glycosylation. A commercial sorbent based on Jacalin immobilized on Sepharose and having a lectin density of 4.5 mg per ml of gel was selected to carry out SPE and its capacity was estimated to be of some tens of μg of hCG per ml of lectin sorbent. Next, the SPE protocol was modified to improve the extraction recoveries. Especially, it was noticed that an extensive pre-conditioning procedure prior to the first use of a cartridge was necessary to remove the residual non-grafted lectins. Indeed, if non-grafted lectins are not eliminated, they may bind a part of hCG glycoforms preventing their retention by the sorbent, leading to low extraction recoveries (around 10 %). With the extensive pre-conditioning procedure, the average extraction recoveries for both hCGα and hCGβ glycoforms were about 50 %, with either recombinant or urinary hCG. Qualitatively, the fractionation of hCG glycoforms between the washing and elution fractions was achieved with the urinary hCG sample by determining the number of glycoforms detected in each fraction. It appears that 12 hCGα glycoforms have a low affinity (detected only in the washing fraction), 1 a low-medium affinity (detected in washing and elution 1 fractions), 16 a medium affinity (detected in washing, elution 1 and 2 fractions), and 12 a high affinity (detected only in elution 1 and 2 fractions). For the hCGβ glycoforms, similarly, 3 have a low affinity and 12 a low-medium affinity. Additionally, the 3 hCGβ glycoforms were detected better. A different behavior was observed with the recombinant hCG sample, which indicates glycosylation differences between the two hCG samples. This shows the potential of lectin-based affinity fractionation before nanoLC-HRMS analysis to better characterize the glycosylation state of hCG at the intact level.

A Versatile Ultra-High-Performance Liquid Chromatography-Full-Scan High-Resolution Mass Spectrometry Method to Quantify Wine Polyphenols.

Polyphenols are responsible for wine colour and astringency, and, as antioxidants, they also have beneficial health properties. In this work, we developed a robust full-scan high-resolution mass spectrometry method for the quantification of 90 phenolic compounds in wine samples (either red, rosé, or white wine), using a UHPLC-OrbitrapTM system. With this method, we could conduct a detailed analysis of phenolic compounds in red, rosé, and white wines with great selectivity due to sub-ppm mass accuracy. Moreover, accessing the full-scan spectrum enabled us to monitor all the other compounds detected in the sample, facilitating the adaptability of this method to new phenolic compounds if needed.

Quantifying Phospholipids in Organic Samples Using a Hydrophilic Interaction Liquid Chromatography-Inductively Coupled Plasma High-Resolution Mass Spectrometry (HILIC-ICP-HRMS) Method.

In this study, a novel method using hydrophilic interaction liquid chromatography (HILIC) coupled with inductively coupled plasma high-resolution mass spectrometry (ICP-HRMS) was introduced for the quantification of phospholipids in oil samples. The method employed a bridged ethyl hybrid (BEH) stationary phase HILIC column with a tetrahydrofuran (THF)/water mobile phase, enhancing the solubility and detection of phospholipids. During the study, a gradient/matrix effect on ICP-HRMS sensitivity was observed and successfully compensated for experimentally, ensuring reliable quantification results. This approach has proven effective for a wide range of different oil samples including vegetable oils, animal fats, and phospholipid supplements. Notably, this method allowed the direct quantification of phospholipids in oil samples, bypassing the need for prior sample preparation methods, such as solid phase extraction (SPE), thereby streamlining the analytical process. The precision, accuracy, and reduced need for extensive sample preparation offered by this method mark a significant advancement in lipids analysis. Its robustness and broad applicability have substantial implications for industries such as food and renewable energy production, where both efficient and accurate lipid identification and quantification are crucial.

Exploring the mechanisms of Huangqin Qingfei Decoction on acute lung injury by LC-MS combined network pharmacology analysis

BackgroundAcute lung injury (ALI) is a respiratory disease characterized by pulmonary inflammation and increased microvascular permeability, resulting in significant mortality and a lack of effective pharmacological treatment. Huangqin Qingfei Decoction (HQQFD), a Traditional Chinese Medicine (TCM) prescription known for its heat-clearing and detoxifying properties, has shown efficacy in treating ALI. However, the underlying mechanisms of HQQFD to against ALI remain to be elucidated. PurposeThis study aims to discover the mechanisms and the principal bioactive compounds contributing to HQQFD's protective effects in the treatment of ALI. MethodsAn ultra-high performance liquid chromatography-Orbitrap high-resolution mass spectrometry (UHPLC-Orbitrap HRMS) method was employed to characterize the chemical profile in HQQFD and xenobiotics (prototypes and metabolites) in rat lung tissue. Based on prototypes identified, a symptom-guided pharmacological networks of ALI were performed. Molecular docking and extensive literature reviews were conducted to validate our findings. ResultsA total of 105 compounds were identified in HQQFD, and a total of 194 HQQFD-related xenobiotics (30 prototypes and 163 metabolites) were detected in rat lung tissue. Based on prototypes identified in rat lung, a symptom-guided pharmacological networks of ALI were constructed, AKT1, TNF, EGFR, MMP2, GSK3B, STAT3, MAPK8, IL-6, CDK2 and TP53 were finally identified as key targets. Subsequently, 11 compounds with protective and therapeutic activity were selected by molecular docking analysis, including genipin 1-gentiobioside, chrysin-6-C-α-L-arabinoside-8-C-β-d-glucoside, scutellarin, chrysin-6-C-β-d-glucoside-8-C-α-L-arabinoside, 6’’-O-[(E)-p-coumaroyl] genipin-gentiobioside, apigenin 7-O-glucoside, baicalin, dihydrobaicalin, wogonoside, crocin I, crocetin. Bioinformatics and literature analysis suggested that, baicalin, wogonoside, genipin 1-gentiobioside and crocetin may be the primary active compounds of HQQFD, potentially targeting GSK3B, MAPK8, IL-6, AKT1 and TNF for HQQFD in addressing ALI. The therapeutic effects of HQQFD may be mediated through the IL-17 and PI3K-AKT signaling pathways. ConclusionThe predominant components of HQQFD against ALI are baicalein, wogonoside, genipin 1-gentiobiosid and crocetin, with the IL-17 and PI3K-AKT pathways playing crucial roles. This study provides a foundational guide for future research and introduces innovative methods for exploring the mechanisms of other drug combinations or TCM formulas.

LC-HRMS analysis of phospholipids bearing oxylipins

BackgroundSeveral oxylipins including hydroxy- and epoxy-polyunsaturated fatty acids act as lipid mediators. In biological samples they can be present as non-esterified form, but the major part occurs esterified in phospholipids (PL) or other lipids. Esterified oxylipins are quantified indirectly after alkaline hydrolysis as non-esterified oxylipins. However, in this indirect analysis the information in which lipid class oxylipins are bound is lost. In this work, an untargeted liquid chromatography high-resolution mass spectrometry (LC-HRMS) method for the direct analysis of PL bearing oxylipins was developed. ResultsOptimized reversed-phase LC separation achieved a sufficient separation of isobaric and isomeric PL from different lipid classes bearing oxylipin positional isomers. Individual PL species bearing oxylipins were identified based on retention time, precursor ion and characteristic product ions. The bound oxylipin could be characterized based on product ions resulting from the α-cleavage occurring at the hydroxy/epoxy group. PL sn-1/sn-2 isomers were identified based on the neutral loss of the fatty acyl in the sn-2 position. A total of 422 individual oxPL species from 7 different lipid classes i.e., PI, PS, PC, PE, PC-P, PC-O, and PE-P were detected in human serum and cells. This method enabled to determine in which PL class supplemented oxylipins are incorporated in HEK293 cells: 20:4;15OH, 20:4;14Ep, and 20:5;14Ep were mostly bound to PI. 20:4;8Ep and 20:5;8Ep were esterified to PC and PE while other oxylipins were mainly found in PC. SignificanceThe developed LC-HRMS method enables the comprehensive detection as well as the semi-quantification of isobaric and isomeric PL species bearing oxylipins. With this method, we show that the position of the oxidation has a great impact and directs the incorporation of oxylipins into the different PL classes in human cells.

Recent Research Progress on the Chemical Constituents, Pharmacology, and Pharmacokinetics of Alpinae oxyphyllae Fructus.

Alpinae oxyphyllae fructus (AOF), the dried mature fruit of Alpinia oxyphylla Miquel of the Zingiberaceae family, shows many special pharmacological effects. In recent years, there has been an abundance of research results on AOF. In this paper, the new compounds isolated from AOF since 2018 are reviewed, including terpenes, flavonoids, diarylheptanoids, phenolic acid, sterols, alkanes, fats, etc. The isolation methods that were applied include the microwave-assisted method, response surface method, chiral high-performance liquid chromatography-multiple reaction monitoring-mass spectrometry (HPLC-MRM-MS) analytical method, ultra-high-performance liquid chromatography-quadrupole-electrostatic field orbitrap high-resolution mass spectrometry (UPLC-Orbitrap-HRMS) method, ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method, hot water leaching method, ethanol leaching method, and so on. Additionally, the pharmacological effects of AOF found from 2018 to 2024 are also summarized, including neuroprotection, regulation of metabolic disorders, antioxidant activity, antiapoptosis, antiinflammatory activity, antidiabetic activity, antihyperuricemia, antiaging, antidiuresis, immune regulation, anti-tumor activity, renal protection, hepatoprotection, and anti-asthma. This paper provides a reference for further research on AOF.

ICP-MS As a Contributing Tool to Nontarget Screening (NTS) Analysis for Environmental Monitoring.

Due to the increasing number of chemicals released into the environment, nontarget screening (NTS) analysis is a necessary tool for providing comprehensive chemical analysis of environmental pollutants. However, NTS workflows encounter challenges in detecting both known and unknown pollutants with common chromatography high-resolution mass spectrometry (HRMS) methods. Identification of unknowns is hindered by limited elemental composition information, and quantification without identical reference standards is prone to errors. To address these issues, we propose the use of inductively coupled plasma mass spectrometry (ICP-MS) as an element-specific detector. ICP-MS can enhance the confidence of compound identification and improve quantification in NTS due to its element-specific response and unambiguous chemical composition information. Additionally, mass balance calculations for individual elements (F, Br, Cl, etc.) enable assessment of total recovery of those elements and evaluation of NTS workflows. Despite its benefits, implementing ICP-MS in NTS analysis and environmental regulation requires overcoming certain shortcomings and challenges, which are discussed herein.

Bioactivation of cinnamic alcohol in a reconstructed human epidermis model and evaluation of sensitizing potency of the identified metabolites.

Cinnamic alcohol is a natural compound, widely used in fragrances, which can cause allergic contact dermatitis. Cinnamic alcohol lacks intrinsic reactivity and autoxidation or metabolic activation is necessary for it to act as a sensitizer. Bioactivation of cinnamic alcohol was explored using human liver microsomes, human liver S9 and SkinEthic™ Reconstructed Human Epidermis. A targeted multiple reaction monitoring mass spectrometry method was employed to study and quantify cinnamic alcohol along with eight potential phase I or phase II metabolites. The reconstructed human epidermis model, treated with cinnamic alcohol, was also analyzed with a non-targeted high-resolution mass spectrometry method to identify metabolites not included in the targeted method. Two metabolites identified with the targeted method, namely, pOH-cinnamic alcohol and pOH-cinnamic aldehyde, have not previously been identified in a metabolic in vitro system. Their reactivity toward biologically relevant nucleophiles was investigated and compared to their sensitizing potency in vivo in the murine local lymph node assay (LLNA). According to the LLNA, the pOH-cinnamic alcohol is non-sensitizing and pOH-cinnamic aldehyde is a moderate sensitizer. This makes pOH-cinnamic aldehyde less sensitizing than cinnamic aldehyde, which has been found to be a strong sensitizer in the LLNA. This difference in sensitizing potency was supported by the reactivity experiments. Cinnamic sulfate, previously proposed as a potential reactive metabolite of cinnamic alcohol, was not detected in any of the incubations. In addition, experiments examining the reactivity of cinnamic sulfate toward a model peptide revealed no evidence of adduct formation. The only additional metabolite that could be identified with the non-targeted method was a dioxolan derivative. Whether or not this metabolite, or one of its precursors, could contribute to the sensitizing potency of cinnamic alcohol would need further investigation. Cinnamic alcohol is one of the most common fragrance allergens and as it is more effective to patch test with the actual sensitizer than with the prohapten itself, it is important to identify metabolites with sensitizing potency. Further, improved knowledge of metabolic transformations occurring in the skin can improve prediction models for safety assessment of skin products.

A comparative metabolomics analysis of Açaí (Euterpe oleracea Mart.) fruit, food powder, and botanical dietary supplement extracts.

Euterpe oleracea Mart. (açaí) is a botanical of interest to many who seek functional foods that provide antioxidant and anti-inflammatory properties. Cancer patients are increasingly taking botanical dietary supplements containing açaí to complement their conventional therapeutics, which may lead to serious adverse events. Before testing our açaí extracts in vitro for botanical-drug interactions, the goal is to chemically characterize our extracts for compounds whose biological activity in açaí is unknown. The objective of this work was to develop a chemical fingerprinting method for untargeted characterization of açaí samples from a variety of sources, including food products and botanical dietary supplement capsules, made with multiple extraction solvents. An optimized LC-MS method was generated for in-depth untargeted fingerprinting of chemical constituents in açaí extracts. Statistical analysis models were used to describe relationships between the açaí extracts based on molecular features found in both positive and negative mode ESI. In an attempt to elucidate the differences in metabolites among açaí extracts from different cultivars, we identified or tentatively identified 173 metabolites from the 16 extracts made from 6 different sources. Of these compounds, there are 138 reported in açaí for the first time. Statistical models showed similar yet distinct differences between the extracts tested based on the polarity of compounds present and the origin of the source material. A high-resolution mass spectrometry method was generated that allowed us to greatly characterize 16 complex extracts made from different sources of açaí with different extraction solvent polarities.

Doping control analysis of myo-inositol trispyrophosphate and 10 bisphosphonates in equine plasma by ion chromatography-mass spectrometry and its application to clodronic acid horse administration.

Bisphosphonates and myo-inositol trispyrophosphate (ITPP) are two classes of difficult-to-detect polar drugs that are prohibited under the rules of racing. ITPP is a drug capable of increasing the amount of oxygen in hypoxic tissues, and studies have shown that administration of ITPP increases the maximal exercise capacity in mice. The properties of ITPP make it an ideal candidate as a doping agent to enhance performance in racehorses. In recent years, ITPP had indeed been detected in racehorses and confiscated items. As for bisphosphonates, it is especially critical to control their use as since February 2019, the International Agreement on Breeding, Racing and Wagering (IABRW) by the International Federation of Horseracing Authorities (IFHA) had identified specific conditions on which bisphosphonates should not be administered to a racehorse. A recent review of literature shows that there is yet a simultaneous screening method for detecting ITPP and bisphosphonates in equine samples. This paper describes an efficient ion chromatography high-resolution mass spectrometry (IC-HRMS) method for the simultaneous detection of ITPP and 10 bisphosphonates at sub-parts-per-billion (ppb) to low-ppb levels in equine plasma after solid-phase extraction (SPE) and its application to an administration study of clodronic acid in horses.

Feature-Based Molecular Network-Assisted Cannabinoid and Flavonoid Profiling of Cannabis sativa Leaves and Their Antioxidant Properties.

Cannabis sativa (C. sativa) leaves are rich in cannabinoids and flavonoids, which play important antioxidant roles. Since the environmental factors may influence the accumulation of antioxidants in herbal medicines, which affects their activity, this study aimed to investigate the correlation between the chemical composition of C. sativa leaves and their geographical origin and antioxidant activity. Firstly, a high-resolution mass spectrometry method assisted by semi-quantitative feature-based molecular networking (SQFBMN) was established for the characterization and quantitative analysis of C. sativa leaves from various regions. Subsequently, antioxidant activity analysis was conducted on 73 batches of C. sativa leaves, and a partial least squares regression (PLS) model was employed to assess the correlation between the content of cannabinoids and flavonoids in the leaves and their antioxidant activity. A total of 16 cannabinoids and 57 flavonoids were annotated from C. sativa, showing a significant regular geographical distribution. The content of flavonoid-C glycosides in Sichuan leaves is relatively high, and their antioxidant activity is also correspondingly high. However, the leaves in Shaanxi and Xinjiang were primarily composed of flavonoid-O glycosides, and exhibited slightly lower antioxidant activity. A significant positive correlation (p < 0.001) was found between the total flavonoids and cannabinoids and the antioxidant activity of the leaves, and two flavonoids and one cannabinoid were identified as significant contributors.