Ionization Tandem Mass Spectrometry Research Articles

Conversion of 5α-Androstane-3α,17β-diol to bis[(4-dimethylamino)phenyl carbamate] derivative for sensitive determination of its rat brain level by LC/ESI-MS/MS.

5α-Androstane-3α,17β-diol (3α,5α-Adiol) is a testosterone-derived neurosteroid and has anxiolytic and analgesic effects via γ-aminobutyric acid type A receptors as with the progesterone-derived neurosteroid, allopregnanolone (AP). Although the psychotropic drug-evoked changes in the brain AP concentration have been intensively studied, those in the brain 3α,5α-Adiol concentration remain poorly understood. One of the causes for this is the limited availability of a validated method for quantifying the brain 3α,5α-Adiol with a sufficient sensitivity and specificity, which is described in this study. To enhance the detectability of 3α,5α-Adiol by electrospray ionization-tandem mass spectrometry (ESI-MS/MS), derivatization with 4-dimethylaminobenzoyl azide was employed. The brain sample was purified by solid-phase extraction and the recovered 3α,5α-Adiol and the deuterated internal standard were derivatized, then measured by liquid chromatography (LC)/ESI-MS/MS with selected reaction monitoring. The derivatized 3α,5α-Adiol, i.e., the bis[(4-dimethylamino)phenyl carbamate] derivative, provided the intense doubly-protonated molecule as the precursor ion, then the specific product ion containing the 3α,5α-Adiol-skeleton by collision-induced dissociation. The detectability of 3α,5α-Adiol was eventually increased 1000-fold by derivatization. Separation of the derivatized 3α,5α-Adiol from its stereoisomers and interfering brain components was achieved using a SunShell Biphenyl column with an isopropyl alcohol-containing mobile phase. A good linearity in the sufficient concentration range, acceptable precision and accuracy, and negligible matrix effect were demonstrated by the validation tests. The animal (rat) study using this method revealed that the brain 3α,5α-Adiol levels were unaffected by the administration of fluoxetine (FLX) and clozapine (CLZ), in contrast to the significant increase of the AP levels. An LC/ESI-MS/MS method capable of quantifying 3α,5α-Adiol in the rat brain using a 20-mg tissue was developed and validated. The brain levels of 3α,5α-Adiol had an entirely different behavior from those of AP due to FLX and CLZ administration.

Polyphenol composition and antioxidant activity of fermentation combined with enzymatic hydrolysis modified Astragalus membranaceus stems

Astragalus membranaceus (AM) roots are a well-known homologous medicine and food in China. AM stems, which are discarded and not used effectively, also contain many active compounds and exhibit beneficial effects. It has the potential to be explored as antibiotic alternative. Fermentation combined with enzymatic hydrolysis (FEH) is an effective strategy for extracting polyphenol and improving the usage of AM stems. Therefore, in this study, the conditions of FEH and extraction for polyphenol in AM stems were screened. The antioxidant activity of extract from AM stems without and with FEH (AMSE and FAMSE) was evaluated. The metabolite profiles of phenolic acids and flavonoids in AMSE and FAMSE were characterized by ultra-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC–ESI-MS/MS). The results showed that the highest polyphenol content from AM stems was obtained with cellulase and pectinase (1:1, 2000 U/g), moisture content 43%, fermentation temperature 30 °C, and fermentation time 7 days. Selected extraction conditions of polyphenol were ethanol concentration 50%, ultrasonic power 500 W, extraction temperature 35 °C, and extraction time 40 min. On this condition, compared with AMSE, the polyphenol and flavonoid contents in FAMSE were significantly higher. FAMSE exhibited stronger DPPH, hydroxyl radical scavenging rate and reducing power than AMSE. The relative content of 3-(4-hydroxyphenyl)-propionic acid, dihydroferulic acid, isoferulic acid, 4-hydroxybenzoic acid, 4-hydroxyphenyllactic acid, ferulic acid, vanillic acid, syringic acid, gentisic acid, sinapic acid, apigenin, tricin, acacetin, daidzein, genistein, formononetin, prunetin, pratensein, rhamnocitrin and galangin were significantly upregulated in FAMSE.Graphical

Rapid bromate determination using short-column ion chromatography-mass spectrometry: Application to bromate quantification during ozonation

A streamlined, precise, and dependable method for the concurrent quantification of bromate has been established, employing ion chromatography in conjunction with electrospray ionization tandem mass spectrometry (IC-ESI-MS/MS). In an effort to expedite sample analysis duration, the AG18 short column was utilized for rapid separation of the specified analytes. Utilizing a blend of water and acetonitrile as the mobile phase within an optimized gradient elution setting, it was possible to achieve satisfactory resolution in under 3 minutes. Specifically, the mixing of acetonitrile in water samples improves the sensitivity and immunity of the method. This phenomenon may be attributed to the similar proportions of acetonitrile in the sample and the mobile phase, which effectively reduces the viscosity and surface tension of the droplets during the ESI process. Detection limits and quantification thresholds were 0.14 µg/L and 0.41 µg/L, respectively. Analyte recoveries, when spiked into tap water between 2.5 µg/L to 50 µg/L, ranged from 69.5 % to 116.7 %; precision metrics, measured as intra- and inter-day relative standard deviations, spanned 5.1–7.9 %. The devised approach encountered minimal interference from prevalent water matrix constituents, including chloride (50–200 mg/L), sulfate (25–200 mg/L), bicarbonate/carbonate (1–6 mM), and natural organic matter (1–8 mg/L). In environmental contexts, this methodology effectively tracked the production of bromate in controlled ozonation experiments conducted in the laboratory. Segmented ozone dosing reduced bromate production when the solution contained low concentrations of DOC, which provides an alternative strategy for controlling bromate production.

Selenium speciation analysis of selenium-enriched Shiitake mushrooms (Lentinula edodes) by HPLC-ESI-MS

Selenium (Se) is an essential component of critical enzymes and is intricately linked to human health. Shiitake mushrooms (Lentinula edodes) are considered as good dietary supplements for producing Se-enriched foods due to their high protein content and ability to absorb minerals from growth substrates. In this study, the distribution of soluble Se in Se-enriched L. edodes was analyzed by microwave digestion and hydride generation-atomic fluorescence spectrometry (HG-AFS). In order to evaluate the absorption and conversion effect of Se by L. edodes, the Se-containing compounds in selenized L. edodes were quantitatively and qualitatively analyzed by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS). It can be shown that L. edodes possessed a good biological transformation ability of organic Se enrichment though the quantitative analysis of three seleno-amino acids, selenocystine (Se-Cys2), methylselenocysteine (Se-MeSeCys) and selenomethionine (Se-Met), in selenized L. edodes. The structures of three unknown Se-containing compounds were identified by qualitative analysis, the results indicated that the possible structures were selenomethylmethionine (C6H14NO2Se), N-Acetyl-selenomethionine (C7H13NO3Se) and Se-methyl-5-selenoadenosinese-oxide (C12H18N5O3Se). The discovery of these Se compounds filled the research gap and provided a theoretical basis for molecular structure identification and mechanism study of organic Se in Se-enriched L. edodes.

Overweight/bowel dysmotility crosslinking and analogous laxative actions of two edible wild fruits in obese/constipated rats.

The prompt development of obesity/constipation is the most serious problem for both children and adults. Limited studies suggested an association between them but lacked preclinical studies. This study allows to evaluate their crosslink and to compare the aqueous extracts laxative actions of two edible wild fruits of Arbutus unedo (AUAE) and Crataegus monogyna (CMAE) in constipated high-fat diet (HFD) rats. Wistar rats were divided into experimental groups for 13 weeks: standard (SD) and HFD groups. SD-rats were randomly redivided into 2 groups: SD and SD + Loperamide (LOP, 3 mg/kg, b.w.). HFD-rats were randomly reseparated into HFD-group, (HFD + LOP)-group, [HFD + Yohimbine (YOH, 2 mg/kg, b.w.)]-group, [HFD+ LOP]-groups+ various doses of AUAE or CMAE (75, 150, and 300 mg/kg, b.w.). Diversified indicators were investigated to achieve the expected objectives, including; fecal parameters, gastrointestinal transit (GIT), gastric emptying (GE), oxidative stress-(OxS), blood biochemical analysis, and accompanied small/large bowel histological modification. The liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS) analysis of AUAE and CMAE allowed the identification of 11 and 6 phenolic compounds, respectively. In HFD-rats, the subsequent dysregulation of GI motility was markedly aggravated. More importantly, with the same way (CMAE and AUAE)-treated groups showed alleviated outcomes for the following: most stool parameters, GIT, and GE were remarkably recovered; a similar recovery pattern was observed in the histopathological structure, OxS, and blood biochemical indicators. Our results experimentally confirmed the crosslink between overweight and constipation and both fruits have potential as functional foods to reduce metabolic risk of the obesity associated with bowel dysmotility.

Comprehensive Secondary Metabolite Profiling and Antioxidant Activity of Aqueous and Ethanol Extracts of Neolamarckia cadamba (Roxb.) Bosser Fruits.

Neolamarckia cadamba (Rubiaceae) is a well-recognized medicinal plant with recorded therapeutical attributes. However, a thorough assessment of active compounds in its fruits is lacking, limiting their use and valorization in pharmacological industries. Thus, this study investigated variations in the fruits' secondary metabolite (SM) profiles, as well as antioxidant activities in aqueous (WA) and ethanol (ET) extracts. Liquid chromatography-electrospray ionization tandem mass spectrometry identified 541 SMs, of which 14 and 1 (di-O-glucosylquinic acid) were specifically detected in ET and WA, respectively. Phenolic acids (36.97%), flavonoids (28.10%), terpenoids (12.20%), and alkaloids (9.98%) were the dominant SMs. The SM profiles of the fruits in WA and ET were quite different. We revealed 198 differentially extracted (DE) metabolites between WA and ET, including 62 flavonoids, 57 phenolic acids, 45 terpenoids, 14 alkaloids, etc. Most DE flavones (36 out of 40), terpenoids (45 out of 45), and alkaloids (12 out of 14) had higher content in ET. Catechin and its derivatives, procyanidins, and tannins had higher content in WA. ABTS and DPPH assays showed that the antioxidant activity of ET was significantly higher than that of WA. Our findings will facilitate the efficient extraction and evaluation of specific active compounds in N. cadamba.

Multiple oxidative modifications on hemoglobin are elevated in breast cancer patients as measured by nanoflow liquid chromatography-tandem mass spectrometry

Breast cancer is strongly connected with elevated oxidative stress. Oxidative modifications of hemoglobin can serve as biomarkers for monitoring oxidative stress status in vivo. The structure of hemoglobin modifications derived from malondialdehyde (MDA) in human blood hemoglobin exists as N-propenal and dihydropyridine (DHP). This study reports the simultaneous quantification of eleven modified peptides in hemoglobin derived from MDA and advanced histidine oxidation in 16 breast cancer patients and 16 healthy women using nanoflow liquid chromatography nanoelectrospray ionization tandem mass spectrometry. The results reveal statistically significant increases in the formation of MDA-derived N-propenal and DHP of lysine and advanced oxidation of histidine in hemoglobin of breast cancer patients with the Mann-Whitney U-test p values < 0.0001 and the AUC of ROC between 0.9277 and 1.0. Furthermore, the elevation in modified peptides is significant in patients with early stages of breast cancer. By measuring these oxidative modifications in hemoglobin from a drop of blood, the role of lipid peroxidation and oxidative stress in breast cancer can be assessed using this sensitive assay.

Structural characterization and prebiotic activity of oligo-galacturonic acids from Osmunda japonica Thunb

An oligosaccharide, WOJP-AOS-b, with a molecular size of 1.8 kDa, was obtained through enzymatic hydrolysis of Osmunda japonica Thunb polysaccharides (WOJP-A). The structural characteristics of WOJP-AOS-b were elucidated using Fourier transform-infrared spectroscopy (FT-IR), Ultraviolet (UV) spectroscopy, Nuclear magnetic resonance (NMR) spectroscopy, and Eelectrospray ionization tandem mass spectrometry (ESI-MS/MS). Structural analysis revealed that galacturonic acid (GalpA) was the predominant monosaccharide component of WOJP-AOS-b, accounting for 90.91% of the total composition. FT-IR and NMR analyses confirmed that WOJP-AOS-b possesses a linear structure comprised of α-1,4-linked GalpA residues. MS/MS results indicated that WOJP-AOS-b consists of α-1,4-linked oligo-galacturonic acids with degrees of polymerization ranging from 2 to 6 (DP 2–6). Moreover, in vitro probiotic activity assays demonstrated that WOJP-AOS-b exerted beneficial effects on intestinal microbiota, particularly Bifidobacterium adolescentis ATCC 15703 and Bifidobacterium breve 689b. WOJP-AOS-b enhanced the optical density, short-chain fatty acid (SCFA) content, and lactic acid content in the culture medium. Furthermore, 16S rRNA analysis suggested that WOJP-AOS-b exhibits potential for treating obesity and inhibiting pathogenic bacteria, indicating its promising applications as a prebiotic.

Unusual polyunsaturated fatty acids in edible marine worms identified by covalent adduct chemical ionization mass spectrometry

Non-traditional seafood, such as spoon worms (Urechis unicinctus) and peanut worms (Sipunculus nudus), serves as both delicacies and potential solutions to the global food insecurity crisis. Despite being consumed primarily in parts of China, Korea, and Japan, the nutritional values especially the complex fatty acid compositions of these marine worms are difficult to characterize. To overcome this obstacle, we employed covalent adduct chemical ionization (CACI) tandem mass spectrometry for the de novo identification of their unusual polyunsaturated fatty acids (PUFA). Through this method, we identified several PUFA with polymethylene-interrupted (PMI) double bond configurations, including 22:3(7Z,13Z,16Z), a novel PUFA derived from sciadonic acid. U. unicinctus exhibits an exceptionally low n-6/n-3 PUFA ratio of 0.15, making it a potential functional food to counterbalance the n-6/n-3 imbalance in modern diets. S. nudus boasts notably high concentrations (∼3 %, wt/wt) of branched chain fatty acids (BCFA), exceeding typical levels found in dairy products.

Rapid detection of ingested acetaminophen on face mask by ambient ionization tandem mass spectrometry

BackgroundA regular face mask is comprised of three layers for resisting moisture, filtration, and absorbing oral fluid, respectively. Since the polymers with different polarities are used to make the layers, a face mask can be used as a sampling tool to retain polar or non-polar chemical and biochemical substances in the exhaled breath. In this study, thermal desorption-electrospray ionization tandem mass spectrometry (TD-ESI/MS/MS), an ambient ionization mass spectrometric technique, was used to detect trace acetaminophen that were exhaled and retained on the surface of different layers in a face mask. ResultsWith probe sampling combined with TD-ESI/MS/MS, the acetaminophen ion signal can be detected at the mouth/nostril region of the face mask after taking the acetaminophen tablet. The experimental results were similar to previous studies for the detection of acetaminophen in blood over time using LC/MS/MS. In addition, the intensities of acetaminophen on different layers of the face mask could reveal the differing distributions of exhaled acetaminophen on each layer. To explore the distribution of acetaminophen on the face mask surface, multiple probes were used to collect samples from different locations of the face mask for analysis. The molecular mapping of acetaminophen on the face mask was rendered by scaling the analyte ion signal intensity based on a temperature color gradient. The cartography showed a higher acetaminophen ion signal distribution on the mouth and nostril regions than in other areas of the face mask. SignificanceOwing to the advantages of a simple, sensitive, and non-invasive sampling approach, drug monitoring could be potentially performed to provide useful information for anti-drug of precision medicine in the future.

In-Depth Mass Spectrometry Study of Vanadium(IV) Complexes with Model Peptides.

Investigating the speciation of vanadium complexes in the presence of potential biomolecular targets under physiological conditions remains challenging, and further experimental techniques are needed to better understand the mechanism of action of potential metallodrugs. The interaction of two model peptides (angiotensin I and angiotensin II) with three well-known oxidovanadium(IV) compounds with antidiabetic and/or anticancer activity, [VIVO(pic)2(H2O)], [VIVO(ma)2], and [VIVO(dhp)2] (where pic, ma, and dhp are picolinate, maltolate, and 1,2-dimethyl-3-hydroxy-4(1H)-pyridinonate anions, respectively), was investigated by ESI-MS/MS (electrospray ionization tandem mass spectrometry) and complemented by EPR (electron paramagnetic resonance) spectroscopy measurements and theoretical calculations at the DFT (density functional theory) level. The results demonstrated that vanadium-peptide bonds are preserved after HCD (higher energy collisional dissociation) fragmentation, allowing for the identification of binding sites through a detailed analysis of the fragmentation spectra. Angiotensin I (AT1) and angiotensin II (AT2) exhibited different coordination behaviors. AT1, with two His residues (His6, His9), prefers to form [AT1 + VOL] adducts with both histidine residues coordinated to the metal ion, while AT2, which has only His6, can bind the metal in a monodentate fashion, forming also [AT2 + VOL2] adducts. Insights from this study pave the way to ESI-MS/MS investigations of more complex systems, including target proteins and further development of vanadium-based drugs.

SIL-IS LC-ESI-MS/MS method for simultaneous quick detection of amoxicillin and clavulanic acid in human plasma: Development, validation and its application to a pharmacokinetics study.

A liquid chromatography electrospray ionization tandem mass spectrometry method with amoxicillin-d4 as the stable isotope-labeled internal standard for simultaneous quick detection of amoxicillin and clavulanic acid in human plasma was developed and validated. Chromatographic separations were performed on a Hedera ODS-2 column (2.1 × 150 mm, 5μm). The mobile phases for gradient elution were aqueous solution containing 0.2% acetic acid (AA) (mobile phase A) together with organic phase solution (acetonitrile and methanol mixed solution, mobile phase B). Mass spectrometry was performed using negative electrospray ionization in multiple reaction monitoring mode. The target fragment ion pairs of amoxicillin, clavulanic acid and amoxicillin-d4 were m/z 364.1 → 223.1, 198.1 → 135.9 and 368.1 → 227.1, respectively. The linear ranges of this method were 40-5,000 ng/ml for amoxicillin and 30-2,500 ng/ml for clavulanic acid, with coefficient of determination > 0.9900. This method validation included selectivity, standard curve, lower limit of quantitation, accuracy, precision, recovery, matrix effect (hemolytic matrix and hyperlipidemic matrix), carryover, stability, dilution reliability and incurred sample reanalysis study. A successful application of this method was realized in a pharmacokinetic study after administration of amoxicillin-clavulanic acid potassium granules.

Determination of azodicarbonamide in flour samples using high-performance liquid chromatography–tandem mass spectrometry with xanthydrol pre-column derivatisation

Azodicarbonamide (ADA) is approved as a food additive in flour products due to its oxidising and bleaching properties. However, it is prohibited in Australia and Europe on account of its toxicity and the risk of causing asthma in humans. A method was developed to determine ADA in actual flour samples. This work presents an optimised methodology based on derivatisation and clean-up procedures followed by ultra-performance liquid chromatography coupled with electrospray ionisation tandem mass spectrometry (UPLC–ESI-MS/MS). The analytical method was successfully validated. An excellent result was obtained for the linearity of matrix-matched calibration curves (R 2 > 0.99) in the concentration range of 0.10–80 mg/kg. The recovery rate varied from 81.7% to 102.3%. The relative standard deviations (RSDs) of repeatability (n = 6) were 1.3–4.1%, and inter-day RSDs (n = 6) were 2.2–4.8%. The limit of detection and the limit of quantification were 0.014 and 0.042 mg/kg, which were significantly lower than the requirement of 45 mg/kg stipulated in the Chinese National Food Safety Standard (GB 2760-2014). The detection rate of ADA in 26 flour samples was 23.1%, with the concentration ranging from 0.023 to 23.2 mg/kg.

Pharmacokinetic study of iptacopan and its two acyl glucuronide metabolites in monkey plasma by liquid chromatography combined with electrospray ionization tandem mass spectrometry.

In this study, a simple and sensitive liquid chromatography tandem mass spectrometric method was developed and validated for the determination of iptacopan and two acyl glucuronidation metabolites in monkey plasma. The plasma sample was precipitated with acetonitrile and then separated on an Acquity UPLC BEH C18 column (2.1 × 100 mm, 1.7 μm) using 0.1% formic acid and 5 mM ammonium acetate in water and acetonitrile as the mobile phase. The mass spectrometry (MS) detection was performed in positive multiple reactions monitoring (MRM) mode with precursor-to-production transitions. The developed assay was validated over the range of 1-2000 ng/mL for three analytes with correlation coefficient (r) more than 0.99. The validation parameters including accuracy, precision, carryover effect, matrix effect, recovery, and stability were all within the acceptable limits. The validated method has been applied to investigate the pharmacokinetics of iptacopan and its two acyl glucuronidation metabolites in monkey plasma. After intravenous administration, iptacopan showed low clearance (2.75 mL/min/kg) in monkey plasma. After oral administration, the bioavailability was 55.43%. The exposure (AUC0-t) of direct acyl glucuronide (AG) of iptacopan accounts for 9.73% of the iptacopan plasma exposure. The AUC0-t of AG of dealkylated metabolite of iptacopan was present at a lower level, accounting for 0.5% of the iptacopan plasma exposure.

A Flavonoid Concentrate from Moringa Oleifera Lam. Leaves Extends Exhaustive Swimming Time by Improving Energy Metabolism and Antioxidant Capacity in Mice.

Moringa oleifera Lam. leaves contain various nutrients and bioactive compounds. The present study aimed to assess the anti-fatigue capacity of a flavonoids concentrate purified from M. oleifera Lam. leaves. The total flavonoids in the purified extract were analyzed by ultra-performance liquid chromatography electrospray ionization tandem mass spectrometry (UPLC-MS/MS). The mice were supplemented with purified M. oleifera Lam. leaf flavonoid-rich extract (MLFE) for 14 days. The weight-loaded forced swimming test was used for evaluating exercise endurance. The 90-min non-weight-bearing swimming test was carried out to assess biochemical biomarkers correlated to fatigue and energy metabolism. UPLC-MS/MS analysis identified 83 flavonoids from MLFE. MLFE significantly increased the swimming time by 60%. Serum lactate (9.9 ± 0.9 vs. 8.9 ± 0.7), blood urea nitrogen (BUN) (8.8 ± 0.8 vs. 7.2 ± 0.5), and nonesterified fatty acid (NEFA) (2.4 ± 0.2 vs. 1.7 ± 0.3) were significantly elevated; phosphoenolpyruvate carboxykinase (PEPCK), glucokinase (GCK), and nuclear factor erythroid 2-related factor 2 (Nrf2) mRNA expression were significantly downregulated; and heme oxygenase 1 mRNA expression was significantly upregulated in muscle after swimming. MLFE supplement significantly decreased serum lactate (8.0 ± 1.0 vs. 9.9 ± 0.9), BUN (8.6 ± 0.4 vs. 8.9 ± 0.8), and NEFA (2.3 ± 0.4 vs. 2.4 ± 0.2) and increased the protein and mRNA expression of GCK, PEPCK, and Nrf2. The enhancement of glucose metabolism and antioxidant function by MLFE contributes partly to its anti-fatigue action.

A validated LC-MS/MS method for the simultaneous quantification of iothalamate and hippuran in serum and urine for non-radioactive kidney function assessment

A novel liquid chromatography-tandem mass spectrometry method is described for the quantitative determination of the kidney function markers iothalamate and hippuran in human serum and urine. It is based on protein precipitation with methanol followed by dilution of the supernatant for serum and simple dilution for urine. The polar analytes are chromatographically separated by a 6.5-min gradient on a low-ligand density reversed-phase column; detection is performed by electrospray ionization tandem mass spectrometry in the positive ion mode against stable-isotope labeled internal standards.The results of a thorough method validation show that iothalamate and hippuran can be simultaneously quantified in the concentration ranges 0.500 – 30.0 ng/mL and 10.0 – 5000 ng/mL for serum and urine, respectively, with values for CV and absolute bias not exceeding 10 %, and with sufficient stability in all relevant matrices and solvents. The method was successfully applied for the analysis of serum and urine samples of multiple individuals who received both iothalamate and hippuran.

Cistus libanotis from Algeria: Phytochemical analysis by GC/MS, HS-SPME-GC/MS, LC–MS/MS and its anticancer activity

In this paper, Cistus libanotis (Cistus clusii Dunal) from Algeria was investigated. This plant is utilized in numerous industries, mostly in perfumery and, more recently, as a raw material for dietary supplements. For the first time, the present study evaluated the anticancer potential of Algerian C. libanotis by performing a comprehensive phytochemical investigation. The volatile fraction of the fresh plant material of C. libanotis was investigated using headspace solid-phase microextraction (HS-SPME) coupled to GC-MS, and the chemical composition of the essential oil (EO) of C. libanotis was examined using GC-MS technique; additionally, the phenolic compounds were identified and quantified using liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). A healthy cell line (L929) and two cancer cell lines (CAPAN-1 and dld-1) were used to test the ethanolic extract's cytotoxicity. HS-SPME-GC/MS analysis identified sabinene (25.3 %) and α-thujene (23.8 %) as principal components. In EO the major ingredients were γ-terpinene (17.4 %), camphene (16.13 %), α-phellandrene (15.36 %), and 4-carene (13.54 %). Nevertheless, 24 components were identified by LC-ESI-MS/MS analysis and shikimic acid, luteolin and hesperidin were most abundant. Further, the ethanolic extract of C. libanotis showed a significant cytotoxic effect against dld-1 and CAPAN-1 cell lines, while it was less active against the healthy cell line L929.

Quantitative analysis of phenolics in Trifolium pratense L. flowers and evaluation of antioxidant activity by sensory

Trifolium pratense L. flowers (TPF) were collected and dried in shade in this study. After extraction in methanol, a diluted solution was applied to the liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) device to determine the bioactive compounds quantitatively. Isoquercitrin (38.64 mg/g extract), coumarin (13.66 mg/g extract), and catechin (12.52 mg/g extract) were verified as major products. Antioxidant activity of TPF was performed using a potentiometric PVC membrane sensor to evaluate 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and total phenolic content of TPF. TPF inhibited the DPPH radical as 31.4 ± 0.02% at the 500-ppm concentration. However, the DPPH activity of gallic acid was determined as 81.43 ± 0.07% and 92.44 ± 0.1% at the TPF concentrations of 12.5 ppm and 25 ppm, respectively. In addition, the total phenolic content was calculated to be 82.4 ± 0.15 mg gallic acid eq/g extract. It was observed that TPF has the potential to be an antioxidant and a valuable source of isoquercitrin, coumarin, and catechin.

Skin derived branched‐chain fatty acids in fetal horse gut

AbstractBranched‐chain fatty acids (BCFAs) are mostly saturated fatty acids with a methyl branch at the penultimate or antepenultimate position to the CH3 end. Very‐long‐chain BCFAs (C ≥ 20) are uniquely found in surface lipids. Human and California sea lion (Zalophus californianus) are the only two species that possess vernix at birth, and vernix particles carry loads of BCFA to the gut, potentially influencing the establishment of the first microbiota. Horse (Equus caballus) contains high levels of BCFA in its surface lipids, and the current study aims to investigate if BCFA are components of a neonatal foal's gut. Electron ionization tandem mass spectrometry was used to distinguish iso‐ and anteiso‐form of BCFA from straight‐chain fatty acids. Abundant very‐long‐chain iso‐BCFA, mainly even‐numbered iso‐20:0, iso‐22:0, iso‐24:0, and iso‐26:0 were found in horse meconium but not in their manure collected a few months later. There are little differences in BCFA types and concentrations between foal manure and adult manure. Moderate to high levels of very‐long‐chain anteiso‐BCFA were also found. Comparisons of horse meconium BCFA to horse skin cholesterol ester BCFA content and to meconium from human and sea lion suggest its skin derived origin. The study expands our knowledge on the gut nutritional environment of a newborn horse, and further study is needed to establish the relationship between gut BCFA and microbiota composition in the first few hours of life.Practical Applications: Branched‐chain fatty acids (BCFA) are bioactive compounds found in vernix caseosa, the lipid‐laden material covering the surface of a newborn baby. BCFA also reaches high concentrations from the third trimester of gestation until birth. However, the exact functionality and mechanisms of BCFA in the surface and gut of a fetus remain unclear. The current study aims to clarify the lipid conditions in the gut of newborn foals and to identify the associations between BCFA in the gut and on the skin at a critical point when the horse's microbiota establishes itself. The findings of the current study lay a path for studying the physiological functions of BCFA in horse models, potentially accelerating research related to BCFA.

Application of marine sponges for biomonitoring active pharmaceutical ingredients (APIs) in coral reefs. Optimization of an SPME and ESI-LC-MS/MS method

Chemical pollution is a threat to coral reefs. To preserve them, it is crucial to monitor novel contaminants and assess the related risks. The occurrence of active pharmaceutical ingredients (APIs) in coral reefs has been poorly investigated until now. Under this light, we tested the use of the marine sponge Cf. Hyrtios as bio-monitors and conducted a pilot study in the Faafu Atoll (Maldives). Analyses were carried out by in vivo solid-phase microextraction (SPME) and liquid chromatography (LC) electrospray ionization (ESI) tandem mass spectrometry (MS/MS). Twelve APIs were selected for method optimization. Limits of quantitation (LOQs) were in the 0.6 and 2.5 ng/g range, accuracy between 86.5 % and 104.7 %, and precision between 3.0 % and 14.9 %. All the sponges located in the inner reefs resulted contaminated with at least one API. Gabapentin and Carbamazepine displayed the highest detection rates, while Ketoprofen had the highest concentration (up to 15.7 ng/g).