Quadrupole Time-of-flight Mass Spectrometry Research Articles

Direct Mass Spectrometric Analysis of Brominated Flame Retardants in Synthetic Polymers.

Brominated flame retardants (BFRs) are persistent organic pollutants that pose a major threat to the environment. In this study, a direct insertion probe (DIP) coupled with atmospheric pressure chemical ionization (APCI) quadrupole time-of-flight mass spectrometry (QTOF-MS) was used to characterize additives, especially BFRs, from solid polymer samples with minimal sample preparation. A temperature-programmed DIP analysis, from 150 to 450 °C within 10 min, was utilized to achieve temporal separation of analytes based on their boiling or degradation temperatures, thereby facilitating their easier identification within a single run. Studied BFRs showed different behaviors during the analysis: decabromodiphenyl ether and tetrabromobisphenol A were found to be stable within the studied temperature range, while hexabromocyclododecane already started to debrominate. Our study showed that the DIP-APCI-MS method suited well for the direct qualitative identification of BFRs from polymer matrices. Furthermore, by optimizing the sampling procedure with cryogenic grinding, even quantitative analysis could be performed. The DIP measurements also provided important information about the composition of polymer matrices, including the identification of the comonomers present. Overall, DIP-APCI QTOF-MS was found to be an excellent tool for the compositional analysis of plastic samples. Developing rapid and reliable analysis methods can pave the way for more efficient plastic recycling and the safer use of plastic recyclates.

Development and validation of stability indicating assay method for mitapivat: Identification of novel hydrolytic, photolytic, and oxidative forced degradation products employing quadrupole-time of flight mass spectrometry.

Mitapivat is a novel, first-in-class orally active pyruvate kinase activator approved by the US Food and Drug Administration in 2022 for the treatment of hemolytic anemia. There is no literature available regarding the identification of degradation impurities of mitapivat. The present study deals with the degradation behavior of mitapivat under various stress conditions such as hydrolytic, photolytic, thermal, and oxidative stress. The multivariate analysis found that the independent variables, that is, molarity, temperature, and time, are interacting with each other to affect the degradation of mitapivat. A specific, accurate, and precise high-performance liquid chromatographic (HPLC) method was developed to separate mitapivat from its degradation products. The separation was achieved on the C-18 column (250mm × 4.6mm × 5µm) using the combination of 0.1% formic acid buffer and acetonitrile in gradient elution profile. The method was validated as per the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use Q2(R2) guideline. LC-electrospray ionization-Quadrupole-time of flight was employed to identify degradation products. A total of seven novel degradation products of mitapivat were identified based on tandem mass spectrometry and accurate mass measurement. In-silico toxicity of mitapivat and its degradation products was qualitatively evaluated by the DEREK toxicity prediction tool.

Degradation of Tetracycline through peroxymonosulfate activation with Co/Fe-LDH modified magnetic hydrochar: Synergistic effect and low toxicity

In this work, 2LDH-CoFe2O4@BHC catalyst was prepared by modifying magnetic corncob-based hydrochar (CoFe2O4@BHC) with Co/Fe layered double hydroxide (Co/Fe-LDH), which was used to activate peroxymonosulfate (PMS) for tetracycline (TC) degradation. 2LDH-CoFe2O4@BHC demonstrated effective activation of PMS and rapid removal of TC (100 %) within 10 min by leveraging structural modulation and synergistic interactions among multiple components. In contrast, BHC (26.02 %), CoFe2O4 (59.25 %), and CoFe2O4@BHC (61.88 %) presented poor removal efficiency. Furthermore, it was shown that both the free radicals (SO4•-) and non-free radicals (1O2) were essential in the degradation process, and the catalytic mechanism was revealed to be a synergistic process with the characterization results from in-situ Raman, electrochemical characterization, and X-ray photoelectron spectroscopy (XPS). The catalytic performance of 2LDH-CoFe2O4@BHC was also evaluated using a self-developed fixed-bed reactor, demonstrating its strong stability and resistance to interference during long-term operation. The potential degradation pathway of TC in the 2LDH-CoFe2O4@BHC + PMS system was suggested based on the quadrupole time-of-flight mass spectrometry (QTOF/MS) findings. It was found that the toxicity of the intermediates produced by TC degradation significantly reduced. This study presented an insight for the decomposition of organic pollutants by synthetic biochar-loaded catalysts.

Multi-omics and chemical profiling approaches to understand the material foundation and pharmacological mechanism of sophorae tonkinensis radix et rhizome-induced liver injury in mice

Ethnopharmacological relevanceSophorae tonkinensis Radix et Rhizoma (STR) is an extensively applied traditional Chinese medicine (TCM) in southwest China. However, its clinical application is relatively limited due to its hepatotoxicity effects. Aim of the studyTo understand the material foundation and liver injury mechanism of STR. Materials and methodsChemical compositions in STR and its prototypes in mice were profiled by ultra-performance liquid chromatography coupled quadrupole-time of flight mass spectrometry (UPLC-Q/TOF MS). STR-induced liver injury (SILI) was comprehensively evaluated by STR-treated mice mode. The histopathologic and biochemical analyses were performed to evaluate liver injury levels. Subsequently, network pharmacology and multi-omics were used to analyze the potential mechanism of SILI in vivo. And the target genes were further verified by Western blot. ResultsA total of 152 compounds were identified or tentatively characterized in STR, including 29 alkaloids, 21 organic acids, 75 flavonoids, 1 quinone, and 26 other types. Among them, 19 components were presented in STR-medicated serum. The histopathologic and biochemical analysis revealed that hepatic injury occurred after 4 weeks of intragastric administration of STR. Network pharmacology analysis revealed that IL6, TNF, STAT3, etc. were the main core targets, and the bile secretion might play a key role in SILI. The metabolic pathways such as taurine and hypotaurine metabolism, purine metabolism, and vitamin B6 metabolism were identified in the STR exposed groups. Among them, taurine, hypotaurine, hypoxanthine, pyridoxal, and 4-pyridoxate were selected based on their high impact value and potential biological function in the process of liver injury post STR treatment. ConclusionsThe mechanism and material foundation of SILI were revealed and profiled by a multi-omics strategy combined with network pharmacology and chemical profiling. Meanwhile, new insights were taken into understand the pathological mechanism of SILI.

Development of a LC-QTOF-MS based dilute-and-shoot approach for the botanical discrimination of honeys

Honeys of particular botanical origins can be associated with premium market prices, a trait which also makes them susceptible to fraud. Currently available authenticity testing methods for botanical classification of honeys are either time-consuming or only target a few “known” types of markers. Simple and effective methods are therefore needed to monitor and guarantee the authenticity of honey. In this study, a ‘dilute-and-shoot’ approach using liquid chromatography (LC) coupled to quadrupole time-of-flight-mass spectrometry (QTOF-MS) was applied to the non-targeted fingerprinting of honeys of different floral origin (buckwheat, clover and blueberry). This work investigated for the first time the impact of different instrumental conditions such as the column type, the mobile phase composition, the chromatographic gradient, and the MS fragmentor voltage (in-source collision-induced dissociation) on the botanical classification of honeys as well as the data quality. Results indicated that the data sets obtained for the various LC-QTOF-MS conditions tested were all suitable to discriminate the three honeys of different floral origin regardless of the mathematical model applied (random forest, partial least squares-discriminant analysis, soft independent modelling by class analogy and linear discriminant analysis). The present study investigated different LC-QTOF-MS conditions in a “dilute and shoot” method for honey analysis, in order to establish a relatively fast, simple and reliable analytical method to record the chemical fingerprints of honey. This approach is suitable for marker discovery and will be used for the future development of advanced predictive models for honey botanical origin.

Identification and quantification of microplastics in salts by complementary approaches using pyrolysis-gas chromatography/quadrupole-time of flight mass spectrometry (Py-GC/QTOFMS) and laser direct infrared (LDIR) chemical imaging analysis

Microplastics (MPs) and nanoplastics (NPs) have been suspected as contaminants in various foodstuffs, including salts, all over the world. Regarding the different sizes and polymer types, the mass concentrations of actual plastic particles in salt are not very clear. The purpose of this study is to develop a scalable method for qualitative and quantitative analysis of MPs and NPs by using Pyrolysis Gas Chromatography Quadrupole-Time of Flight mass spectrometry (Py-GC/QTOFMS) to detect their mass concentrations in salt samples. The targeted and suspected lists of polymers in salts were compiled based on the combined results of the high-resolution mass spectrometry (HRMS) full scanning with auxiliary MS dataset and the laser direct infrared (LDIR) chemical imaging analysis. The seven targeted MPs with polymer standards, i.e., polyvinyl chloride (PVC), polymethyl methacrylate (PMMA), polypropylene (PP), polystyrene (PS), polyethylene (PE), polyethylene terephthalate (PET), and polycarbonate (PC), were first subjected to a full MS scanning mode of the Py-GC/QTOFMS analysis. Subsequently, the parental masses of their pyrolysis compounds were used as the seeds to generate the related daughter masses. This process established both retention time and mass-pairs matching for the target MS/MS mode for enabling the identification and quantification of the particles. The suspected MPs with a matching degree >0.65 in the LDIR list were explored either by the full scan MS. Only PVC was identified, and PET was suspected. The Py-GC/QTOFMS result is complementary and comparable to the LDIR detection with the matching degree >0.85. We identified that PVC and PET (suspected) can be measured in both commercial and bulk sea salts, and their concentrations in sea salts are much higher than in rock salts, implying heavy contamination of the seawater.

Analysis of Secondary Metabolites of Elaeagnus Angustifolia Leaves Based on UPLC-Q-TOF-MS.

The leaves of Elaeagnus angustifolia, belonging to the Elaeagnaceae Juss. family, are known for their medicinal properties for relieving cough and asthma, as well as treating dysentery and diarrhea. To establish a rapid qualitative method for the detection of secondary metabolites in leaves of Elaeagnus angustifolia, including the identification and analysis of various secondary metabolites in leaves of Elaeagnus angustifolia. Samples were separated using a Waters ACQUITY H-Class ultra-performance liquid chromatography (UPLC) system (FTN autosampler, quaternary LC pump) and ACQUITY UPLC® BEH C18 column (1.7 μm, 2.1 mm× 100 mm). The flow rate was set to 0.4 mL/min, the injection volume was 1.0 μL, and the column temperature was set to 45 °C. The mobile phase was methanol (A) with) -0.1% formic acid in water (B). Samples were analyzed by quadrupole time-of-flight mass spectrometry (Q-TOF-MS). A total of 182 different secondary metabolites were detected from 10 varieties of leaves of Elaeagnus angustifolia, including 77 flavonoids, 20 steroids, 7 alkaloids, 15 amino acids, 18 organic acids, and 45 other compound types. A method for the rapid analysis of leaves of Elaeagnus angustifolia by UPLC-Q-TOF-MS was established, and the secondary metabolites in leaves of Elaeagnus angustifolia were identified. The enrichment of secondary metabolites in leaves of different varieties of Elaeagnus angustifolia was clarified. The UPLC-Q-TOF-MS method is very fast and possesses a high degree of selectivity, precision, and sensitivity. These findings provide a reliable foundation for the development of medicinal resources derived from Elaeagnus angustifolia leaves.

Metabolomics approach for phenolic compounds profiling of soursop (Annona muricata L.) fruit during postharvest storage.

Soursop (Annona muricata L.) is a crop with medicinal properties and numerous bioactive compounds. Ripening is a complex process that regulates fruit quality and changes in metabolite content, such as flavonoids, polyphenols, and organic acids. This study aimed to analyze the phenolic profiling of soursop fruit ripening. The metabolic changes in different days of storage of soursop fruits were investigated using a semi-metabolomic approach based on ultra-performance liquid chromatography coupled to electrospray ionization quadrupole-time of flight mass spectrometry (UPLC-ESI-QTOF-MS). Further, multivariate analysis such as supervised partial least squares discriminant analysis (PLS-DA) was conducted to identify differential metabolites. A total of 68 metabolites were identified in soursop fruit during postharvest storage. A higher number of metabolites were identified in the Day zero (D0) compared to the Day one (D1), Day three (D3), and Day five (D5), belonging to flavonoids, other polyphenols, phenolic acids, and organic acids. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the pathways of flavone and flavonol biosynthesis, flavonoid biosynthesis, and biosynthesis of secondary metabolites were mostly enriched. Additionally, we included all the compounds and their postharvest storage in the public Phenolics profile database. Here, we show that the stage of ripening has a significant effect on the phenolic content, highlighting the point of cut (D0) and the onset of senescence (D5). The findings of this study provide new insights into the soursop fruit quality and may contribute to the identification of metabolic markers for its storage.

Metabolomic Changes in Plasma of Preterminal Stage of Rhesus Nonhuman Primates Exposed to Lethal Dose of Radiation.

Ionizing radiation exposure is known to induce molecular and cellular injury, inflicting a cascade of potentially catastrophic events leading to tissue and organ damage. Metabolomic analysis allows for the identification and quantification of small molecules downstream of genomic changes induced by radiation exposure. We aimed to characterize metabolomic changes that underscore the prefinal stage of lethally irradiated rhesus nonhuman primates (NHPs). Peripheral blood was drawn at baseline, post-exposure, as well as at the preterminal stage in NHPs (immediately prior to death in moribund NHPs) that did not survive exposure with 7.2 Gy total-body radiation (LD70/60). Herein, we analyzed global metabolomic changes using ultra-performance liquid chromatography (UPLC) quadrupole time-of-flight mass spectrometry (QTOF-MS) in plasma samples of NHPs collected at various timepoints in relation to irradiation. The overall goal was to identify metabolic shifts present immediately prior to death. Our findings showed radiation induced significant time-dependent metabolic perturbations when compared to pre-irradiation profiles, particularly in glycerophospholipid metabolism and steroid hormone biosynthesis and metabolism pathways. These findings provide valuable insights for identifying biomarkers for lethality, which may be helpful for triage during a mass casualty scenario.

In Search of Authenticity Biomarkers in Food Supplements Containing Sea Buckthorn: A Metabolomics Approach.

Sea buckthorn (Hippophae rhamnoides L.) (SB) is increasingly consumed worldwide as a food and food supplement. The remarkable richness in biologically active phytochemicals (polyphenols, carotenoids, sterols, vitamins) is responsible for its purported nutritional and health-promoting effects. Despite the considerable interest and high market demand for SB-based supplements, a limited number of studies report on the authentication of such commercially available products. Herein, untargeted metabolomics based on ultra-high-performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry (UHPLC-QTOF-ESI+MS) were able to compare the phytochemical fingerprint of leaves, berries, and various categories of SB-berry herbal supplements (teas, capsules, tablets, liquids). By untargeted metabolomics, a multivariate discrimination analysis and a univariate approach (t-test and ANOVA) showed some putative authentication biomarkers for berries, e.g., xylitol, violaxanthin, tryptophan, quinic acid, quercetin-3-rutinoside. Significant dominant molecules were found for leaves: luteolin-5-glucoside, arginine, isorhamnetin 3-rutinoside, serotonin, and tocopherol. The univariate analysis showed discriminations between the different classes of food supplements using similar algorithms. Finally, eight molecules were selected and considered significant putative authentication biomarkers. Further studies will be focused on quantitative evaluation.

Molecular formula assignment of dissolved organic matter by ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry using two non-targeted data processing approaches: A case study from recirculating aquaculture systems

BackgroundThe accumulation of dissolved organic matter (DOM) poses an issue in the management of the water quality from recirculating aquaculture systems (RAS), but its characterization is often not detailed enough to understand the DOM transformations in RAS. In this study, we investigated the application of two distinct non-targeted data processing approaches using ultra-performance liquid chromatography (UPLC) with quadrupole time-of-flight mass spectrometry (QTOF-MS) and two software with different algorithmic designs: PetroOrg and Progenesis QI to accurately characterize the molecular composition of DOM in RAS by UPLC-QTOF-MS. ResultsThe UPLC-QTOF-MS resolution in combination with PetroOrg and Progenesis QI software successfully assigned 912 and 106 unique elemental compositions, respectively, including compounds containing carbon, hydrogen, and oxygen (CHO) and nitrogen-containing CHO compounds (CHON), in the DOM samples from RAS. The results of these two distinct data processing approaches were consistent with the list of DOM formulas from RAS identified by higher resolution mass spectrometry techniques confirming their reliability. PetroOrg approach revealed only compositional information in the DOM samples from RAS, while Progenesis QI in addition to identifying new elemental compositions, increased their chemical space by giving information about their polarity and their possible key structures. DOM samples from RAS were found to be rich in unsaturated CHO compounds, with tentatively key structures of terpenoids with medium polarity indicating natural origins in their composition. The analysis also revealed probable structures of sucrose fatty acid esters and polyethylene glycol, indicating anthropogenic sources. Significance and NoveltyThe combination of these two non-targeted data processing approaches significantly improves the characterization of the complex mixture of DOM from RAS by UPLC-QTOF-MS reporting for the first time accurate DOM results in terms of its composition, while proposing its key structures. The presented methods can also be used to analyze different DOM samples with other HRMS techniques and software.

Comprehensive characterization and detection of nut allergens in bakery foods using Q-TOF mass spectrometry and bioinformatics

Abstract Food allergy is a growing health issue worldwide and the demand for sensitive, robust and high-throughput analytical methods is rising. In recent years, mass spectrometry-based methods have been established for multiple food allergen detection. In the present study, a novel method was developed for the simultaneous detection of almond, cashew, peanut, and walnut allergens in bakery foods using liquid chromatography–mass spectrometry. Proteins unique to these four ingredients were extracted, followed by trypsin digestion, quadrupole time-of-flight (Q-TOF) mass spectrometry and bioinformatics analysis. The raw data were processed by de-novo sequencing module plus PEAKS DB (database search) module of the PEAKS software to screen peptides specific to each nut species. The thermal stability and uniqueness of these candidate peptides were further verified using triple quadrupole mass spectrometry (QQQ-MS) in multiple reaction monitoring (MRM) mode. Each nut species was represented by four peptides, all of which were validated for label-free quantification (LFQ). Calibration curves were constructed with good linearity and correlation coefficient (r2) greater than 0.99. The limits of detection (LODs) were determined to range from 0.11 to 0.31 mg/kg, and were compared with the reference doses proposed by Voluntary Incidental Trace Allergen Labelling (VITAL). The recoveries of the developed method in incurred bakery food matrices ranged from 72.5% to 92.1% with relative standard deviations (RSD) of <5.2%. The detection of undeclared allergens in commercial bakery food samples confirmed the presence of these allergens. In conclusion, this method provides insight into the qualitative and quantitative detection of trace levels of nut allergens in bakery foods.

EVOO supplement prevents type 1 diabetes by modulating gut microbiota and serum metabolites in NOD mice

AimsExtra virgin olive oil (EVOO) is the highest quality olive oil available and has been shown to regulate postprandial blood glucose in patients with type 1 diabetes (T1D). However, it remains uncertain whether EVOO can prevent the onset of T1D. In this study, we investigated the potential preventive effect of orally administered EVOO on T1D in non-obese diabetic (NOD) mice. Main methodsWe analyzed changes in fecal microbes using 16 s rDNA sequencing and serum metabolites using Ultra High-Performance Liquid Chromatography and Quadrupole Time-of-Flight Mass Spectrometry (Q-TOF-MS). Key findingsOur findings showed that EVOO supplementation in NOD mice slowed gastric emptying, reduced insulitis, and delayed T1D onset. Moreover, EVOO altered the composition of fecal microbes, increasing the Bacteroidetes/Firmicutes ratio, and promoting the growth of short-chain fatty acids (SCFAs)-producing bacteria, such as Lachnoclostridium and Ruminococcaceae_UCG-005. Moreover, it also increased beneficial serum metabolites, including unsaturated fatty acid and triterpenoid, which positively correlated with the increased SCFA-producing bacteria and negatively correlated with the disease indicators. Conversely, most decreased serum lipid metabolites, such as Oleamide, showed the opposite trend. SignificanceOur study demonstrates that EVOO may ameliorate pancreas inflammation and prevent T1D onset in NOD mice by modulating gut microbiota and serum metabolites.

Modulating the >Co(II)/Co(III) redox cycling via confinement of cobalt with WS2 for the ultrafast sulfite activation

Sulfite autoxidation in combination with the cobalt-based heterogeneous activators, has recently emerged as the efficient sulfate radical (SO4•−) generation process for organic micropollutant abatement in the water and wastewater treatment, yet the sluggish >Co(II)/Co(III) redox cycling currently compromises the efficacy of radical generation and the potential applications. Herein, regarding that the reductive W(IV) species in WS2 can modulate the >Co(II)/Co(III) redox cycling in the advanced oxidation processes, confinement of cobalt with WS2 (Co-WS2) is designed and characterized. The Co-WS2/sulfite process achieves an ultrafast tetracycline (TC) abatement (∼100 % abatement of TC within 1 min) under circumneutral conditions with lower dosage of sulfite and activator, outperforming the current cobalt-based heterogeneous counterparts. The dominant reactive radicals are identified as SO4•− and hydroxyl radical (HO•), which are quantified to be 9.7 μM and 4.5 μM, respectively. The superior radical generation efficiency and the concomitant TC abatement rely on the excellent redox properties and electron transfer capability of Co-WS2. The inter-transformation of >Co(II)/>Co(III) can be accelerated via the involvement of the reductive W(IV) species with the redox-reversibility of the W(IV)/W(VI) couple in the presence of sulfite. The TC degradation intermediates and the corresponding pathways are also proposed according to the ultra-performance liquid chromatography and quadrupole-time of flight mass spectrometry (UPLC-QTOF-MS) analysis. In addition, the influences of the reactant dosage, coexisting anions (HCO3−, HPO42−, Cl− and NO3−), humic acid and the various real water matrices on TC abatement are thoroughly explored. Especially, the Co-WS2/sulfite process is advantageous owing to the negligible effect of the coexisting anions on the TC abatement. This study provides a novel heterogeneous activator for significantly improving sulfite activation efficacy to achieve the efficient organic micropollutant abatement.

Quality evaluation of Angelica Sinensis Radix dispensing granules by integrating microvascular activity and chemical analysis

Ethnopharmacological relevanceAs a new form of crude slices of traditional Chinese medicine (TCM), traditional Chinese medicine dispensing granules (TCMDGs) have been used for clinical formula. It is necessary to evaluate whether the chemical composition and biological activity are consistent among the different batches. Angelica Sinensis Radix (ASR), the root of Angelica sinensis (Oliv.) Diels, is one of the most frequently used medicinal materials in gynecology, senile and cardiovascular diseases. In this paper, the quality of TCMDGs is examined taking the Angelica Sinensis Radix dispensing granules (ASRDGs) as a typical case. Aim of the studyIn this study, integrating bioequivalence and chemical analysis was used to evaluate the quality of dispensing granules taking ASRDGs as a typical case. Materials and methodsAccording to the clinical efficacy of ASR, the intestinal absorption liquid of ASRDGs (IAL-ASRDGs) in 15 batches prepared by the everted gut sac (EGS) method was used to evaluate its effects of vasodilatation on isolated vascular rings. Then, the chemical profiling analysis of IAL-ASRDGs from the 15 batches was carried out by ultra-high performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry (UPLC-Q-TOF-MS). The components in IAL-ASRDGs were identified using mass spectrometry data and the obtained reference standards. Pearson correlation analysis was further performed for the selection of quality control markers based on the extracted ion chromatograms of the identified compounds and vasodilatory activities of different batches of IAL-ASRDGs. Moreover, the selected chemical components in ASRDGs were further verified by vasodilatory activities and quantitatively analyzed by ultra-high performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-QQQ-MS). ResultsThe IAL-ASRDGs showed favorable vasodilatory activities. There were significant differences among the 15 batches. The ranges of maximum vasodilation rate (%) and EC50 were 69.33 ± 7.16 to 19.52 ± 5.05 and 0.07–25.58 g raw materials/mL, respectively. A total of 46 compounds in IAL-ASRDGs were identified based on accurate mass measurements, fragmentation behavior and the reference standards. Among them, 8 compounds including butylidenephthalide, butylphthalide and senkyunolide A showed positive correlation with vasodilatory effect of IAL-ASRDGs. The 8 compounds were further verified, showing obvious vasodilatory activities. The content of the 8 compounds also showed some differences in 15 batches of ASRDGs. Among them, the content of ferulic acid, senkyunolide I and senkyunolide H varied the most in different batches of ASRDGs. By Pearson correlation analysis, the total content of senkyunolides (senkyunolide A, senkyunolide I and senkyunolide H) in ASRDGs was found to reflect the vasodilatory activity of ASRDGs mostly. ConclusionThis study provides new strategies for the quality assessment by bioequivalence and explore the chemical quality control markers for ASRDGs.

Qualitative and quantitative evaluations of Chuanxiong dispensing granules by using chemical fingerprint in combination with chemometrics methods

To better elucidate the chemical constituents and evaluate the quality consistency of Chuanxiong dispensing granules (CDG), qualitative and quantitative analyses were performed in this study. Firstly, a high-performance liquid chromatography-diode array detector (HPLC-DAD) based fingerprint was constructed by 12 batches of CDGs from different manufacturers, in which 16 common peaks were assigned. Then, two of them were directionally isolated for structural elucidation. According to the nuclear magnetic resonance (NMR) and mass spectrometry (MS) spectra, 5,6-dihydrophthalic acid was identified as novel compound, and 8-O-4/8-O-4-dehydrotriferulic acid was firstly discovered in plant belonging to the genus Ligusticum. Secondly, a total of 46 components were detected in CDG using high performance liquid chromatography coupled with quadrupole-time of flight mass spectrometry (HPLC-Q-TOF-MS), and 14 of them were unambiguously identified by comparing with reference standards. Additionally, a HPLC-DAD method was firstly established to quantify 10 characteristic peaks specified in the China National Standard of CDG, and the results revealed that ferulic acid (1.71 mg/g), chlorogenic acid (1.14 mg/g), 5,6-dihydrophthalic acid (1.13 mg/g), and senkyunolide I (1.13 mg/g) are the major components in CDGs. Chemometrics analyses suggested that phenolic acids are more important than phthalides in discrimination of CDGs from different manufacturers.

Volatile linalool activates grapevine resistance against downy mildew with changes in the leaf metabolome

Volatile organic compounds (VOCs) are produced by plants in response to biotic and abiotic stimuli. In grapevine, volatile terpenoids are triggered by downy mildew infection (caused by Plasmopara viticola), suggesting their involvement in plant defense responses. In particular, linalool was detected in leaves of downy mildew-resistant genotypes, but no information is available on its involvement in the defense mechanisms against P. viticola. The aim of this study was to investigate the defense mechanisms activated by linalool in grapevine leaves against P. viticola and to identify metabolic changes associated with linalool-induced resistance. Linalool treatment reduced downy mildew severity on leaf disks of susceptible grapevines (cultivar Pinot noir) and stimulated callose deposition at the sites of P. viticola infection. Moreover, the upregulation of defense-related genes was found in linalool-treated leaf disks, indicating the activation of grapevine defense mechanisms of salicylic acid and jasmonic acid pathways. Linalool treatment caused changes in the leaf metabolome of mock-inoculated and P. viticola-inoculated samples at one and six days post inoculation, as revealed by ultra-high pressure liquid chromatography-electrospray ionization-high-resolution quadrupole time of flight-mass spectrometry. Pathway analysis of annotated features with significant increases and decreases in abundance revealed the reprogramming of amino acid, phenylpropanoid, and terpenoid metabolisms in response to linalool treatment and P. viticola inoculation. In particular, features with significant increases in abundance in linalool-treated samples mainly belonged to putative phenylpropanoids, putative terpenoids, putative lipids, and lipid-like compounds, including molecules possibly associated with plant defense against pathogens, such as 2-phenylethanol, 2,4-heptadienal, α-terpineol, citral, and geraniol. These results demonstrated that linalool induces grapevine resistance against downy mildew, acting as a signaling molecule for plant resistance induction.

Huangqi Jianzhong Tang treats chronic atrophic gastritis rats by regulating intestinal flora and conjugated bile acid metabolism.

Huangqi Jianzhong Tang (HQJZ) is effective for treating chronic atrophic gastritis (CAG). The present study was carried out to reveal the mechanism of HQJZ in CAG rats. The metabolism and microbial composition of the cecal contents in CAG rats were analyzed through the integration of an untargeted metabolomic approach using ultra-high-performance liquid chromatography coupled with the quadrupole-time of flight mass spectrometry (UHPLC-QTOF-MS) and 16S rRNA gene sequencing, respectively. Finally, MetOrigin analyses were performed to explore the relationship between differential metabolites and intestinal flora. The results showed that HQJZ could significantly regulate metabolic disorders, especially conjugated acid metabolites. 16S rRNA gene sequencing analysis illustrated that HQJZ decreased the abundance of Acetobacter, Desulfovibrio, Escherichia, and Shigella. MetOrigin metabolite traceability analysis showed that the six bile acids associated with HQJZ efficacy included three bacteria-host cometabolites, which were involved in the primary bile acid biosynthesis pathway. Research presented here confirmed that conjugated bile acid metabolism was key to the treatment of CAG by HQJZ and correlates strongly with Bacteroides acidifaciens and Prevotella copri. These findings provide new insights into the mechanisms to explain the efficacy of HQJZ.

Rapid Analysis of 18 Flavonoids in Tea by Ultrahigh-Performance Liquid Chromatography Coupled with Quadrupole-Time of Flight Mass Spectrometry

A method was established for the determination of 18 flavonoids in tea by ultra-performance liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry (UPLC-Q-TOF/MS). The tea samples were extracted by 70% (V/V) methanol aqueous solution, and separation was achieved on a Kinetex F5 column (2.1 mm × 100 mm, 2.6 μm) with methanol and 0.1% formic acid in water as the mobile phase with a gradient elution. The samples were detected in TOF/MS and information-dependent acquisition (IDA)-MS/MS modes. The results showed that the relative standard deviations of 18 flavonoids were less than 5.0 ppm. The correlation coefficients (R2) of the linear equation were greater than 0.998 in the range of 0.10–200 ng/mL. The limits of detection were 0.0010–0.040 ppm, and the limits of quantification were 0.0020–0.10 ppm. The recoveries ranged from 73.8% to 107% at spiked levels of 0.0020–1.0 ppm, with relative standard deviations (RSDs) being less than 10%. The method was simple, specific, and reliable. It could be used for the rapid screening and quantitative analysis of flavonoids in tea.

Comparisons of phenolic compounds and antioxidant activities during different growth stages in Artemisia gmelinii Weber ex Stechm with UPLC-QTOF/MS based on a metabolomics approach

Metabolomics approaches are becoming popular for a rational and efficient approach to standardize research including optimal harvest time determination to improve the values of plant raw materials. In this study, multivariate statistical analysis of metabolites from Artemisia gmelinii Weber ex Stechm (AG) by growth stage according to harvest time (from June to October) was performed by ultra-performance liquid chromatography (UPLC) coupled with quadrupole time of flight mass spectrometry (Q-TOF/MS). Secondary metabolite analysis through PCA provided clearly distinguishable patterns and qualitative R2X values (93.7%) for the corresponding markers. From the OPLS-DA, ten phenolic compounds were found as biomarkers exhibiting distinct patterns according to the harvesting periods (June-Aug: five phenolic acids, Aug-Oct: five flavonoids), and the contents of these phenolic compounds, well-known antioxidants, were increased according to the growth period (Oct > Aug > June). In conclusion, the harvesting time of plant raw materials could be sufficiently determined through the metabolomics study of secondary metabolites.