Displaying publications 1 - 20 of 322 in total

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  1. Foodomics Reveals Anti-Obesity Properties of Cannabinoids from Hemp Oil
    Ding Z, Jiang F, Shi J, Wang Y, He M, Tan CP, et al.
    Mol Nutr Food Res, 2023 Jan;67(2):e2200508.
    PMID: 36382382 DOI: 10.1002/mnfr.202200508
    SCOPE: Molecular networking (MN) analysis intends to provide chemical insight of untargeted mass spectrometry (MS) data to the user's underlying biological questions. Foodomics is the study of chemical compounds in food using advanced omics methods. In this study, an MS-MN-based foodomics approach is developed to investigate the composition and anti-obesity activity of cannabinoids in hemp oil.

    METHODS AND RESULTS: A total of 16 cannabinoids are determined in optimized microwave pretreatment of hemp oil using the developed approach. Untargeted metabolomics analysis reveals that cannabinoid extract (CE) and its major constituent (cannabidiol, CBD), can alleviate high glucose-induced increases in lipids and carbohydrates, and decreases in amino acid and nucleic acid. Moreover, CE and CBD are also found to suppress the expression levels of mdt-15, sbp-1, fat-5, fat-6, fat-7, daf-2, and elevate the expression level of daf-1, daf-7, daf-16, sod-3, gst-4, lipl-4, resulting in the decrease of lipid synthesis and the enhance of kinetism. Canonical correspondence analysis (CCA) uncovers strong associations between specific metabolic alterations and gene expression levels.

    CONCLUSION: These findings from this exploratory study offer a new insight into the roles of cannabinoids in the treatment of obesity and related complications.

    Matched MeSH terms: Tandem Mass Spectrometry/methods
  2. Electrokinetic Extraction of Doxorubicin from Biological Fluids by Polymer Inclusion Membrane Sampling Probe
    Tey HY, Breadmore MC, See HH
    Anal Chem, 2023 Jan 31;95(4):2134-2139.
    PMID: 36649064 DOI: 10.1021/acs.analchem.2c02937
    A polymer inclusion membrane (PIM) based sampling probe was developed for electrokinetic extraction of drugs from biological fluids. The probe was fabricated by dip-coating a nonconductive glass capillary tube in a homogeneous PIM solution for three cycles. The PIM solution comprised cellulose triacetate (CTA), 2-nitrophenyl octyl ether (NPOE), and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [EMIM][NTf2] in a ratio of 5:4:2. The developed probe electrokinetically extracted doxorubicin from human plasma, human serum, and dried blood spot (DBS). The practicability and reliability of the electrokinetic extraction were evaluated by LC-MS/MS to quantify the desorption of extracted doxorubicin. Under the optimized conditions, a quantification limit of 0.2-2 ng/mL was achieved for the three biological samples. The probe was further integrated into a portable battery-powered device for safe low-voltage (36 V) electrokinetic extraction. The developed technique is envisioned to provide a more efficient analytical workflow in the laboratory.
    Matched MeSH terms: Tandem Mass Spectrometry*
  3. Effects of high-voltage electrostatic field (HVEF) on frozen shrimp (Solenocera melantho) based on UPLC-MS untargeted metabolism
    Liu J, Zhu F, Yang J, Wang Y, Ma X, Lou Y, et al.
    Food Chem, 2023 Jun 15;411:135499.
    PMID: 36696717 DOI: 10.1016/j.foodchem.2023.135499
    Shrimp meat is prone to autolysis and decay due to the abundance of endogenous enzymes and contamination from microorganisms. HVEF freezing can slow the spoilage of shrimp, producing small and uniform ice crystals, resulting in less damage to muscle tissue. In this study, HVEF technique was used to freeze the shrimp (Solenocera melantho), and the UPLC-MS metabolic technique was used to investigate the metabolites of frozen shrimp meat. Compared with the control group, 367 differential metabolites were identified in the HVEF group. Mapping them to the KEGG database, there were 108 with KEGG ID. Purine metabolism and pyrimidine metabolism were the most enriched pathways. In addition, phosphatidylcholines (PCs), inosine (HxR), and l-valine were identified as potential biomarkers associated with lipid, nucleotide, and organic acid metabolism, respectively. Overall, HVEF can improve freezing quality of shrimp meat by slowing down the metabolism of substances in the muscle of S. melantho.
    Matched MeSH terms: Tandem Mass Spectrometry*
  4. Fulltext Pathogenicity of monokaryotic and dikaryotic mycelia of Ganoderma boninense revealed via LC-MS-based metabolomics
    Santiago KAA, Wong WC, Goh YK, Tey SH, Ting ASY
    Sci Rep, 2024 Mar 04;14(1):5330.
    PMID: 38438519 DOI: 10.1038/s41598-024-56129-8
    This study compared the pathogenicity of monokaryotic (monokaryon) and dikaryotic (dikaryon) mycelia of the oil palm pathogen Ganoderma boninense via metabolomics approach. Ethyl acetate crude extracts of monokaryon and dikaryon were analysed by liquid chromatography quadrupole/time-of-flight-mass spectrometry (LC-Q/TOF-MS) coupled with multivariate data analysis using MetaboAnalyst. The mummichog algorithm was also used to identify the functional activities of monokaryon and dikaryon without a priori identification of all their secondary metabolites. Results revealed that monokaryon produced lesser fungal metabolites than dikaryon, suggesting that monokaryon had a lower possibility of inducing plant infection. These findings were further supported by the identified functional activities. Monokaryon exhibits tyrosine, phenylalanine, and tryptophan metabolism, which are important for fungal growth and development and to produce toxin precursors. In contrast, dikaryon exhibits the metabolism of cysteine and methionine, arginine and proline, and phenylalanine, which are important for fungal growth, development, virulence, and pathogenicity. As such, monokaryon is rendered non-pathogenic as it produces growth metabolites and toxin precursors, whereas dikaryon is pathogenic as it produces metabolites that are involved in fungal growth and pathogenicity. The LC-MS-based metabolomics approach contributes significantly to our understanding of the pathogenesis of Ganoderma boninense, which is essential for disease management in oil palm plantations.
    Matched MeSH terms: Tandem Mass Spectrometry*
  5. LC-MS-MS method for mitragynine and 7-hydroxymitragynine in hair and its application in authentic hair samples of suspected kratom abusers
    Rhee J, Shin I, Kim J, Lee J, Cho B, Kim J, et al.
    J Anal Toxicol, 2024 Jul 13;48(6):429-438.
    PMID: 38780234 DOI: 10.1093/jat/bkae041
    Kratom is a natural psychoactive product known primarily in Southeast Asia, including Thailand, Malaysia, etc. It is also known as krathom, kakuam, ithang, thom (Thailand), biak-biak, ketum (Malaysia) and mambog (Philippines) and is sometimes used as an opium substitute. It is stimulant at doses of 1-5 g, analgesic at doses of 5-15 g and euphoric and sedative at doses of >15 g. Mitragynine is the most abundant indole compound in kratom (Mitragyna speciosa) and is metabolized in humans to 7-hydroxymitragynine, the more active metabolite. Adverse effects include seizures, nausea, vomiting, diarrhea, tachycardia, restlessness, tremors, hallucinations and death. There are few studies on the analytical method for the detection of mitragynine and 7-hydroxymitragynine in hair. Therefore, this study proposes a liquid chromatography-tandem mass spectrometry (LC-MS-MS) method for the analysis of kratom in hair. Hair samples were first weighed to ∼10 mg and washed with methanol. Then the washed hair samples were cut into pieces and incubated in methanol with stirring and heating (16 h/38℃). Extracts were then analyzed by LC-MS-MS. This method was validated by determining the limit of detection (LOD), limit of quantification, linearity, intra- and inter-day accuracy and precision, recovery and matrix effects. The intra- and inter-day precision (CV%) and accuracy (bias%) were within ±20%, which was considered acceptable. Using this newly developed LC-MS-MS method, the simultaneous detection of mitragynine and 7-hydroxymitragynine in six authentic hair samples was achieved to provide the direct evidence of kratom use in the past. Mitragynine concentrations ranged from 16.0 to 2,067 pg/mg (mean 905.3 pg/mg), and 7-hydroxymitragynine concentrations ranged from 0.34 to 15 pg/mg (mean 7.4 pg/mg) in six authentic hair samples from kratom abusers. This may be due to the higher sensitivity of the LOD in this study, with values of 0.05 pg/mg for mitragynine and 0.2 pg/mg for 7-hydroxymitragynine in hair.
    Matched MeSH terms: Tandem Mass Spectrometry*
  6. Proteomic analysis of Moroccan cobra Naja haje legionis venom using tandem mass spectrometry
    Malih I, Ahmad rusmili MR, Tee TY, Saile R, Ghalim N, Othman I
    J Proteomics, 2014 Jan 16;96:240-52.
    PMID: 24269350 DOI: 10.1016/j.jprot.2013.11.012
    The proteome of the venom of Naja haje legionis, the only medically important elapid species in Morocco, has been elucidated by using a combination of proteomic techniques that includes size exclusion chromatography, reverse-phase HPLC, Tricine/SDS-Page, tryptic digestion, Q-TOF tandem mass spectrometry and database search. The sequence analysis of venom fractions revealed a highly complex venom proteome which counts a total of 76 proteins identified from database that can be assigned into 9 proteins families. We report the identification of: cobra venom factor (CVF), l-amino-acid oxidases (LAAO), acetylcholinesterase (AChE), snake venom metalloproteinases (SVMP), cysteine rich secretory proteins (CRISP), venom nerve growth factor (vNGF), phospholipases A2 (PLA2), vespryns, kunitz-type inhibitor, short neurotoxins, long neurotoxins, weak neurotoxins, neurotoxin like proteins, muscarinic toxins, cardiotoxins and cytotoxins. Comparison of these proteins showed high sequence homology with proteins from other African and Asian cobras. Further works are needed to assess the contribution of individual toxins in venom toxicity.
    Matched MeSH terms: Tandem Mass Spectrometry*
  7. Taxonomy and toxicity of a bloom-forming Ostreopsis species (Dinophyceae, Gonyaulacales) in Tahiti island (South Pacific Ocean): one step further towards resolving the identity of O. siamensis
    Chomérat N, Bilien G, Viallon J, Hervé F, Réveillon D, Henry K, et al.
    Harmful Algae, 2020 09;98:101888.
    PMID: 33129466 DOI: 10.1016/j.hal.2020.101888
    Among dinoflagellates responsible for benthic harmful algal blooms, the genus Ostreopsis primarily described from tropical areas has been increasingly reported from subtropical and temperate areas worldwide. Several species of this toxigenic genus produce analogs of palytoxin, thus representing a major threat to human and environmental health. The taxonomy of several species needs to be clarified as it was based mostly on morphological descriptions leading in some cases to ambiguous interpretations and misidentifications. The present study aims at reporting a benthic bloom that occurred in April 2019 in Tahiti island, French Polynesia. A complete taxonomic investigation of the blooming Ostreopsis species was realized using light, epifluorescence and field emission electron microscopy and phylogenetic analyses inferred from LSU rDNA and ITS-5.8S rDNA regions. Toxicity of a natural sample and strains isolated from the bloom was assessed using both neuroblastoma cell-based assay and LC-MS/MS analyses. Morphological observations showed that cells were round to oval, large, 58.0-82.5 µm deep (dorso-ventral length) and 45.7-61.2 µm wide. The cingulum was conspicuously undulated, forming a 'V' in ventral view. Thecal plates possessed large pores in depressions, with a collar rim. Detailed observation also revealed the presence of small thecal pores invisible in LM. Phylogenetic analyses were congruent and all sequences clustered within the genotype Ostreopsis sp. 6, in a subclade closely related to sequences from the Gulf of Thailand and Malaysia. No toxicity was found on the field sample but all the strains isolated from the bloom were found to be cytotoxic and produced ostreocin D, a lower amount of ostreocins A and B and putatively other compounds. Phylogenetic data demonstrate the presence of this species in the Gulf of Thailand, at the type locality of O. siamensis, and morphological data are congruent with the original description and support this identification.
    Matched MeSH terms: Tandem Mass Spectrometry*
  8. Direct Analysis of Glyphosate, Glufosinate, and Their Metabolites in Palm Oil Using Liquid Chromatography with Tandem Mass Spectrometry
    Shinde R, Halim N, Banerjee AK
    J AOAC Int, 2020 Nov 01;103(6):1528-1533.
    PMID: 33247748 DOI: 10.1093/jaoacint/qsaa066
    BACKGROUND: Glyphosate and glufosinate are broad-spectrum herbicides which are frequently used in palm oil plantations for weed control. Metabolites of these herbicides are known to have environmental and food safety implications. As there is no validated method for multiresidue testing of these herbicides and their metabolites in palm oil products, a new method was needed for the purpose of regulatory analysis.

    OBJECTIVE: In this study, we endeavored to develop a rapid method for multiresidue analysis of glyphosate (+aminomethylphosphonic acid) and glufosinate (+3-methylphosphinicopropionic acid and N-acetyl-glufosinate) in refined and crude palm oil matrices using liquid chromatography (LC) tandem mass spectrometry (MS/MS).

    METHOD: The optimized sample preparation workflow included extraction of refined or crude palm oil (10 g) with acidified water (0.1 M HCl), cleanup by phase separation with dichloromethane, and analysis by LC-MS/MS with multiple reaction monitoring.

    RESULTS: The use of a Torus-DEA LC column ensured simultaneous analysis of these compounds within a runtime of 10 min. The LOQ of these analytes was 0.01 mg/kg, except that of aminomethylphosphonic acid which was 0.02 mg/kg. The method sensitivity complied with the national maximum residue limits of Malaysia and the European Union. Also, the method selectivity, sensitivity, accuracy, and precision were aligned with the SANTE/12682/2019 guidelines of analytical quality control.

    CONCLUSIONS: The potentiality of the optimized method lies in a high throughput direct analysis of glyphosate and glufosinate with their metabolites in a single chromatographic run. The method is fit for purpose for regulatory testing of these residues in a broad range of palm oil matrices.

    HIGHLIGHTS: The study reports for the first time a validated method for simultaneous analysis of glyphosate, glufosinate, and their metabolites in a range of palm oil products. The method did not require a derivatization step and provided a high throughput analysis of these compounds with satisfactory selectivity, sensitivity, accuracy, and precision.

    Matched MeSH terms: Tandem Mass Spectrometry*
  9. Bioequivalence of cefalexin in healthy Chinese subjects
    Lv X, Zhong G, Yao H, Wu J, Ye S
    Int J Clin Pharmacol Ther, 2021 Nov;59(11):725-733.
    PMID: 34448694 DOI: 10.5414/CP203986
    OBJECTIVE: An earlier three-way crossover study evaluating bioequivalence of 3 cefalexin formulations (capsule for reference, capsule and tablet for test) in healthy subjects in Malaysia showed that the intra-individual coefficients of variation were 9.25% for AUC0-t, 9.54% for AUC0-∞, and 13.90% for Cmax. It is preliminarily stated that cefalexin is not a high-variation product. The here-presented clinical study in China was carried out to analyze the pharmacokinetic properties of two preparations in fasting and postprandial condition to assess the bioequivalence of the test preparation and reference preparation when administered on a fasting and postprandial basis in healthy Chinese subjects and to observe the safety of the test preparation and reference preparation in healthy Chinese subjects.

    MATERIALS AND METHODS: In this trial, a total of 56 eligible subjects were randomly assigned to the fasting group and the postprandial group. The two groups were given 250 mg of the test and reference preparation, respectively. Liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was applied to determine the plasma concentration of cefalexin. PhoenixWinNonlin software (V7.0) was used to calculate the pharmacokinetic parameters of cefalexin using the non-compartmental model (NCA), and the bioequivalence and safety results were calculated by SAS (V9.4) software.

    RESULTS: The main pharmacokinetic parameters of the test and reference preparations were as follows, the fasting group: Cmax 12.59 ± 2.65 μg/mL, 12.72 ± 2.28 μg/mL; AUC0-8h 20.43 ± 3.47 h×μg/mL, 20.66 ± 3.38 h×μg/mL; AUC0-∞ 20.77 ± 3.53 h×μg/mL, 21.02 ± 3.45 h×μg/mL; the postprandial group: Cmax 5.25 ± 0.94 μg/mL, 5.23 ± 0.80 μg/mL; AUC0-10h 16.92 ± 2.03 h×μg/mL, 17.09 ± 2.31 h×μg/mL; AUC0-∞ 17.33 ± 2.09 h×μg/mL, 17.67 ± 2.45 h×μg/mL.

    CONCLUSION: The 90% confidence intervals of geometric mean ratios of test preparation and reference preparation were calculated, and the 90% confidence intervals of geometric mean ratios of Cmax, AUC0-10h, and AUC0-∞ were within the 80.00% ~ 125.00% range in both groups. Both Cmax and AUC met the pre-determined criteria for assuming bioequivalence. The test and reference products were bioequivalent after administration under fasting as well as under fed conditions in healthy Chinese subjects. This study may suggest that successful generic versions of cefalexin not only guarantee the market supply of such drugs but can also improve the safety and effectiveness and quality controllability of cefalexin through a new process and a new drug composition ratio.

    Matched MeSH terms: Tandem Mass Spectrometry*
  10. Development of dispersive inclusion complex microextraction for the analysis of nitrosamines in medicinal products
    Tay KSJ, Breadmore MC, Soh ES, See HH
    J Chromatogr A, 2022 Dec 06;1685:463605.
    PMID: 36375217 DOI: 10.1016/j.chroma.2022.463605
    A new dispersive inclusion complex microextraction (DICM) approach coupled with ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) for the determination of n-nitrosamine impurities in different medicinal products is demonstrated for the first time. The proposed DICM procedures consist of a dispersive liquid phase microextraction steps employing cyclodextrin as an inclusion complex agent to extract n-nitrosamines namely N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA), N-nitrosodiisopropylamine (NDIPA), N-ethyl-N-nitrosoisopropylamine (NEIPA) and N-nitroso-di-n-butylamine (NDBA) present in the medicinal products. The sample solutions were prepared by mixing 5% (m/v) NaCl solution with 1.5 mM β-cyclodextrin and 20 mM sodium dodecyl sulphate to form a stable inclusion complex and subsequently extracted into dichloromethane as an extraction solvent. The enriched solution was reconstituted into aqueous solution prior to UPLC-MS/MS analysis. The method showed good linearity in the range of 0.036-1 ng/mL with a correlation coefficient of at least 0.995, acceptable reproducibility (RSD 0.5-5.8%, n=5), low limits of detection (0.011-0.018 ng/mL), and satisfactory relative recoveries (96-105%). The results obtained were found to be at least 10-fold more sensitive comparable to those obtained using validated direct sample dissolutions coupled with UPLC-MS/MS approach.
    Matched MeSH terms: Tandem Mass Spectrometry/methods
  11. Assessment of 18 endocrine disrupting chemicals in tap water samples from Klang Valley, Malaysia
    Haron DEM, Yoneda M, Hod R, Ramli MR, Aziz MY
    Environ Sci Pollut Res Int, 2023 Nov;30(51):111062-111075.
    PMID: 37801249 DOI: 10.1007/s11356-023-30022-9
    Multiclass of endocrine disrupting chemicals (EDCs) such as nine perfluoroalkyl and polyfluoroalkyl substances (PFAS), five bisphenols, and four parabens were analysed in tap water samples from Malaysia's Klang Valley region. All samples were analysed using liquid chromatography mass tandem spectrometry (LC-MS/MS) with limit of quantitation (LOQ) ranged between 0.015 and 5 ng/mL. Fifteen of the 18 EDCs were tested positive in tap water samples, with total EDC concentrations ranging from 0.28 to 5516 ng/L for all 61 sampling point locations. In a specific area of the Klang Valley, the total concentration of EDCs was found to be highest in Hulu Langat, followed by Sepang, Putrajaya, Petaling, Kuala Lumpur, Seremban, and Gombak/Klang. PFAS and paraben were the most found EDCs in all tap water samples. Meanwhile, ethyl paraben (EtP) exhibited the highest detection rate, with 90.2% of all locations showing its presence. Over 60% of the regions showed the presence of perfluoro-n-butanoic acid (PFBA), perfluoro-n-hexanoic acid (PFHXA), perfluoro-n-octanoic acid (PFOA), perfluoro-n-nonanoic acid (PFNA), and perfluoro-1-octanesulfonate (PFOS), whereas the frequency of detection for other compounds was less than 40%. The spatial distribution and mean concentrations of EDCs in the Klang Valley regions revealed that Hulu Langat, Petaling Jaya, and Putrajaya exhibited higher levels of bisphenol A (BPA). On the other hand, Kuala Lumpur and Sepang displayed the highest mean concentrations of PFBA. In the worst scenario, the estimated daily intake (EDI) and risk quotient of some EDCs in this study exceeded the acceptable daily limits recommended by international standards, particularly for BPA, PFOA, PFOS, and PFNA, where the risk quotient (RQ) was found to be greater than 1, indicating a high risk to human health. The increasing presence of EDCs in tap water is undoubtedly a cause for concern as these substances can have adverse health consequences. This highlights the necessity for a standardised approach to evaluating EDC exposure and its direct impact on human populations' health.
    Matched MeSH terms: Tandem Mass Spectrometry/methods
  12. Identification and Quantification of Affinity-Purified Proteins with MaxQuant, Followed by the Discrimination of Nonspecific Interactions with the CRAPome Interface
    Lee PY, Low TY
    Methods Mol Biol, 2023;2690:299-310.
    PMID: 37450156 DOI: 10.1007/978-1-0716-3327-4_25
    Affinity purification coupled to mass spectrometry (AP-MS) is a powerful method to analyze protein-protein interactions (PPIs). The AP-MS approach provides an unbiased analysis of the entire protein complex and is useful to identify indirect interactors. However, reliable protein identification from the complex AP-MS experiments requires appropriate control of false identifications and rigorous statistical analysis. Another challenge that can arise from AP-MS analysis is to distinguish bona fide interacting proteins from the non-specifically bound endogenous proteins or the "background contaminants" that co-purified by the bait experiments. In this chapter, we will first describe the protocol for performing in-solution trypsinization for the samples from the AP experiment followed by LC-MS/MS analysis. We will then detail the MaxQuant workflow for protein identification and quantification for the PPI data derived from the AP-MS experiment. Finally, we describe the CRAPome interface to process the data by filtering against contaminant lists, score the interactions and visualize the protein interaction networks.
    Matched MeSH terms: Tandem Mass Spectrometry*
  13. The occurrence and probabilistic risk of exposure to parabens from bottled and hand-shaken teas in the general adult population of Taiwan
    Chin WS, Chang CH, Say YH, Chuang YN, Wang JN, Kao HC, et al.
    Environ Sci Pollut Res Int, 2024 Jan;31(3):4518-4527.
    PMID: 38102436 DOI: 10.1007/s11356-023-31348-0
    Parabens (PBs) are esters of p-hydroxybenzoic acid, and there are growing concerns due to their potential to disrupt endocrine function and their wide use as preservatives in foodstuffs, including beverages. The consumption of bottled and hand-shaken teas is gradually replacing traditional tea consumption through brewing. However, no study has reported PB concentrations in different types of teas or packaging and their associated health risks. Our aim was to determine the concentration of PBs (methyl- (MetPB), ethyl- (EthPB), propyl- (PropPB), butyl-paraben (ButPB)) in green, black, and oolong teas in two varieties of products (bottled and hand-shaken teas), using UPLC-MS/MS. Additionally, we estimated the health risks associated with tea consumption in the general adult population of Taiwan. A Monte Carlo simulation was applied to estimate the distribution of daily PB intake through bottled (n = 79) and hand-shaken (n = 71) tea consumption. Our findings revealed geometric mean concentrations in bottled green/black/oolong teas were 714.1/631.2/532.1 ng/L for MetPB, 95.2/ 30.5/14.9 ng/L for EthPB, 77.9/28.3/non-detected (ND) ng/L for PropPB, and 69.3/26.6/ND ng/L for ButPB. Hand-shaken green/black/oolong teas exhibited concentrations of 867.5/2258/1307 ng/L for MetPB, 28.5/28.8/14.5 ng/L for EthPB, 25.4/18.3/17.8 ng/L for PropPB, and 30.3/18.0/15.5 ng/L for ButPB. The median MetPB concentrations in hand-shaken black (2333 ng/L) and oolong teas (1215 ng/L) were significantly higher than those in bottled black (595.4 ng/L) and oolong teas (489.3 ng/L). Conversely, median concentrations of EthPB, PropPB, and ButPB in bottled teas were significantly higher than those in hand-shaken teas. MetPB was the predominant PB, constituting 73.2-91.9% in bottled teas and 85-94% in hand-shaken teas. Our results showed no health risks associated with bottled or hand-shaken tea consumption based on reference doses. However, the study highlights the importance of continued vigilance given the potential chronic exposure to PBs from various sources, necessitating ongoing concern despite the absence of immediate risks from tea consumption.
    Matched MeSH terms: Tandem Mass Spectrometry*
  14. Exploring the binding mechanisms of thermally and ultrasonically induced molten globule-like β-lactoglobulin with heptanal as revealed by multi-spectroscopic techniques and molecular simulation
    Han C, Zheng Y, Huang S, Xu L, Zhou C, Sun Y, et al.
    Int J Biol Macromol, 2024 Apr;263(Pt 1):130300.
    PMID: 38395276 DOI: 10.1016/j.ijbiomac.2024.130300
    This work employed the model protein β-lactoglobulin (BLG) to investigate the contribution of microstructural changes to regulating the interaction patterns between protein and flavor compounds through employing computer simulation and multi-spectroscopic techniques. The formation of molten globule (MG) state-like protein during the conformational evolution of BLG, in response to ultrasonic (UC) and heat (HT) treatments, was revealed through multi-spectroscopic characterization. Differential MG structures were distinguished by variations in surface hydrophobicity and the microenvironment of tryptophan residues. Fluorescence quenching measurements indicated that the formation of MG enhanced the binding affinity of heptanal to protein. LC-MS/MS and NMR revealed the covalent bonding between heptanal and BLG formed by Michael addition and Schiff-base reactions, and MG-like BLG exhibited fewer chemical shift residues. Molecular docking and molecular dynamics simulation confirmed the synergistic involvement of hydrophobic interactions and hydrogen bonds in shaping BLG-heptanal complexes thus promoting the stability of BLG structures. These findings indicated that the production of BLG-heptanal complexes was driven synergistically by non-covalent and covalent bonds, and their interaction processes were influenced by processes-induced formation of MG potentially tuning the release and retention behaviors of flavor compounds.
    Matched MeSH terms: Tandem Mass Spectrometry*
  15. Extraction and identification of biologically important proteins from the medicinal plant God's crown (Phaleria macrocarpa)
    Habib MAH, Ismail MN
    J Food Biochem, 2021 07;45(7):e13817.
    PMID: 34137461 DOI: 10.1111/jfbc.13817
    The fruit and leaf of God's crown (Phaleria macrocarpa) have been traditionally used to treat a wide variety of diseases. However, the proteins of this tropical plant are still heavily understudied. Three protein extraction methods; phenol (Phe), trichloroacetic acid (TCA)-acetone-phenol (TCA-A-Phe), and ultrasonic (Ult) were compared on the fruit and leaf of P. macrocarpa. The Phe extraction method showed the highest percentage of recovered protein after the resolubilization process for both leaf (12.24%) and fruit (30.41%) based on protein yields of the leaf (6.15 mg/g) and fruit (36.98 mg/g). Phe and TCA-A-Phe extraction methods gave well-resolved bands over a wide range of molecular weights through sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Following liquid chromatography-tandem mass spectrometry analysis, proteins identified through the Phe extraction method were 30%-35% enzymatic proteins, including oxidoreductases, transferases, hydrolases, lyases, isomerases, and ligases that possess various biological functions. PRACTICAL APPLICATIONS: Every part of God's crown plant is traditionally consumed to treat various illnesses. While plant's benefits are well known and have led to a plethora of health products, the proteome remains mostly unknown. This study compares three protein extraction methods for the leaf and fruit of P. macrocarpa and identifies their proteins thru LC-MS/MS coupled with PEAKS. These method comparisons can be a guide for works on other plants as well. In addition, the proteomics data from this study may shed light on the functional properties of these plant parts and their products.
    Matched MeSH terms: Tandem Mass Spectrometry
  16. Discovery of microcystin-producing Anagnostidinema pseudacutissimum from cryopreserved Antarctic cyanobacterial mats
    Zaki S, Merican F, Muangmai N, Convey P, Broady P
    Harmful Algae, 2020 03;93:101800.
    PMID: 32307064 DOI: 10.1016/j.hal.2020.101800
    Microcystins (MCs) are secondary metabolites produced by cyanobacteria and have been well-documented in temperate and tropical regions. However, knowledge of the production of MCs in extremely cold environments is still in its infancy. Recently, examination of 100-year-old Antarctic cyanobacterial mats collected from Ross Island and the McMurdo Ice Shelf during Captain R.F. Scott's Discovery Expedition revealed that the presence of MCs in Antarctica is not a new phenomenon. Here, morphological and molecular phylogenetic analyses are used to identify a new microcystin-producing freshwater cyanobacterium, Anagnostidinema pseudacutissimum. The strain was isolated from a deep-frozen (-15 °C) sample collected from a red-brown cyanobacterial mat in a frozen pond at Cape Crozier (Ross Island, continental Antarctica) in 1984-1985. Amplification of the mcyE gene fragment involved in microcystin biosynthesis from A. pseudacutissimum confirmed that it is identical to the sequence from other known microcystin-producing cyanobacteria. Analysis of extracts from this A. pseudacutissimum strain by HPLC-MS/MS confirmed the presence of MC-LR and -YR at concentrations of 0.60 μg/L and MC-RR at concentrations of 0.20 μg/L. This is the first report of microcystin production from a species of Anagnostidinema from Antarctica.
    Matched MeSH terms: Tandem Mass Spectrometry
  17. Fulltext Distinct metabolic signatures in blood plasma of bisphenol A-exposed women with polycystic ovarian syndrome
    Prabhu NB, Vasishta S, Bhat SK, Joshi MB, Kabekkodu SP, Satyamoorthy K, et al.
    Environ Sci Pollut Res Int, 2023 May;30(23):64025-64035.
    PMID: 37060405 DOI: 10.1007/s11356-023-26820-w
    Polycystic ovarian syndrome (PCOS) is a complicated endocrinopathy with an unclear etiology that afflicts fertility status in women. Although the underlying causes and pathophysiology of PCOS are not completely understood, it is suspected to be driven by environmental factors as well as genetic and epigenetic factors. Bisphenol A (BPA) is a weak estrogenic endocrine disruptor known to cause adverse reproductive outcomes in women. A growing relevance supports the notion that BPA may contribute to PCOS pathogenesis. Due to the indeterminate molecular mechanisms of BPA in PCOS endocrinopathy, we sought liquid chromatography with tandem mass spectrometry (LC-MS/MS), a metabolomics strategy that could generate a metabolic signature based on urinary BPA levels of PCOS and healthy individuals. Towards this, we examined urinary BPA levels in PCOS and healthy women by ELISA and performed univariate and chemometric analysis to distinguish metabolic patterns among high and low BPA in PCOS and healthy females, followed by pathway and biomarker analysis employing MetaboAnalyst 5.0. Our findings indicated aberrant levels of certain steroids, sphingolipids, and others, implying considerable disturbances in steroid hormone biosynthesis, linoleic, linolenic, sphingolipid metabolism, and various other pathways across target groups in comparison to healthy women with low BPA levels. Collectively, our findings provide insight into metabolic signatures of BPA-exposed PCOS women, which can potentially improve management strategies and precision medicine.
    Matched MeSH terms: Tandem Mass Spectrometry
  18. Windows Scanning Multiomics: Integrated Metabolomics and Proteomics
    Shi J, Zhao J, Zhang Y, Wang Y, Tan CP, Xu YJ, et al.
    Anal Chem, 2023 Dec 26;95(51):18793-18802.
    PMID: 38095040 DOI: 10.1021/acs.analchem.3c03785
    Metabolomics and proteomics offer significant advantages in understanding biological mechanisms at two hierarchical levels. However, conventional single omics analysis faces challenges due to the high demand for specimens and the complexity of intrinsic associations. To obtain comprehensive and accurate system biological information, we developed a multiomics analytical method called Windows Scanning Multiomics (WSM). In this method, we performed simultaneous extraction of metabolites and proteins from the same sample, resulting in a 10% increase in the coverage of the identified biomolecules. Both metabolomics and proteomics analyses were conducted by using ultrahigh-performance liquid chromatography mass spectrometry (UPLC-MS), eliminating the need for instrument conversions. Additionally, we designed an R-based program (WSM.R) to integrate mathematical and biological correlations between metabolites and proteins into a correlation network. The network created from simultaneously extracted biomolecules was more focused and comprehensive compared to those from separate extractions. Notably, we excluded six pairs of false-positive relationships between metabolites and proteins in the network established using simultaneously extracted biomolecules. In conclusion, this study introduces a novel approach for multiomics analysis and data processing that greatly aids in bioinformation mining from multiomics results. This method is poised to play an indispensable role in systems biology research.
    Matched MeSH terms: Tandem Mass Spectrometry
  19. Determination of aflatoxins in rice from Penang, Malaysia by dispersive liquid-liquid micro-extraction and LC-MS/MS
    Salim SA, Baharudin NH, Ibrahim NS, Abd Ghani Z, Ismail MN
    Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2024 May;41(5):563-574.
    PMID: 38527182 DOI: 10.1080/19440049.2024.2329614
    Rice is one of the crops cultivated in Malaysia, and it is the main diet for most of the population. In this study, dispersive liquid-liquid micro-extraction (DLLME) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were used to develop, optimise and validate a reliable, easy-to-use and quick approach to detect aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1) and aflatoxin G2 (AFG2). The extraction recoveries in DLLME were enhanced by the addition of 5% salt, utilising chloroform as the extraction solvent and acetonitrile as the dispersive solvent. The DLLME parameters - the extraction solvent volume, salt concentration and dispersive solvent volume were optimised with Box-Behnken design (BBD) and response surface methodology (RSM). Under optimised experimental conditions, excellent linearity was obtained with a limit of detection (LOD) ranging from 0.125 to 0.25 ng g-1, a limit of quantitation (LOQ) ranging from 0.25 to 0.3 ng g-1 and a correlation value (R2) of 0.990. The matrix effects were between -11.1% and 19.9%, and recoveries ranged from 87.4% to 117.3%. The optimised and validated method was used effectively to assess aflatoxins contamination in 20 commercial rice samples collected from local supermarkets in Penang, Malaysia. AFB1 was detected at 0.41-0.43 ng g-1 in two rice samples, below the regulatory limit.
    Matched MeSH terms: Tandem Mass Spectrometry
  20. 1H NMR-based metabolomics and UHPLC-ESI-MS/MS for the investigation of bioactive compounds from Lupinus albus fractions
    Hellal K, Mediani A, Ismail IS, Tan CP, Abas F
    Food Res Int, 2021 02;140:110046.
    PMID: 33648271 DOI: 10.1016/j.foodres.2020.110046
    Lupinus albus or white lupine has recently received increase attention for its medicinal values. Several studies have described the hypoglycemic effect of the white lupine, which is known as a food plant with potential value for treatment of diabetes. This study provides useful information for the identification and quantification of compounds in L. albus fractions by proton nuclear magnetic resonance (1H NMR) spectroscopy. In total, 35 metabolites were identified from L. albus fractions.Principal component analysis (PCA) was used as a multivariate projection method for visualizing the different composition of four different fractions. The bioactivities of fractions with different polarity obtained from the extract of L. albus seeds are reported. Among the fractions studied, the chloroform fraction (CF) exhibits a high free radical scavenging (DPPH) and α-glucosidase inhibitory activities with IC50 values of 24.08 and 20.08 μg/mL, respectively. A partial least-squares analyses (PLS) model had been successfully performed to correlate the potential active metabolites with the corresponding biological activities. Metabolites containing proline, caprate, asparagine, lupinoisolone C, hydroxyiso lupalbigenin and some unknown compounds show high correlation with the bioactivities studied. Moreover, the structural identification in the active fraction was supported by ultrahigh-performance-liquid chromatography-electrospray ionization tandem mass spectrometry (UHPLC-ESI-MS/MS) analysis. A total of 21 metabolites were tentatively identified from MS/MS data by comparison with previously reported data. Most of these compounds are isoflavonoids without known biological activity. This information may be useful for developing functional food from L. albus with potential application in the management of diabetes.
    Matched MeSH terms: Tandem Mass Spectrometry*
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