Total Ion Chromatogram Research Articles

Chemometric-based analysis and bioassay guided identification of potent compounds with intestinal motility promoting effects from Dalitong Granules

Ethnopharmacological relevanceDalitong Granules (DLT), a potent Traditional Chinese Medicine known for its ability to promote gastrointestinal motility, is widely used in clinical practice for the treatment of Functional Dyspepsia (FD). Despite the remarkable clinical efficacy of DLT, the specific components responsible for its effectiveness remains unclear. Aim of the studyThe study aimed to identify potential active ingredients of DLT for treating FD through spectrum-effect relationship analysis, multivariate statistical analysis and network pharmacology analysis. The efficacy of these identified compounds was subsequently validated using the zebrafish intestinal peristalsis model. Materials and methodsThe fingerprints of various solvent-extracted DLT were analyzed using high performance liquid chromatography coupled with tandem high-resolution mass spectrometry. The intestinal motility-promoting activities of DLT extracted by different solvents were evaluated through an intestinal propulsion test in mice. Potential therapeutic substances in DLT for treating FD were screened via chemometric analysis based on spectrum-effect relationship analysis. The correlation between the intensity of common peaks in the total ion chromatogram and the pharmacodynamic indices was assessed using multivariate statistical analysis. Additionally, given the complexity of Traditional Chinese Medicine, which comprises multiple components and targets, a network pharmacology analysis was performed to investigate the potential active ingredients in DLT. Finally, the pharmacological effects of these compounds in DLT were validated using a zebrafish intestinal motility model. ResultsThrough spectral-effect relationships analysis and network pharmacology analysis, it was determined that ten ingredients in DLT contribute to the promotion of intestinal motility. In a zebrafish intestinal motility model, it was observed that eight chemicals (excluding tetrahydropalmatine) demonstrate favorable activity of promoting gastrointestinal motility. These findings suggest that these ingredients may serve as potential therapeutic agents for improving gastric motility disorders. ConclusionsThis study employed spectral-effect relationship and network pharmacology analysis to identify the active ingredients in DLT. The findings were then validated using a zebrafish intestinal peristalsis model. These results provide a scientific foundation for the clinical application of DLT as a key traditional herbal formula for managing FD.

Qing Hua Chang Yin ameliorates chronic colitis in mice by inhibiting PERK–ATF4–CHOP pathway of ER stress and the NF-κB signalling pathway

Context Ulcerative colitis has been clinically treated with Qing Hua Chang Yin (QHCY), a traditional Chinese medicine formula. However, its precise mechanisms in mitigating chronic colitis are largely uncharted. Objective To elucidate the therapeutic efficiency of QHCY on chronic colitis and explore its underlying molecular mechanisms. Materials and methods A total ion chromatogram fingerprint of QHCY was analysed. Chronic colitis was induced in male C57BL/6 mice using 2% dextran sodium sulphate (DSS) over 49 days. Mice were divided into control, DSS, DSS + QHCY (0.8, 1.6 and 3.2 g/kg/d dose, respectively) and DSS + mesalazine (0.2 g/kg/d) groups (n = 6). Mice were intragastrically administered QHCY or mesalazine for 49 days. The changes of disease activity index (DAI), colon length, colon histomorphology and serum pro-inflammatory factors in mice were observed. RNA sequencing was utilized to identify the differentially expressed transcripts (DETs) in colonic tissues and the associated signalling pathways. The expression of endoplasmic reticulum (ER) stress-related protein and NF-κB signalling pathway-related proteins in colonic tissues was detected by immunohistochemistry staining. Results Forty-seven compounds were identified in QHCY. Compared with the DSS group, QHCY significantly improved symptoms of chronic colitis like DAI increase, weight loss, colon shortening and histological damage. It notably reduced serum levels of IL-6, IL-1β and TNF-α. QHCY suppressed the activation of PERK–ATF4–CHOP pathway of ER stress and NF-κB signalling pathways in colonic tissues. Discussion and conclusions The findings in this study provide novel insights into the potential of QHCY in treating chronic colitis patients.

AntDAS-GCMS: A New Comprehensive Data Analysis Platform for GC-MS-Based Untargeted Metabolomics with the Advantage of Addressing the Time Shift Problem.

Over the years, a number of state-of-the-art data analysis tools have been developed to provide a comprehensive analysis of data collected from gas chromatography-mass spectrometry (GC-MS). Unfortunately, the time shift problem remains unsolved in these tools. Here, we developed a novel comprehensive data analysis strategy for GC-MS-based untargeted metabolomics (AntDAS-GCMS) to perform total ion chromatogram peak detection, peak resolution, time shift correction, component registration, statistical analysis, and compound identification. Time shift correction was specifically optimized in this work. The information on mass spectra and elution profiles of compounds was used to search for inherent landmarks within analyzed samples to resolve the time shift problem across samples efficiently and accurately. The performance of our AntDAS-GCMS was comprehensively investigated by using four complex GC-MS data sets with various types of time shift problems. Meanwhile, AntDAS-GCMS was compared with advanced GC-MS data analysis tools and classic time shift correction methods. Results indicated that AntDAS-GCMS could achieve the best performance compared to the other methods.

Assessment of artificial intelligence to detect gasoline in fire debris using HS-SPME-GC/MS and transfer learning.

Due to the complex nature of the chemical compositions of ignitable liquids (IL) and the interferences from fire debris matrices, interpreting chromatographic data poses challenges to analysts. In this work, artificial intelligence (AI) was developed by transfer learning in a convolutional neural network (CNN), GoogLeNet. The image classification AI was fine-tuned to create intelligent classification systems to discriminate samples containing gasoline residues from burned substrates. All ground truth samples were analyzed by headspace solid-phase microextraction (HS-SPME) coupled with a gas chromatograph and mass spectrometer (GC/MS). The HS-SPME-GC/MS data were transformed into three types of image presentations, that is, heatmaps, extracted ion heatmaps, and total ion chromatograms. The abundance and mass-to-charge ratios of each scan were converted into image patterns that are characteristic of the chemical profiles of gasoline. The transfer learning data were labeled as "gasoline present" and "gasoline absent" classes. The assessment results demonstrated that all AI models achieved 100 ± 0% accuracy in identifying neat gasoline. When the models were assessed using the spiked samples, the AI model developed using the extracted ion heatmap obtained the highest accuracy rate (95.9 ± 0.4%), which was greater than those obtained by other machine learning models, ranging from 17.3 ± 0.7% to 78.7 ± 0.7%. The proposed work demonstrated that the heatmaps created from GC/MS data can represent chemical features from the samples. Additionally, the pretrained CNN models are readily available in the transfer learning workflow to develop AI for GC/MS data interpretation in fire debris analysis.

Spectral and mass characterization of kinetic conversion from retinoids to retinoic acid in an in vitro 3-D human skin equivalent model

To investigate the effect of retinoids, such as retinol (ROL), retinal (RAL), and retinyl palmitate (RP), on epidermal integrity, skin deposition, and bioconversion to retinoic acid (RA). 3-D human skin equivalent model (EpiDermFT™) was used. Epidermal cellular integrity measured by TEER values was significantly higher for a topical treatment of ROL and RAL than RP (p < 0.05). The skin deposition (μM) of ROL and RAL was approximately 269.54 ± 73.94 and 211.35 ± 20.96, respectively, greater than that of RP (63.70 ± 37.97) over 2 h incubation. Spectral changes were revealed that the CO maximum absorbance occurred between 1600∼1800 cm−1 and was greater from ROL than that from RAL and RP, indicating conjugation of R–OH to R-CHO or R-COOH could strongly occur after ROL treatment. Subsequently, a metabolite from the bioconversion of ROL and RAL was identified as RA, which has a product ion of m/z 283.06, by using liquid a chromatography-mass spectrometry (LC-MS) - total ion chromatogram (TIC). The amount of bioconversion from ROL and RAL to RA in artificial skin was 0.68 ± 0.13 and 0.70 ± 0.10 μM at 2 h and 0.60 ± 0.04 and 0.57 ± 0.06 μM at 24 h, respectively. RA was not detected in the skin and the receiver compartment after RP treatment. ROL could be a useful dermatological ingredient to maintain epidermal integrity more effectively, more stably deposit on the skin, and more steadily metabolize to RA than other retinoids such as RAL and RP.

Comprehensive identifying flavonoids in Citri Reticulatae Pericarpium using a novel strategy based on precursor ions locked and targeted MS/MS analysis

Citri Reticulatae Pericarpium is a traditional Chinese medicine with extremely high health benefits as well as clinical value. In vivo and in vitro tests have proved that its main active secondary metabolites are flavonoids. However, they have not been comprehensively analyzed up to now mainly due to lack of suitable analysis method. To solve this problem, a novel strategy based on precursor ions locked and targeted MS/MS analysis was proposed. Firstly, the database of the flavonoids previously isolated from Citri Reticulatae Pericarpium was established to obtain the characteristics of their precursor ions. Secondly, after performing the full MS scan of the extract, all compounds in the total ion chromatogram were extracted by Compound Discoverer software. Thirdly, the precursor ions of the flavonoids were locked from the extracted compounds according to their characteristics, forming a precursor ions list. Finally, the precursor ions in the constructed list were performed targeted MS/MS analysis for structures characterization. As a result, total 187 flavonoids were successfully identified, and except for flavones, flavonols as well as dihydroflavones, some chalcones were also characterized from Citri Reticulatae Pericarpium for the first time.

Utilizing Cost-Effective Determination Techniques to Authenticate Cosmetics

(1) Background: The adulteration of cosmetics has become increasingly common, which seriously harms ordinary consumers. The counterfeit cosmetics pointed out in this study mainly refer to imitating genuine products in terms of ingredients and packaging. Ordinary consumers cannot distinguish their authenticity solely based on appearance and daily use. If there is a convenient and low-cost detection method that can expose this phenomenon of adulteration, it will be able to expose adulteration and protect the interests of consumers quickly and conveniently. (2) Methods: MALDI-TOF, GC-MS, and mid-IR were used to develop low-cost and fast methods for identifying the authenticity of cosmetics. Five types of liquid and five types of emulsion cosmetics purchased from container and wholesale markets were analyzed using the three instruments mentioned above, and their spectra and acquired data were carefully compared to determine their authenticity. MALDI-TOF and GC-MS directly tested cosmetic samples, and mid-IR spectroscopy tested the ink on the outer packaging of cosmetics. (3) Results: The data procured by MALDI-TOF can provide a representation of its product attributes; two liquid samples and one paste sample demonstrated inconsistent test outcomes with the corresponding reference samples, suggesting contamination. The results of GC-MS can illustrate the substance count within cosmetic samples; the comparison outcomes of the total ion chromatogram indicate that one paste sample was a counterfeit. The results attained from mid-IR were consonant with those acquired from the MALDI-TOF analysis and GC-MS. (4) Conclusions: These three newly developed techniques can all be effectively utilized for the task of detecting cosmetic adulteration and quality control in the manufacturing process. With regard to user-friendliness and rapidity, both MALDI-TOF and mid-IR outperform GC-MS, demonstrating consistently superior levels of detection. Conversely, GC-MS has unique advantages in identifying emulsion cosmetics containing a high amount of weak polarity and volatile substances. Consequently, these corresponding methods could serve as efficient and cost-effective ways to detect authenticity issues in real-world cosmetic products.

Comparison of Approaches for Authentication of Commercial Terpinen-4-ol-type Tea Tree Oils Using Chiral GC/MS.

A global demand for tea tree oil (TTO) has resulted in increased adulteration in commercial products. In this study, we use a novel enantiomeric gas chromatography mass spectrometry method for chiral analysis of key terpenes ((±)-terpinen-4-ol, (±)-α-terpineol, and (±)-limonene) and quantification of components present at >0.01% to test different methods of identifying adulterated TTO. Data from authentic Australian (n = 88) and oxidized (n = 12) TTO samples of known provenance were consistent with recommended ranges in ISO 4730:2017 and previously published enantiomeric ratios, with p-cymene identified as the major marker of TTO oxidation. The 15 ISO 4730:2017 constituents comprised between 84.5 and 89.8% of the total ion chromatogram (TIC) peak area. An additional 53 peaks were detected in all samples (7.3-11.0% of TIC peak area), while an additional 43 peaks were detected in between 0 and 99% (0.15-2.0% of the TIC peak area). Analysis of nine commercial samples demonstrated that comparison to the ISO 4730:2017 standard does not always identify adulterated TTO samples. While statistical analysis of minor components in TTO did identify two commercial samples that differed from authentic TTO, the (+)-enantiomer percentages for limonene, terpinen-4-ol, and α-terpineol provided clearer evidence that these samples were adulterated. Thus, straightforward identification of unadulterated and unoxidized TTO could be based on analysis of appropriate enantiomeric ratios and quantitation of the p-cymene percentage.

Method validation and characterization of stress degradation products of azelastine hydrochloride using LC-UV/PDA and LC-Q/TOF-MS studies.

Azelastine HCl is a second-generation H1 -receptor antagonist approved by the US Food and Drug Administration (US FDA) for treating seasonal allergic rhinitis and non-allergic vasomotor rhinitis. This study encompasses the validation of a liquid chromatography-ultra violet photo diode array (LC-UV/PDA) method for the drug and its extension to liquid chromatography/quadrupole time-of-flightmassspectrometry (LC-Q/TOF-MS) studies for identification and characterization of various stress degradation products of the drug. Stress degradation of azelastine HCl was undertaken under the International Council for Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) prescribed conditions of hydrolytic, photolytic, oxidative, and thermal stress. The degraded drug solutions were analyzed using Ultra Performance Liquid Chromatography (UPLC) employing a C18 (100 × 4.6mm; 2.6μ, Kinetex) column by isocratic elution. Detection wavelength was 241 nm. The degradation products were identified and characterized using UPLC-MS/TOF studies, and an attempt was made to isolate one of the degradation products by solvent extraction. The drug was found to significantly degrade under acidic/alkaline/neutral photolytic, oxidative, and alkaline hydrolytic conditions. Six degradation products (I-VI) were identified through LC-Q/TOF-MS studies that were adequately resolved from the drug with the developed UPLC method. All degradation products (I-VI) were ionized in the total ion chromatogram (TIC) in the LC-MS studies, and these were identified and characterized, and the degradation pathway of the drug was postulated. One of the oxidation products isolated from the degraded drug solution was characterized through differential scanning calorimetry, Fourier-transform infrared spectroscopy, and nuclear magnetic resonance spectral data. Six degradation products generated from stress degradation studies on azelastine HCl were adequately resolved through LC-UV/PDA studies followed by method validation. These were successfully identified and characterized through LC-Q/TOF-MS studies, and the degradation pathways for the generation of these products from the drug have been postulated.

A pyrolysis‐gas chromatography/mass spectrometry study of volatile compounds produced by wood‐based materials

AbstractThe pyrolysis by‐products of five common wood‐based construction materials (low‐density wood fiberboard, oriented strand board, pine, particle board, and plywood) were studied using pyrolysis‐gas chromatography/mass spectrometry. Samples of wood‐based materials were pyrolyzed under helium from 300 to 800°C to further understand the production of compounds that may become airborne and available for respiratory and dermal exposure. Benzene, toluene, ethylbenzene, p‐xylene, styrene, and naphthalene were specifically targeted since these compounds are common by‐products of pyrolysis. These compounds have been measured in previous live fire scenarios and are associated with human health concerns. The generated pyrolysates were separated and identified with a gas chromatography/mass spectrometry instrument. The results from total ion chromatograms and selected ion monitoring chromatograms were analyzed to compare the abundance of chemicals of interest generated during pyrolysis. Oriented strand board and plywood generated the greatest total concentration of the targeted volatile organic compounds. Plywood and particle boards generated the largest variety in results. Samples from solid pine boards generated the smallest number of volatile compounds, followed by low‐density wood fiberboard that is manufactured with wood fibers, starch, and wax. Notably, pyrolysis by‐products are not the sole compounds generated during the combustion of biomass and these products evolve when they are exposed to the conditions of combustion. Our future work plans to study the combustion by‐products of these materials.

Influence of extraction windows for data-independent acquisition on feature annotation during suspect screening

Non-target analysis (NTA) using high-resolution mass spectrometry is becoming a useful approach to screen for suspect and unknown chemicals. For comprehensive analyses, data-independent acquisition (DIA), like Sequential Windowed Acquisition of all THeoretical Mass Spectra (SWATH-MS) on Sciex instruments, is necessary, usually followed by library matching for feature annotation. The choice of parameters, such as acquisition window number and size, may influence the comprehensiveness of the suspect features detected. The goal of this study was to assess how mass spectrometric DIA settings may influence the ability to obtain confident annotations and identifications of features in environmental (river water, passive sample extract (PSE)), wastewater (unpreserved and acidified) and biological (urine) sample matrices. Each matrix was analysed using 11 different MS methods, with 5–15 variable size acquisition windows. True positive (TP) annotation (i.e., matching experimental and library spectra) rates were constant for PSE (40%) and highest for urine (18%), wastewater (34% and 36%, unpreserved and acidified, respectively) and river water (8%) when using higher numbers of windows (15). The number of annotated features was highest for PSE (12%) and urine (8.5%) when using more acquisition windows (9 and 14, respectively). Less complex matrices (based on average total ion chromatogram intensities) like river water, unpreserved and acidified wastewater have higher annotation rates (7.5%, 8% and 13.2%, respectively) when using less acquisition windows (5–6), indicating matrix dependency of optimum settings. Library scores varied widely for correct (scores between 6 and 100) as well as incorrect annotations (scores between 2 and 100), making it hard to define specific ideal cut-off values. Results highlight the need for properly curated libraries and careful optimization of SWATH-MS and other DIA methods for each individual matrix, finding the best ratio of total annotations to true positive, (i.e., correct) annotations to achieve best NTA results.

The Dynamic Nature of a Static Headspace Above Frozen Leaf Biomass From a Toxic Brazilian Plant

A static headspace method of sampling coupled to a conventional instrumental analytical probe, gas chromatography mass spectrometry (GCMS), has been applied to examine the volatile fraction above leaf tissue from Palicourea marcgravii, a toxic Brazilian plant that causes sudden death in livestock, and two other surrogate species (Lippia alba and Plectranthus spp.). &#x0D; &#x0D; The unusual total ion chromatogram obtained for the plant of interest is discussed and explained by considering the &amp;ldquo;dynamic&amp;rdquo; nature of the static headspace when intact cellular biomass is present and frozen leaves are analyzed concerning the presence and production of methyl salicylate (MeSA), which is this plants main toxin.

Identification and characterization of stress degradation products of ibrutinib by LC-UV/PDA and LC-Q/TOF-MS studies.

The anticancer drug ibrutinib was subjected to stress degradation studies under the ICH-prescribed hydrolytic, photolytic, oxidative and thermal stress conditions, and its degradation behavior was studied. A significant degradation was noted for the drug under acidic/alkaline hydrolytic, acid/alkaline photolytic, and oxidative conditions. The UPLC-UV/PDA studies revealed the generation of six degradation products (I-VI), and these were adequately resolved from the drug under the developed chromatographic conditions over a Kinetex® C18 (100 mm×4.6 mm; 2.6 μm) column employing isocratic elution method. Detection wavelength was selected as 289 nm. The UPLC-UV/PDA method conditions were extrapolated to UPLC-MS/TOF studies. All the six degradation products were found to be ionized in the total ion chromatogram, and the products could be identified and characterized from their mass spectral data. The possible degradation route of ibrutinib leading to generation of various products was also postulated.

Phytochemical Screening of Rhizome Extract of Curcuma longa Linn. Grown in Bangladesh through GC-MS and its Bioactivities

The methanolic extract of Curcuma longa L. rhizome was subjected to Gas Chromatography-Mass Spectrometric (GC-MS) analysis. The chromatographic investigation of the extract showed 27 constituents of which 19 compounds were newly found from C. longa. Here, the peaks obtained in the total ion chromatogram were compared with the National Institute of Standards and Technology (NIST) database for identification of the constituents. The most plentiful component was 9-octadecenamide (Z) (5.93%). The component present in the lowest amount was 4-hydroxy-3-methoxy benzoic acid methyl ester (0.08%). The rhizome extract of C. longa and its six fractions (F1-F6) obtained through vacuum liquid chromatography (VLC) were also investigated for antioxidant, cytotoxic and antimicrobial activities.The crude extract and its fractions (F4-F6) exhibited strong antioxidant activity having IC50 values of 19.85, 18.41, 26.72 and 16.79 μg/ml, respectively compared to the standards butylated hydroxyl anisole (IC50 = 11.42 μg/ml) and ascorbic acid (IC50 = 9.01 μg/ml). Strong cytotoxicity was found in crude extract (LC50 = 1.81 μg/ml) and fractions F4 (LC50 = 2.4 μg/ml), F5 (LC50 = 2.5 μg/ml) and F6 (LC50 = 2.3 μg/ml) when compared to the standard, tamoxifen (LC50 = 0.13 μg/ml). Fractions F1-F3 displayed mild to moderate antibacterial activity against Bacillus megaterium, Staphylococcus aureus and Pseudomonas aeruginosa in comparison with the standard, Kanamycin. The compounds obtained through GC-MS may explain the above activities. The present results showed the prospect of this medicinal plant to explore further to determine the bioactive components. Dhaka Univ. J. Pharm. Sci. 22(1): 11-20, 2023 (June)

Gamma irradiation effect on physicochemical properties of Guazuma ulmifolia leaves and their antiproliferative activities against human cancer cell lines

Guazuma ulmifolia leaves (GUL) has a long been used in traditional medicine, including anticancer. To preserve the simplicia, many companies utilize gamma irradiation techniques. The research aimed to study the irradiation effect on GUL simplicia that preserved using gamma irradiation based on its physicochemical properties and antiproliferative activities against human cancer cell lines. GUL was irradiated at 7.5 kGy, then the irradiated sample (IRGUL) and un-irradiated sample (GUL) as a control were gradually macerated using n-hexane, ethyl acetate, and ethanol. The obtained ethyl acetate extracts from control sample (EAE-GUL) and irradiated samples (EAE-IRGUL) were then fractionated by silica gel column chromatograph using combination of n-hexane/ethyl acetate/methanol. The EAE-GUL, EAE-IRGUL, and its active fraction (fraction 4) were then evaluated their total phenolic and total flavonoid contents (TPC, TFC), thin layer chromatograph-densitometry (TLC-densitometry), LC/MS/MS, as well as in vitro bioassay against human cancer cells (THP1 leukemia, MCF7 breast cancer, and K562 erythroleukemia). The results showed that the n-hexane, ethyl acetate, and ethanol extracts of EAE-IRGUL were lower than these extracts of EAE-GUL. Analysis of TPC, TFC showed that their TPC and TFC of EAE-IRGUL decreased by 15.8% and 4.9%, respectively, compared to EAE-GUL. In vitro bioassay showed that the irradiation dose of 7.5 kGy could decrease their antiproliferative activity of ethyl acetate extracts and their fraction 4 against THP1, MCF7, and K562 cancer cells, however, the decrease did not eliminate their bioactivity. Therefore, good manufacturing practices to obtain low bioburden is important, so the irradiation dose can be kept as low as possible. In addition, increasing the active ingredient dosage may be applied with regard to the decrease in physicochemical and biological properties of GUL simplicia due to irradiation exposure. TLC-densitometry and LC/MS/MS analysis showed that some main spots on TLC and main peaks at total ion chromatogram (TIC) of F4 of EAE-IRGUL decreased, while other spots on TLC and peaks in TIC increased compared to control. More studies are needed to evaluate the effect of gamma radiation on individual compounds using chromatographic techniques and NMR as well.

GC/MS and DART-MS as complementary methods for investigating the effects of weathering on chemical profiles of ignitable liquids: A case study for paint thinner

In this study, gas chromatography/mass spectrometry (GC/MS) and direct analysis in real time mass spectrometry (DART-MS) were used to analyze paint thinner samples weathered under different conditions. As GC/MS total ion chromatograms (TIC) of weathered paint thinner samples varied significantly due to the disparate evaporation rates of organic compounds in the mixture, DART-MS spectra have shown more consistent profiles among different samples. The distinctive ion clusters identified in the DART-MS spectra were attributed to the less volatile glycol ethers and polymeric compounds with alkyl chains in the paint thinner samples. Analysis of variance-principal component analysis (ANOVA-PCA) was applied to study the contributions of weathering degree and temperature factors to the total variance of GC/MS TIC and DART-MS spectral datasets and found that both factors played significant roles in the weathering process (p < 0.05), though weathering degree contributed to considerably more total variance to GC/MS TIC profiles (i.e., 93.4%). The paint thinner GC/MS and DART-MS profiles were compared with those from other common ignitable liquids, such as gasoline, torch fuel, lighter fluid, and Japan drier. The partial least squares discriminant analysis (PLS-DA) models were constructed to classify the ignitable liquids with the classification rates of 99.97 ± 0.02% and 99.80 ± 0.08% for models based on GC/MS and DART-MS data, respectively. Our study has shown that DART-MS can provide discriminative information for distinguishing ignitable liquid samples and complement the existing GC/MS method by the detection of less volatile compounds.

Qingda granule ameliorates vascular remodeling and phenotypic transformation of adventitial fibroblasts via suppressing the TGF-β1/Smad2/3 pathway

Ethnopharmacological relevanceQingda granule (QDG) exhibits significant therapeutic effects on high blood pressure, vascular dysfunction, and elevated proliferation of vascular smooth muscle cells by inhibiting multiple pathways. However, the effects and underlying mechanisms of QDG treatment on hypertensive vascular remodeling are unclear. Aim of the studyThe aim of this study was to determine the role of QDG treatment in hypertensive vascular remodeling in vivo and in vitro. Materials and methodsAn ACQUITY UPLC I-Class system coupled with a Xevo XS quadrupole time of flight mass spectrometer was used to characterize the chemical components of QDG. Twenty-five spontaneously hypertensive rats (SHR) were randomly divided into five groups, including SHR (equal volume of double distilled water, ddH2O), SHR + QDG-L (0.45 g/kg/day), SHR + QDG-M (0.9 g/kg/day), SHR + QDG-H (1.8 g/kg/day), and SHR + Valsartan (7.2 mg/kg/day) groups. QDG, Valsartan, and ddH2O were administered intragastrically once a day for 10 weeks. For the control group, ddH2O was intragastrically administered to five Wistar Kyoto rats (WKY group). Vascular function, pathological changes, and collagen deposition in the abdominal aorta were evaluated using animal ultrasound, hematoxylin and eosin and Masson staining, and immunohistochemistry. Isobaric tags for relative and absolute quantification (iTRAQ) was performed to identify differentially expressed proteins (DEPs) in the abdominal aorta, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed. Cell Counting Kit-8 assays, phalloidin staining, transwell assays, and western-blotting were performed to explore the underlying mechanisms in primary isolated adventitial fibroblasts (AFs) stimulated with transforming growth factor-β 1 (TGF-β1) with or without QDG treatment. ResultsTwelve compounds were identified from the total ion chromatogram fingerprint of QDG. In the SHR group, QDG treatment significantly attenuated the increased pulse wave velocity, aortic wall thickening, and abdominal aorta pathological changes and decreased Collagen I, Collagen III, and Fibronectin expression. The iTRAQ analysis identified 306 DEPs between SHR and WKY and 147 DEPs between QDG and SHR. GO and KEGG pathway analyses of the DEPs identified multiple pathways and functional processes involving vascular remodeling, including the TGF-β receptor signaling pathway. QDG treatment significantly attenuated the increased cell migration, actin cytoskeleton remodeling, and Collagen I, Collagen III, and Fibronectin expression in AFs stimulated with TGF-β1. QDG treatment significantly decreased TGF-β1 protein expression in abdominal aortic tissues in the SHR group and p-Smad2 and p-Smad3 protein expression in TGF-β1-stimulated AFs. ConclusionsQDG treatment attenuated hypertension-induced vascular remodeling of the abdominal aorta and phenotypic transformation of adventitial fibroblasts, at least partly by suppressing TGF-β1/Smad2/3 signaling.

SHS-GC-MS applied in Coffea arabica and Coffea canephora blend assessment.

Considering the great economic significance of Coffea arabica (arabica) associated with the lower production cost of C. canephora (conilon), blends of these coffees are commercially available to reduce costs and combine sensory attributes. Thus, analytical tools are required to ensure consistency between real and labeled compositions. In this sense, chromatographic methods based on volatile analysis using static headspace-gas chromatography-mass spectrometry (SHS-GC-MS) and Fourier transform infrared (FTIR) spectroscopy associated with chemometric tools were proposed for the identification and quantification of arabica and conilon blends. The peak integration from the total ion chromatogram (TIC) and extracted ion chromatogram (EIC) was compared in multivariate and univariate scenarios. The optimized partial least squares (PLS) models with uninformative variable elimination (UVE) and chromatographic data (TIC and EIC) have similar accuracy according to a randomized test, with prediction errors between 3.3% and 4.7% and Rp2 > 0.98. There was no difference between the univariate models for the TIC and EIC, but the FTIR model presented a lower performance than GC-MS. The multivariate and univariate models based on chromatographic data had similar accuracy. For the classification models, the FTIR, TIC, and EIC data presented accuracies from 96% to 100% and error rates from 0% to 5%. Multivariate and univariate analyses combined with chromatographic and spectroscopic data allow the investigation of coffee blends.

Factorial design applied to LC-ESI-QTOF mass spectrometer parameters for untargeted metabolomics.

Investigations of untargeted metabolomics are based on high-quality data acquisition usually from multiplatform systems that include high-resolution mass spectrometry equipment. The comprehensive set of results is used as data entry for bioinformatics and machine learning sciences to access reliable metabolic and biochemical information for clinical, forensic, environmental, and endless applications. In this context, design of experiments is a powerful tool for optimizing data acquisition procedures, using a multivariate approach, which enables the maximization of a high-quality amount of information with reduced number of tests. In this study, we applied a 33 Box-Behnken factorial design with central point triplicate for optimizing the ionization of an HPLC-ESI-QTOF method used for screening urine samples. Nozzle voltage (V), fragmentor voltage (V) and nebulizer pressure (psig) were the factors selected for variation. The response surface methodology was applied in the molecular features extracted at each level, resulting in a statistical model that helps evaluating the synergic interaction between these factors. Together with the qualitative analysis of the resulting total ion chromatograms, we came across a reproducible (6.14% RSD) and highly efficient method for untargeted metabolomics of human urine samples. The proposed method can be useful for applications in several urine-based metabolomics-driven studies, as the factorial design can be applied in the development of any analytical protocol considering different LC-MS setups.

Carbon Dioxide Microbubble Bursting Ionization Mass Spectrometry.

Aerosols generated by bubble bursting have been proved to promote the extraction of analytes and have ultrahigh electric fields at their water-air interfaces. This study presented a simple and efficient ionization method, carbon dioxide microbubble bursting ionization (CDMBI), without the presence of an exogenous electric field (namely, zero voltage), by simulating the interfacial chemistries of sea spray aerosols. In CDMBI, microbubbles are generated in situ by continuous input of carbon dioxide into an aqueous solution containing low-concentration analytes. The microbubbles extract low- and high-polarity analytes as they pass through the aqueous solution. Upon reaching the water-air interface, these microbubbles burst to produce charged aerosol microdroplets with an average diameter of 260 μm (8.1-10.4 nL in volume), which are immediately transferred to a mass spectrometer for the detection and identification of extracted analytes. The above analytical process occurs every 4.2 s with a stable total ion chromatogram (relative standard deviation: 9.4%) recorded. CDMBI mass spectrometry (CDMBI-MS) can detect surface-active organic compounds in aerosol microdroplets, such as perfluorooctanoic acid, free fatty acids epoxidized by bubble bursting, sterols, and lecithins in soybean and egg, with the limit of detection reaching the level of fg/mL. In addition, coupling CDMBI-MS with an exogenous voltage yields relatively weak gains in ionization efficiency and sensitivity of analysis. The results suggested that CDMBI can simultaneously accomplish both bubbling extraction and microbubble bursting ionization. The mechanism of CDMBI involves bubbling extraction, proton transfer, inlet ionization, and electrospray-like ionization. Overall, CDMBI-MS can work in both positive and negative ion modes without necessarily needing an exogenous high electric field for ionization and quickly detect trace surface-active analytes in aqueous solutions.