Liquid Chromatography-electrospray Mass Research Articles

Spatial distribution of differential metabolites in different parts of Tetrastigma hemsleyanum Diels et Gilg by ultrahigh-performance liquid chromatography/mass spectrometry and desorption electrospray ionization mass spectrometry imaging

Tetrastigma hemsleyanum Diels et Gilg (T. hemsleyanum) is a homology medicine and food that is rich in bioactive ingredients such as flavonoids and phenolic acids. A strategy that integrates ultrahigh-performance liquid chromatography–electrospray ionization mass spectrometry (UHPLC–ESI/MS) and desorption electrospray ionization mass spectrometry imaging (DESI-MSI) spatial metabolomics analysis was proposed and applied to different parts of T. hemsleyanum for the first time. A total of 132 compounds were tentatively identified, and 3, 7, and 24 components were found only in tuberous roots (TRs), fibrous roots (FRs), and leaves, respectively, using UHPLC–ESI/MS. The DESI-MSI results showed that the spatial distribution of flavonoids between the aerial and underground parts was diverse; for example, vitexin-2″-O-glucoside was largely localized in the epidermis and xylem of TRs, while a small amount was restricted to the xylem of the leaf margin and FRs. There was a higher abundance of most organic acids and flavonoids in the leaves than in the underground parts. Some flavonoids showed the same abundance in FRs and TRs, but the levels of most compounds were considerably higher in FRs. It is possible for leaves and FRs to become new medicinal parts of T. hemsleyanum. Through chemometrics statistics analysis, 19 key differential compounds in different parts of T. hemsleyanum were found, and the pharmacological mechanisms of the main differential metabolites were predicted by network pharmacology. This study provides a novel method for the medicinal development of T. hemsleyanum, showing its great potential in the development of medicinal resources.

Proteomic Analysis of Dorsal Root Ganglia in a Mouse Model of Paclitaxel-Induced Neuropathic Pain.

Paclitaxel is a chemotherapy drug widely used for the treatment of various cancers based on its ability to potently stabilize cellular microtubules and block division in cancer cells. Paclitaxel-based treatment, however, accumulates in peripheral system sensory neurons and leads to a high incidence rate (over 60%) of chemotherapy induced peripheral neuropathy. Using an established preclinical model of paclitaxel-induced peripheral neuropathy (PIPN), we examined proteomic changes in dorsal root ganglia (DRG) of adult male mice that were treated with paclitaxel (8 mg/kg, at 4 injections every other day) relative to vehicle-treated mice. High throughput proteomics based on liquid chromatography electrospray ionization mass spectrometry identified 165 significantly altered proteins in lumbar DRG. Gene ontology enrichment and bioinformatic analysis revealed an effect of paclitaxel on pathways for mitochondrial regulation, axonal function, and inflammatory purinergic signaling as well as microtubule activity. These findings provide insight into molecular mechanisms that can contribute to PIPN in patients.

Food authentication goes green: Determination of the geographical origin of grain maize (Zea mays L.) using direct analysis in real time mass spectrometry (DART-MS)

Time savings, environmental friendliness and cost reduction are important criteria to determine the authenticity of feed and food in routine analysis. One analytical technique that is especially promising in terms of these criteria in metabolomics studies is Direct Analysis in Real Time Mass Spectrometry (DART-MS). In the present study, DART-MS is applied to 200 grain maize samples from seven geographical origins to develop a data processing workflow and an approach for origin analysis of grain maize. For the first time, such a large sample set was investigated using a DART-MS-based non-targeted lipidomics approach. Various open-source programs were used for pre-processing and random forest (RF) combined with repeated cross-validation was used for classification, resulting in an accuracy of 84.4%. Subsequently, the most important markers identified by RF, belonging to the classes of mono-, di- and triacylglycerols, were identified using DART-MS2. The chosen method significantly minimizes the time and solvent consumption compared to classic liquid chromatography electrospray ionization mass spectrometric (LC-ESI-MS) strategies and thus offers a more cost-effective and environmentally friendly alternative. Furthermore, the results show the high potential for determining the geographical origin of grain maize using DART-MS.

Green synthesis and characterization of silver nanoparticles from Ducrosia flabellifolia Boiss. aqueous extract: Anti-quorum sensing screening and antimicrobial activities against ESKAPE pathogens.

Biosynthesis of silver nanoparticles using natural compounds derived from plant kingdom is currently used as safe and low-cost technique for nanoparticles synthesis with important abilities to inhibit multidrug resistant microorganisms (MDR). ESKAPE pathogens, especially MDR ones, are widely spread in hospital and intensive care units. In the present study, AgNPs using Ducrosia flabellifolia aqueous extract were synthesized using a reduction method. The green synthesized D. flabellifolia-AgNPs were characterized by UV-Vis spectrophotometer, Scanning electron microscopy (SEM), and X-ray diffraction assays. The tested D. flabellifolia aqueous extract was tested for its chemical composition using Liquid Chromatography-Electrospray Ionization-Mass Spectrometry (LC-ESI-MS). Anti-quorum sensing and anti-ESKAPE potential of D. flabellifolia-AgNPs was also performed. Results from LC-ESI-MS technique revealed the identification of chlorogenic acid, protocatechuic acid, ferulic acid, caffeic acid, 2,5-dihydroxybenzoic acid, and gallic acid as main phytoconstituents. Indeed, the characterization of newly synthetized D. flabellifolia-AgNPs revealed spherical shape with mean particle size about 16.961±2.914 nm. Bio-reduction of silver was confirmed by the maximum surface plasmon resonance of D. flabellifolia-AgNPs at 430 nm. Newly synthetized D. flabellifolia-AgNPs were found to possess important anti-ESKAPE activity with low minimal inhibitory concentrations (MICs) ranging from 0.078 to 0.312 mg/mL, and low minimal bactericidal concentrations (MBCs) varying from 0.312 to 0.625 mg/mL. Moreover, D. flabellifolia-AgNPs were active against Candida utilis ATCC 9255, C. tropicalis ATCC 1362, and C. albicans ATCC 20402 with high mean diameter of growth inhibition at 5 mg/mL, low MICs, and minimal fungicidal concentrations values (MFCs). The newly synthetized D. flabellifolia-AgNPs were able to inhibit violacein production in Chromobacterium violaceum, pyocyanin in Pseudomonas aeruginosa starter strains. Hence, the newly synthesized silver nanoparticles using D. flabellifolia aqueous extract can be used as an effective alternative to combat ESKAPE microorganisms. These silver nanoparticles can attenuate virulence of Gram-negative bacteria by interfering with the quorum sensing system and inhibiting cell-to-cell communication.

Development and Validation of Derivatization Method for Simultaneous Quantitation of Asteracantha longifolia (L.) Nees Phytoconstituents by Liquid Chromatography–Electrospray Ionization–Mass Spectrometry/Mass Spectrometry

ABSTRACT Background: Betulin, lupeol, stigmasterol, and β-sitosterol are the active phytoconstituents accountable for the practical application of Asteracantha longifolia (L.) Nees in ayurvedic treatments as antitumor, hypoglycemic, aphrodisiac, antibacterial, free radical scavenging, lipid peroxidation, and hepatoprotective agent. As an essential medicinal plant in modern and traditional medicine, regularly checking raw material’s quality attributes and quantifying the phytoconstituents is indispensable. Aim: The aim of this study was to optimize derivatization conditions of these four essential phytoconstituents with p-toluenesulfonyl isocyanate (PTSI) reagent and the development of a liquid chromatography–electrospray ionization (ESI)–mass spectrometry (MS)/MS method that aids in the simultaneous detection of these four phytoconstituents. Objective: Thus, derivatization enhances sensitivity for detection in the negative mode with an electron spray ionization source and tandem mass spectroscopy. Further, the sensitive and rapid analytical method for simultaneous quantitation of betulin, lupeol, stigmasterol, and β-sitosterol is subsequently validated in line with the guidelines by ICH and used to quantify the phytoconstituents in two over-the-counter herbal formulations and one plant extract isolated at laboratory scale under batch analysis. Materials and Methods: PTSI reagent of purity <98% procured from TCI and other chromatography reagents of MS grade were utilized in the optimization of an analytical method. Results: The developed LC-ESI-MS/MS-based method demonstrated specificity for the targeted phytoconstituents, with LOD and LOQ values of < 0.13 ng/mL and 0.4 ng/mL, respectively. Linearity was established with a correlation coefficient ≥ 0.998 over a concentration range of 0.2 ng/mL to 6 ng/mL. Precision, expressed as %RSD for peak response, was ≤ 5%. The method showed satisfactory recovery for betulin (98.5%-108.3%), lupeol (95.0%-109.3%), stigmasterol (101.9%-117.0%), and β-sitosterol (99.1%-116.2%). Conclusion: The reagent PTSI reacts rapidly and forms stable derivatives. The derivatization of active phytoconstituents betulin, lupeol, stigmasterol, and β-sitosterol has enhanced the detection sensitivity of the analytical method.

Streamlined Arsenolipid Identification via Direct Arsenic Detection Using RPLC-ESI-QTOF-MS with Collision-Induced Dissociation.

Arsenolipids are organoarsenicals with a long aliphatic chain that have been identified in a wide array of marine organisms. Precise analysis of arsenolipids is crucial for evaluating their toxicity, ensuring food safety, monitoring the environment, and gaining insights into the evolution of arsenic biogeochemistry. However, the discovery of new arsenolipids is often impeded by existing analytical challenges, notably the need for multiple instruments, such as the combination of liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS) and inductively coupled plasma mass spectrometry (LC-ICP-MS). This study introduces a high-throughput untargeted analytical method on the basis of an unsophisticated instrumental configuration, LC-ESI-MS with collision-induced dissociation (CID) at 200 eV. This approach provides efficient dissociation of arsenic atoms from their precursor lipids and direct detection of the organic-bound arsenic as monatomic cations, As+. Application of this method has shown promise in rapidly characterizing arsenolipids in diverse samples, which has led to the discovery of a wide range of novel arsenolipids, including seven previously unidentified thioxoarsenolipids in ancient marine sediments.

Geographical distribution-based differentiation of cultivated Angelica dahurica, exploring the relationship between the secretory tract and the quality

Based on geographical distribution, cultivated Chinese Angelica dahurica has been divided into Angelica dahurica cv. ‘Hangbaizhi’ (HBZ) and Angelica dahurica cv. ‘Qibaizhi’ (QBZ). Long-term geographical isolation has led to significant quality differences between them. The secretory structure in medicinal plants, as a place for accumulating effective constituents and information transmission to the environment, links the environment with the quality of medicinal materials. However, the secretory tract differences between HBZ and QBZ has not been revealed. This study aimed to explore the relationship between the secretory tract and the quality of two kinds of A. dahurica. Root samples were collected at seven development phases. High-Performance Liquid Chromatography (HPLC) and Desorption Electrospray Ionization Mass Spectrometry Imaging (DESI-MSI) were used for the content determination and spatial location of coumarins. Paraffin section was used to observe and localize the root secretory tract. Origin, CaseViewer, and HDI software were used for data analysis and image processing. The results showed that compared to QBZ, HBZ, with better quality, has a larger area of root secretory tracts. Hence, the root secretory tract can be included in the quality evaluation indicators of A. dahurica. Additionally, DESI-MSI technology was used for the first time to elucidate the temporal and spatial distribution of coumarin components in A. dahurica root tissues. This study provides a theoretical basis for the quality evaluation and breeding of improved varieties of A. dahurica and references the DESI-MSI technology used to analyze the metabolic differences of various compounds, including coumarin and volatile oil, in different tissue parts of A. dahurica.

Antifungal peptides from faba bean flour fermented by Levilactobacillus brevis AM7 improve the shelf-life of composite faba-wheat bread

Faba bean is an important crop from an ecological, nutritional, and economical perspective, hence its incorporation in plant-based products can play a key role in the sustainability of the whole food system. In this study, the antifungal properties of faba bean flour were investigated employing three bioprocessing treatments including hydrolysis with a commercial proteolytic enzyme preparation, and fermentation with selected or commercial mixed sourdough starters. Faba bean flour fermented by Levilactobacillus brevis AM7 showed the broadest inhibitory spectrum against the fungal species tested and antifungal activity ranging from 25 to 73 %. Bioactive proteins and peptides were found to be responsible for the antifungal activity. Polypeptides sequences corresponding to defensin-like and non-specific lipid-transfer proteins and seven antifungal peptides having 11–22 amino acid residues and mass from 1240.7 to 2624.2 Da, were identified via Liquid Chromatography-Electrospray Ionisation-Mass Spectra/Mass Spectra (nano-LC-ESI-MS/MS). To assess the antifungal effect in food processing conditions, fermented faba bean was used as ingredient in breadmaking at a substitution level of 30 % of the dough weight. Wheat composite-bread containing faba bean sourdough, which could be claimed as “source of proteins”, according to the current EC Regulation, delayed the molds contamination, lasting up to 10 days before mold appearance, and behaving similarly to wheat bread containing calcium propionate.

Immunoglobulin A Glycosylation Differs between Crohn's Disease and Ulcerative Colitis.

Inflammatory bowel diseases (IBD), such as Crohn's disease (CD) and ulcerative colitis (UC), are chronic and relapsing inflammations of the digestive tract with increasing prevalence, yet they have unknown origins or cure. CD and UC have similar symptoms but respond differently to surgery and medication. Current diagnostic tools often involve invasive procedures, while laboratory markers for patient stratification are lacking. Large glycomic studies of immunoglobulin G and total plasma glycosylation have shown biomarker potential in IBD and could help determine disease mechanisms and therapeutic treatment choice. Hitherto, the glycosylation signatures of plasma immunoglobulin A, an important immunoglobulin secreted into the intestinal mucin, have remained undetermined in the context of IBD. Our study investigated the associations of immunoglobulin A1 and A2 glycosylation with IBD in 442 IBD cases (188 CD and 254 UC) and 120 healthy controls by reversed-phase liquid chromatography electrospray-ionization mass spectrometry of tryptic glycopeptides. Differences of IgA O- and N-glycosylation (including galactosylation, bisection, sialylation, and antennarity) between patient groups were associated with the diseases, and these findings led to the construction of a statistical model to predict the disease group of the patients without the need of invasive procedures. This study expands the current knowledge about CD and UC and could help in the development of noninvasive biomarkers and better patient care.

Eremophila purpurascens: Anti-oxidant, Anti-hyperglycemic, and Hepatoprotective Potential of Its Polyphenolic Rich Leaf Extract and Its LC-ESI-MS/MS Chemical Characterization and Standardization.

The genus Eremophila, despite comprising more than 250 species, has scarce literature studies that could be traced concerning the chemical profile and bioactivity of Eremophila purpurascens. The current study targets the investigation of the in vitro and in vivo anti-oxidant, anti-hyperglycemic, and hepatoprotective potential of the polyphenol-rich leaf extract of E. purpurascens (EP). EP showed promising total anti-oxidant capacity with IC50 values of 106 and 114 μg/mL in 2,2'-azinobis [3-ethylbenzothiazoline-6-sulfonic acid]-diammonium salt (ABTS) and diphenyl-1-picrylhydrazyl (DPPH) assays, respectively, with total anti-oxidant capacities of 331, 245, and 1767 μmol/g in ABTS, DPPH, and ferric reducing anti-oxidant power assays, respectively. In HepG2 cells, pre-treated with CCl4, a dose of 100 μg/mL EP ameliorated the reduced superoxide dismutase and glutathione levels and total anti-oxidant capacity with values of 312.5 U/mL, 15.47 mg/dL, and 1.03 nmol/mL, respectively. In vitro anti-diabetic evaluation using 3T3-L1 adipocyte culture showed that at a dose of 30 μg/mL, the EP extract elicited a 6.3% decrease in the concentration of glucose (22.4 mmol/L), showing significant amelioration with regard to pioglitazone and insulin. EP also demonstrated elevated serum insulin by 77.78% with a marked reduction in fasting blood glucose level by 64.55% relative to the streptozotocin diabetic rats in vivo. EP also relieved the liver stress markers both in vitro in CCl4 and in vivo in tamoxifen (TAM) models. EP markedly decreased TAM toxicity, as demonstrated by the decline in the liver stress markers, ALT and AST, by 36.1 and 51.1%, respectively. It also relieved the oxidative stress triggered by TAM, as revealed by the reduction in the levels of TBARs and TNF-α by 21.4 and 40%, respectively. Liquid chromatography electrospray ionization mass spectrometry of EP revealed a total of twelve peaks belonging to phenylpropanoids, lignans, and phenolics, where verbascoside and pinoresinol-4-O-β-d-glucoside represented the most abundant secondary metabolites. The docking experiment showed that tri-O-galloyl-hexoside had the best fitting within the NADPH oxidase active sites with binding energy (ΔG = -81.12 kcal/mol). Thus, the plant can be of beneficial value in the control of hyperglycemia in diabetic patients, besides its prophylactic potential against hepatic complications.

Production and characterization of a novel poly amino acid from a thermophilic bacterium, and preliminary testing of its coagulating potential for imminent wastewater treatment application

The increasing demand for biopolymers across diverse fields, such as food, medicine, cosmetics, and environmental applications, has prompted researchers to explore novel molecules with enhanced functionalities that meet these demands. In this study, a thermophilic strain of Bacillus licheniformis was employed to produce a unique polyamino acid. This thermophilic isolate exhibited rapid growth at 50 °C in a sucrose mineral salts medium, resulting in a biopolymer concentration of 7.4 g/L. Interestingly, the biopolymer produced at different temperatures exhibited varying glass-transition temperatures (ranging from 87.86 °C to 104.11 °C) and viscosities (7.5 cP to 16.3 cP), suggesting that the fermentation temperature significantly influenced the degree of polymerization. Furthermore, the biopolymer was characterized using various techniques, including Thin Layer Chromatography (TLC), Fourier Transform Infrared (FTIR) spectroscopy, Liquid Chromatography-Electrospray Ionization-Mass Spectroscopy (LC-ESI MS), Nuclear Magnetic Resonance (NMR), and Differential Scanning Calorimetry-Thermogravimetric Analysis (DSC-TGA). The results revealed that the obtained biopolymer was a poly amino acid, with poly-γ-glutamic acid as the major monomeric component in the polymer backbone with a few appendages of aspartic acid residues in its side chain. Finally, the biopolymer demonstrated significant coagulation potential for water treatment applications, as evidenced by coagulation studies conducted under varying pH conditions using kaolin-clay as a model precipitant.

Polybutylene terephthalate-based stationary phase for ion-pair-free reversed-phase liquid chromatography of small interfering RNA. Part 2: Use for selective comprehensive two-dimensional liquid chromatography

With the increasing numbers of nucleic acid-based pharmaceuticals like antisense oligonucleotides (ASO), small interfering ribonucleic acid (siRNA) entering the market, research facilities, pharmaceutical industries and also regulatory authorities have been looking for efficient analytical methods for these synthetic oligonucleotides (ON). Besides of conventional one-dimensional (1D) reversed-phase liquid chromatography with or without ion-pairing (IP-RP-LC, RP-LC), hydrophilic liquid chromatography (HILIC) and mixed-mode chromatography (MMC), two-dimensional (2D) approaches combining two orthogonal chromatographic techniques also become more relevant due to the high structural complexity of oligonucleotides. Recently, we tested a polybutylene terephthalate(PBT)-based stationary phase under ion-pairing free RP mode for the liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS) analysis of siRNA (Patisiran). In this study, retention profile and chromatographic orthogonality, respectively, were compared to other LC-modes like HILIC, IP-RPLC, another ion-pair free cholesterol-bonded RPLC and MMC considering their normalized retention times. Finally, because of higher orthogonality, the ion-pairing free PBT-bonded RPLC as first dimension (1D) was hyphenated with HILIC in the second dimension (2D) in a selective comprehensive 2D-LC setup leading to an enhanced resolution for peak purity evaluation of the main ON entities.

Widespread occurrence of in-source fragmentation in the analysis of natural compounds by LC-ESI-MS.

The In-Source Fragmentation (ISF) of analyte or co-eluting substances produces unintentional fragment ions, which hampers the identification and quantification by liquid chromatography-mass spectrometry (LC-MS). Natural compounds derived from plants also contain fragile moieties that may undergo ISF. However, the characteristics of ISF of natural compounds in LC-MS are still unclear. The ISF behavior of 214 natural compounds was assayed in liquid chromatography-Q/orbitrap mass spectrometry in electrospray ionization mode (ESI) and the extent of ISF was evaluated. Up to 82% of tested compounds undergo ISF and half of the tested natural compounds that contain more than one fragile moiety underwent successive and severe ISF to generate serial structurally-related ISF products. The major ISF-altering moieties for natural compounds were hydroxyl, lactone, glycosyl, and ether, resulting in neutral loss of H2 O or CO, deglycosylation, or cleavage of ether bond, respectively. Some compounds such as terpenoids undergo severe ISF and less than 1% parent form can be observed. For natural compounds, the ISF product with similar structures more likely to cause interference in analysis because the ISF products may share identical mass-to-charge ratio and similar MS2 fragmentation patterns with precursor ions of the homologs in plants. Furthermore, the severe ISF may cause a false negative in the identification of the parent form. In summary, ISF was a highly frequent phenomenon for analysis of natural compounds by LC-ESI-MS, extensive and successive ISF of natural products may cause misannotation and misidentification with the homologs in plants. It should raise awareness of ISF interference during the analysis of natural compounds.

BaoShenTongLuo formula protects against podocyte injury by regulating AMPK-mediated mitochondrial biogenesis in diabetic kidney disease

BackgroundMitochondrial dysfunction is considered to be an important contributor in podocyte injury under diabetic conditions. The BaoShenTongLuo (BSTL) formula has been shown to reduce podocyte damage and postpone the progression of diabetic kidney disease (DKD). The potential mechanisms underlying the effects of BSTL, however, have yet to be elucidated. In this study, we aimed to investigate whether the effects of BSTL are related to the regulation of mitochondrial biogenesis via the adenosine monophosphate-activated protein kinase (AMPK) pathway.MethodsHigh-Performance Liquid Chromatography Electrospray Ionization Mass Spectrometer (HPLC–ESI–MS) analysis was performed to investigate the characteristics of pure compounds in BSTL. db/db mice and mouse podocyte clone-5 (MPC5) cells were exposed to high glucose (HG) to induce DKD and podocyte damage. Body weight, random blood glucose, urinary albumin/creatinine ratio (UACR), indicators of renal function and renal histological lesions were measured. Markers of podocyte injury, mitochondrial morphology, mitochondrial deoxyribonucleic acid (mtDNA) content, mitochondrial respiratory chain complexes activities, reactive oxygen species (ROS) production, and mitochondrial membrane potential (MMP) levels were assessed. Protein expressions of AMPK, peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α), transcription factor A (TFAM), mitochondrial fusion protein 2 (MFN2) and dynamin-related protein 1 (DRP1) were also detected. MPC5 cells were transfected with AMPKα small interfering RNA (AMPKα siRNA) to determine the underlying mechanisms of BSTL improvement of mitochondrial function under diabetic conditions.ResultsIn vivo, treatment with BSTL reduced the UACR levels, reversed the histopathological changes in renal tissues, and alleviated the podocyte injury observed in db/db mice. After BSTL treatment, the decreased mtDNA content and mitochondrial respiratory chain complex I, III, and IV activities were significantly improved, and these effects were accompanied by maintenance of the protein expression of p-AMPKαT172, PGC-1α, TFAM and MFN2. The in vitro experiments also showed that BSTL reduced podocyte apoptosis, suppressed excessive cellular ROS production, and reversed the decreased in MMP that were observed under HG conditions. More importantly, the effects of BSTL in enhancing mitochondrial biogenesis and reducing podocyte apoptosis were inhibited in AMPKα siRNA-treated podocytes.ConclusionBSTL plays a crucial role in protecting against podocyte injury by regulating the AMPK-mediated mitochondrial biogenesis in DKD.

In-vitro and in-vivo anti-leishmanial activity of the hanging sedge flavonoids based on bio- guided fractionation assay.

As a major public health issue, cutaneous leishmaniasis (CL) has a number of complications, including drug resistance and poor response to conventional treatments. Over the last decade, research on natural sources for finding new anti-leishmanial agents has been a critical part of tropical disease research. Natural products also should be regarded as one of the most valuable applications for CL infection drug development. In this study, we assessed the in-vitro and in-vivo anti-leishmanial potential of Carex pendula Huds. (hanging sedge) methanolic extract and its fractions against Leishmania major produced cutaneous infection. Although the methanolic extract and its fractions exhibited suitable activity, the ethyl acetate fraction showed the best activity (with the half maximal inhibitory concentration IC50 = 1.627±0.211 mg/mL). The toxicity and selectivity indices (SI) of all samples were determined in murine peritoneal macrophage cells (J774A.1) using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test. The flavonoid components of the ethyl acetate fraction were identified using liquid chromatography electrospray ionization mass spectrometry (LC-ESI MS/MS). Nine chemical compounds were identified in this fraction, including three flavonols, four flavanonols, and two flavan derivatives. L. major infected mice were used as an in-vivo model because the methanolic extract was effective against L. major promastigotes in the mammalian cell line J774A.1 with SI=2.514 (tail lesion size model). In-silico analysis of identified compounds also revealed a favorable interaction between compounds 2-5 and L. major protein targets (3UIB, 4JZX, 4JZB, 5L4N, 5L42). According to the findings of this study, the ethyl acetate fraction (as flavonoid fraction) exhibited considerable in-vitro anti-leishmanial activity.

Assessing the Effectiveness of Chemical Marker Extraction from Amazonian Plant Cupuassu (Theobroma grandiflorum) by PSI-HRMS/MS and LC-HRMS/MS.

Employing a combination of liquid chromatography electrospray ionization and paper spray ionization high-resolution tandem mass spectrometry, extracts from cupuassu (Theobroma grandiflorum) pulp prepared with either water, methanol, acetonitrile or combinations thereof were subjected to metabolite fingerprinting. Among the tested extractors, 100% methanol extracted preferentially phenols and cinnamic acids derivatives, whereas acetonitrile and acetonitrile/methanol were more effective in extracting terpenoids and flavonoids, respectively. And while liquid chromatography- mass spectrometry detected twice as many metabolites as paper spray ionization tandem mass spectrometry, the latter proved its potential as a screening technique. Comprehensive structural annotation showed a high production of terpenes, mainly oleanane triterpene derivatives. of the mass spectra Further, five major metabolites with known antioxidant activity, namely catechin, citric acid, epigallocatechin-3'-glucuronide, 5,7,8-trihydroxyflavanone, and asiatic acid, were subjected to molecular docking analysis using the antioxidative enzyme peroxiredoxin 5 (PRDX5) as a model receptor. Based on its excellent docking score, a pharmacophore model of 5,7,8-trihydroxyflavanone was generated, which may help the design of new antioxidants.

Structure Determination of Felodipine Photoproducts in UV-Irradiated Medicines Using ESI-LC/MS/MS

Dihydropyridine drugs are well known as photodegradable pharmaceuticals. Herein, we evaluate the photostability of felodipine (FL) medicine (Splendil® (SPL) tablets) and its altered forms (powders and suspensions). FL is a type of dihydropyridine drug, but its photochemical behavior is unknown. FL contents after ultraviolet light (UV) irradiation for 24 h were monitored using high-performance liquid chromatography (HPLC). Values of the residual amounts of FL in UV-irradiated SPL powders and suspensions were 32.76 ± 4.88% and 0.79 ± 0.74%, respectively, with the generation of two photoproducts (FL photoproduct 1 and 2). To identify the chemical structures of these photoproducts, electrospray ionization liquid chromatography mass spectrometry (ESI-LC/MS/MS) analysis was performed. Based on their mass-to-charge ratio values and fragment patterns, it was proposed that FL photoproduct 1 was a pyridine derivative and FL photoproduct 2 was an FL dimer. Interestingly, generation rates of FL photoproduct 1 and 2 were dependent on the presence of the aqueous media. The photodimerization of FL was induced in UV-irradiated SPL suspensions. This is the first report evaluating the photostability of SPL tablets and its altered forms and estimating FL photoproducts induced by UV irradiation in the formulation of SPL.

Hydrophilic interaction liquid chromatography–electrospray ionization mass spectrometry combined with fabric phase sorptive extraction for therapeutic drug monitoring of pioglitazone, repaglinide, and nateglinide in human plasma

Polypharmacy in type 2 diabetes is an issue of major concern as the prescription of multiple medi-cations for the management of diabetes-associated comorbidities can lead to drug-to-drug interactions, which can pose serious risks to patients’ health. Within this context, the development of bioanalytical methods for monitoring the therapeutic levels of antidiabetic drugs is notably useful to ensure patients’ safety. In the present work, a liquid chromatography–mass spectrometry method for the quantitation of pioglitazone, repaglinide, and nateglinide in human plasma is described. Sample preparation was performed by fabric phase sorptive extraction (FPSE), and hydrophilic interaction liquid chromatography (HILIC) was implemented for the chromatographic separation of the analytes, using a ZIC®-cHILIC analytical column (150 × 2.1 mm, 3 µm) under isocratic elution. The mobile phase consisted of 10 mM ammonium formate aqueous solution (pH = 6.5)/ acetonitrile, 10/90 v/v, and was pumped at a flow rate of 0.2 mL min−1. Design of Experiments was used during the development of the sample preparation method to gain deeper insight into the effect of various experimental parameters on extraction efficiency, their potential interactions and to optimize the recovery rates of the analytes. The linearity of the assay was assessed over the ranges of 25 to 2000, 6.25 to 500, and 125 to 10000 ng mL−1 for pioglitazone, repaglinide, and nateglinide, respectively. The presented method was fully validated and can be used for the therapeutic monitoring of the targeted analytes in human plasma samples.

Ionic Liquid-Dispersive Micro-Extraction and Detection by High Performance Liquid Chromatography-Mass Spectrometry for Antifouling Biocides in Water.

A simple analytical method was developed and evaluated for the determination of two antifouling biocides using an ionic liquid-dispersive liquid-liquid micro-extraction (IL-DLLME) and a high-performance liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) analysis. Irgarol 1051 and Sea-Nine 211 were extracted from deionized water, lake water, and seawater using IL 1-hexyl-3-methylimidazolium hexafluorophosphate ([HMIm][PF6]) and ethyl acetate as the extraction solvent and the dispersion solvent. Several factors were considered, including the type and volume of extraction and dispersive solvent, IL amount, sample pH, salt effect, and cooling temperature. The developed method resulted in a recovery range of 78.7-90.3%, with a relative standard deviation (RSD, n = 3) less than 7.5%. The analytes were enriched greater than 40-fold, and the limits of detection (LOD) for two antifouling biocides were 0.01-0.1 μg L-1. The method was effectively applied for the analysis of real samples of freshwater as well as samples of seawater.

Characterization and Comparison of Steroidal Glycosides from Polygonatum Species by High-Performance Liquid Chromatography–Electrospray Ionization Mass Spectrometry

Polygonatum species have been used as traditional medicines and functional foods in Asia and Europe since ancient times. In this study, a fast and simple method based on liquid chromatography coupled with electrospray ionization mass spectrometry (LC-ESI-MS) was developed to systematically analyze and identify the steroidal glycosides in four major Polygonatum species distributed in Japan, including P. odoratum, P. falcatum, P. macranthum, and P. sibiricum. As a result, 31 steroidal glycosides were tentatively identified, including 18 known and 13 previously unreported glycosides. Their structures were identified by the interpretation of chromatographic behavior and ESI-MS fragmentation patterns. The identification of 31 steroidal glycosides was indicative of a common biogenetic pathway in Polygonatum species. Our study disclosed the chemical profiling of steroidal glycosides in the plants of Polygonatum species, which will benefit better phytochemotaxonomical and phytochemical understanding and quality control for their medicinal usage.