Displaying publications 321 - 340 of 961 in total

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  1. Chung YS, Choo BKM, Ahmed PK, Othman I, Shaikh MF
    Biomedicines, 2020 Jul 02;8(7).
    PMID: 32630817 DOI: 10.3390/biomedicines8070191
    The anticonvulsive potential of proteins extracted from Orthosiphon stamineus leaves (OSLP) has never been elucidated in zebrafish (Danio rerio). This study thus aims to elucidate the anticonvulsive potential of OSLP in pentylenetetrazol (PTZ)-induced seizure model. Physical changes (seizure score and seizure onset time, behavior, locomotor) and neurotransmitter analysis were elucidated to assess the pharmacological activity. The protective mechanism of OSLP on brain was also studied using mass spectrometry-based label-free proteomic quantification (LFQ) and bioinformatics. OSLP was found to be safe up to 800 µg/kg and pre-treatment with OSLP (800 µg/kg, i.p., 30 min) decreased the frequency of convulsive activities (lower seizure score and prolonged seizure onset time), improved locomotor behaviors (reduced erratic swimming movements and bottom-dwelling habit), and lowered the excitatory neurotransmitter (glutamate). Pre-treatment with OSLP increased protein Complexin 2 (Cplx 2) expression in the zebrafish brain. Cplx2 is an important regulator in the trans-SNARE complex which is required during the vesicle priming phase in the calcium-dependent synaptic vesicle exocytosis. Findings in this study collectively suggests that OSLP could be regulating the release of neurotransmitters via calcium-dependent synaptic vesicle exocytosis mediated by the "Synaptic Vesicle Cycle" pathway. OSLP's anticonvulsive actions could be acting differently from diazepam (DZP) and with that, it might not produce the similar cognitive insults such as DZP.
    Matched MeSH terms: Mass Spectrometry
  2. Kumarasamy G, Abdus Sani AA, Olivos-García A, Noordin R, Othman N
    Pathog Glob Health, 2020 09;114(6):333-342.
    PMID: 32536281 DOI: 10.1080/20477724.2020.1780402
    Amoebiasis, caused by Entamoeba histolytica, is one of the leading parasitic infections in the world. This study was aimed at profiling antigenic membrane proteins of a virulent variant of E. histolytica HM-1:IMSS. The membrane proteins were extracted using ProteoExtract® kit (Merck, Darmstadt, Germany) or conventional method, separated using OFFGEL 3100 fractionator (Agilent Technologies, Santa Clara, California), followed by SDS-PAGE and Western blot analysis. Selected antigenic membrane proteins were identified using LC-ESI-MS/MS. Subsequently, the proteins were classified according to their biological processes and predictions were made on membrane and membrane-associated proteins. When the proteins were probed with pooled sera from amoebic liver abscess (ALA) patients, 10 and 15 antigenic proteins with molecular weights 25 to 200 kDa were identified using the ProteoExtract® kit and conventional method, respectively. LC-ESI-MS/MS identified 13 antigenic proteins, and both extraction methods predicted six of them as membrane and membrane-associated proteins. The topmost biological processes which comprised of six proteins were involved in cellular processes.. These antigenic membrane proteins merit further investigations as potential candidates for vaccine studies.
    Matched MeSH terms: Tandem Mass Spectrometry
  3. Abdul Rahman M, Mohamad Haron DE, Hollows RJ, Abdul Ghani ZDF, Ali Mohd M, Chai WL, et al.
    PeerJ, 2020;8:e9304.
    PMID: 32547888 DOI: 10.7717/peerj.9304
    Head and neck squamous cell carcinoma (HNSCC) represents a significant world health problem, with approximately 600,000 new cases being diagnosed annually. The prognosis for patients with HNSCC is poor and, therefore, the identification of biomarkers for screening, diagnosis and prognostication would be clinically beneficial. A limited number of studies have used lipidomics to profile lipid species in the plasma of cancer patients. However, the profile and levels of lysophosphatidic acid (LPA) species have not been examined in HNSCC. In this study, a targeted lipidomics approach using liquid chromatography triple quadrupole mass spectrometry (LCMS/MS) was used to analyse the concentration of LPA (16:0 LPA, 18:0 LPA, 18:1 LPA, 18:2 LPA and 20:4 LPA) in the plasma of patients with oral squamous cell carcinoma (OSCC) and nasopharyngeal carcinoma (NPC), together with healthy controls. The levels of three LPA species (18:1 LPA, 18:2 LPA and 20:4 LPA) were significantly lower in the plasma of OSCC patients, whilst the concentrations of all five LPA species tested were significantly lower in plasma from NPC patients. Furthermore, the order of abundance of LPA species in plasma was different between the control and cancer groups, with 16:0 LPA, 18:0 LPA levels being more abundant in OSCC and NPC patients. Medium to strong correlations were observed using all pairs of LPA species and a clear separation of the normal and tumour groups was observed using PCA analysis. In summary, the results of this study showed that the levels of several LPA species in the plasma of patients with OSCC and NPC were lower than those from healthy individuals. Understanding these variations may provide novel insights into the role of LPA in these cancers.
    Matched MeSH terms: Mass Spectrometry
  4. Fletcher MT, Hungerford NL, Webber D, Carpinelli de Jesus M, Zhang J, Stone ISJ, et al.
    Sci Rep, 2020 07 22;10(1):12128.
    PMID: 32699353 DOI: 10.1038/s41598-020-68940-0
    Stingless bee (Meliponini) honey has long been considered a high-value functional food, but the perceived therapeutic value has lacked attribution to specific bioactive components. Examination of honey from five different stingless bee species across Neotropical and Indo-Australian regions has enabled for the first time the identification of the unusual disaccharide trehalulose as a major component representing between 13 and 44 g per 100 g of each of these honeys. Trehalulose is an isomer of sucrose with an unusual α-(1 → 1) glucose-fructose glycosidic linkage and known acariogenic and low glycemic index properties. NMR and UPLC-MS/MS analysis unambiguously confirmed the identity of trehalulose isolated from stingless bee honeys sourced across three continents, from Tetragonula carbonaria and Tetragonula hockingsi species in Australia, from Geniotrigona thoracica and Heterotrigona itama in Malaysia and from Tetragonisca angustula in Brazil. The previously unrecognised abundance of trehalulose in stingless bee honeys is concrete evidence that supports some of the reported health attributes of this product. This is the first identification of trehalulose as a major component within a food commodity. This study allows the exploration of the expanded use of stingless bee honey in foods and identifies a bioactive marker for authentication of this honey in associated food standards.
    Matched MeSH terms: Tandem Mass Spectrometry
  5. Subuhi NEAM, Saad SM, Zain NNM, Lim V, Miskam M, Kamaruzaman S, et al.
    J Sep Sci, 2020 Aug;43(16):3294-3303.
    PMID: 32519432 DOI: 10.1002/jssc.201901194
    In this work, a simple, fast, sensitive, and environmentally friendly method was developed for preconcentration and quantitative measurement of bisphenol A in water samples using gas chromatography with mass spectrometry. The preconcentration approach, namely biosorption-based dispersive liquid-liquid microextraction with extractant removal by magnetic nanoparticles was performed based on the formation of microdroplet of rhamnolipid biosurfactant throughout the aqueous samples, which accelerates the mass transfer process between the extraction solvent and sample solution. The process is then followed by the application of magnetic nanoparticles for easy retrieval of the analyte-containing extraction solvent. Several important variables were optimized comprehensively including type of disperser solvent and desorption solvent, rhamnolipid concentration, volume of disperser solvent, amount of magnetic nanoparticles, extraction time, desorption time, ionic strength, and sample pH. Under the optimized microextraction and gas chromatography with mass spectrometry conditions, the method demonstrated good linearity over the range of 0.5-500 µg/L with a coefficient of determination of R2  = 0.9904, low limit of detection (0.15 µg/L) and limit of quantification (0.50 µg/L) of bisphenol A, good analyte recoveries (84-120%) and acceptable relative standard deviation (1.8-14.9%, n = 6). The proposed method was successfully applied to three environmental water samples, and bisphenol A was detected in all samples.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  6. Hamada T, Harano K, Niihara R, Kitahara H, Yamamoto M, Vairrapan CS, et al.
    J Oleo Sci, 2020;69(6):643-648.
    PMID: 32493886 DOI: 10.5650/jos.ess19296
    Sour citrus are prized for their flavor and fragrance. This work identified the components of the peel oil of Hetsuka-daidai (Citrus sp. hetsukadaidai), a special sour citrus that is native to the southern part of the Osumi peninsula, Kagoshima, Japan. These compounds were compared to those identified from the peels of six other major sour citrus: lime (Citrus latifolia), lemon (Citrus limon), Yuzu (Citrus junos), Kabusu (Citrus aurantium), Kabosu (Citrus sphaerocarpa), and Sudachi (Citrus sudachi). Peel oil contents were analyzed for the duration of four months during harvest season to investigate the differences in peel oil/fragrance during ripening. These results could facilitate the development of preferred flavor and scent profiles using local species.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  7. Sew YS, Aizat WM, Razak MSFA, Zainal-Abidin RA, Simoh S, Abu-Bakar N
    Data Brief, 2020 Aug;31:105927.
    PMID: 32642524 DOI: 10.1016/j.dib.2020.105927
    The proteome data of whole rice grain is considerably limited particularly for rice with pigmentations such as black and red rice. Hence, we performed proteome analysis of two black rice varieties (BALI and Pulut Hitam 9), two red rice varieties (MRM16 and MRQ100) and two white rice varieties (MR297 and MRQ76) using label-free liquid chromatography Triple TOF 6600 tandem mass spectrometry (LC-MS/MS). Our aim was to profile and identify proteins related to nutritional (i.e. antioxidant, folate and low glycaemic index) and quality (i.e. aromatic) traits based on peptide-centric scoring from the Sequential Window Acquisition of All Theoretical Mass Spectra (SWATH-MS) approach. Both information dependent acquisition (IDA) and SWATH-MS run were performed in this analysis. Raw data was then processed using ProteinPilot software to identify and compare proteins from the six different varieties. In future, this proteomics data will be integrated with previously obtained genomics [1] and transcriptomics [2] data focusing on the above nutritional and quality traits, with an ultimate aim to develop a panel of functional biomarkers related to those traits for future rice breeding programme. The raw MS data of the pigmented and non-pigmented rice varieties have been deposited to ProteomeXchange database with accession number PXD018338.
    Matched MeSH terms: Tandem Mass Spectrometry
  8. Chen YL, Shi L, Agbo F, Yong SH, Tan PS, Ngounou Wetie AG
    J Pharm Biomed Anal, 2020 Oct 25;190:113493.
    PMID: 32795778 DOI: 10.1016/j.jpba.2020.113493
    A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the simultaneous quantification of apomorphine and its metabolites apomorphine sulfate and norapomorphine in human plasma for supporting clinical development of a novel apomorphine sublingual thin film (APL) for the treatment of Parkinson's disease. Analytes and internal standards (IS) were extracted from human plasma by Oasis HLB SPE cartridge, followed by a reversed phase LC-MS/MS analysis using multiple reaction monitoring (MRM) in positive mode (m/z 268 → 237 for apomorphine, 348 → 237 for apomorphine sulfate, and 348 → 237 for norapomorphine). Stable isotope-labeled compounds were used as IS for respective analytes. The validated curve ranges were 0.02-20 ng/mL, 10-1000 ng/mL, and 0.5-20 ng/mL for apomorphine, apomorphine sulfate and norapomorphine, respectively. Extraction recoveries were found to be 73.4 % (apomorphine), 81.1 % (apomorphine sulfate), and 58.6 % (norapomorphine). Established long-term plasma frozen storage stabilities were 504 days at -20 °C and276 days at -60 °C, respectively. The method has been successfully used for analyzing pharmacokinetics (PK) samples collected from a comparative bioavailability study of APL and the marketed apomorphine subcutaneous (s.c.) product Apo-go®. The results demonstrated that the 15-mg APL film administrated via sublingual produced comparable PK characteristics of apomorphine when compared to the commercial product Apo-go (2-mg) via s.c. administration, hence establishing the dose regimen for this sublingual formulation. It was also noticed that the sublingual 15-mg APL film produced a significantly higher apomorphine sulfate metabolite level than the 2-mg s.c. Apo-go, and both treatments yielded a negligible level of norapomorphine metabolite in humans.
    Matched MeSH terms: Tandem Mass Spectrometry
  9. Balasubramaniam V, June Chelyn L, Vimala S, Mohd Fairulnizal MN, Brownlee IA, Amin I
    Heliyon, 2020 Aug;6(8):e04654.
    PMID: 32817893 DOI: 10.1016/j.heliyon.2020.e04654
    Three species of Malaysian edible seaweed (Eucheuma denticulatum, Sargassum polycystum and Caulerpa lentillifera) were analyzed for their carotenoid composition using a combination of high-performance thin layer chromatography (HPTLC) and ultra-high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UHPLC-ESI-MS/MS), while the antioxidant capacities were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) assays. The HPTLC analysis exhibited a distinct carotenoid pattern among the three seaweed groups. The UHPLC-ESI-MS/MS analysis showed fucoxanthin as the major carotenoid present in S. polycystum while lutein and zeaxanthin in E. denticulatum. For C. lentillifera, β-carotene and canthaxanthin were the major carotenoids. Some of the carotenoids, such as rubixanthin, dinoxanthin, diatoxanthin and antheraxanthin, were also tentatively detected in E. denticulatum and S. polycystum. For antioxidant activity, S. polycystum (20 %) and E. denticulatum (1128 μmol TE/g) showed the highest activity in the DPPH and ORAC assays, respectively. The findings suggest the three edible varieties of seaweeds may provide a good dietary source with a potential to reduce antioxidative stress.
    Matched MeSH terms: Tandem Mass Spectrometry
  10. Syaidatul Faraha Zainuddin, Siti Raihan Zakaria, Norashikin Saim, Rossuriati Dol Hamid, Rozita Osman
    Science Letters, 2020;14(2):58-70.
    MyJurnal
    Headspace solid phase microextraction (HS-SPME) was employed for the extraction of volatile organic compounds (VOCs) in MD2 pineapple (Ananas comosus L. var. comosus cv. MD2). Optimisation of HS-SPME operating parameters was conducted using three-factor, three-level Box–Behnken response surface experimental design to evaluate the interactive effects of temperature (30 – 50 ºC), extraction time (10 – 30 min) and salting effect (1 – 3 g of salt addition) on the amount of selected VOCs. Determination of VOCs was done using gas chromatography with spectrometry detector (GC-MSD). Extraction temperature was found to be significant (p < 0.05) in increasing the amount of selected VOCs (ethyl acetate, methyl isobutyrate and butanoic acid methyl ester). Based on the maximum amount of these VOCs, the optimum operating extraction conditions for HS-SPME were set up at temperature of 30 °C, time of 29 min and salt addition of 1 g. The optimized HS-SPME conditions were employed for the extraction of VOCs from pineapple of different varieties.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  11. Sundralingam U, Chakravarthi S, Radhakrishnan AK, Muniyandy S, Palanisamy UD
    Pharmaceutics, 2020 Aug 25;12(9).
    PMID: 32854385 DOI: 10.3390/pharmaceutics12090807
    Oral tamoxifen used in the prevention and treatment of ductal carcinoma in situ (DCIS) (estrogen-positive) patients has limited acceptance, due to its adverse side effects. The efficacy of tamoxifen is related to its major metabolite, 4-hydroxytamoxifen. Local transdermal therapy of 4-hydroxytamoxifen to the breast might avert the toxicity of oral tamoxifen, while maintaining efficacy. We aim to study the skin irritancy, as well as to evaluate the efficacy of the developed transfersome formulations, with/without emu oil, using a syngeneic mouse model of breast cancer. We also quantified tamoxifen/4-hydroxytamoxifen concentrations in blood plasma and performed histopathology. The skin irritancy test showed that the pure emu oil and transfersome formulations with or without the emu oil did not cause skin irritancy in the animals studied. A sensitive and specific LC-MS/MS method for the quantification of tamoxifen and 4-hydroxytamoxifen was developed and validated. Studies on tumor volume and necrosis (histopathology) using the breast cancer mouse model showed that the 4-OHT transfersomal formulations, with and without emu oil, showed comparable efficacy with that of orally administered tamoxifen. However, the transfersomal formulations, with and without emu oil, resulted in significantly lower (10.24 ± 0.07 and 32.45 ± 0.48 ng/mL, respectively) plasma concentrations of 4-hydroxytamoxifen, compared to the oral tamoxifen (TAMX) group (634.42 ± 7.54 ng/mL). This study demonstrated the potential use of emu oil in a local transdermal formulation for the treatment of breast cancer and its reduced adverse effects.
    Matched MeSH terms: Tandem Mass Spectrometry
  12. Ahmadu T, Ahmad K, Ismail SI, Rashed O, Asib N, Omar D
    Braz J Biol, 2020 11 12;81(4):1007-1022.
    PMID: 33175006 DOI: 10.1590/1519-6984.233173
    Drawbacks associated with the use of chemical fungicides to control plant pathogenic fungi such as Botrytis cinerea stimulate the need for alternatives. Therefore, the present study was carried out to determine the antifungal potentials of Moringa oleifera extracts against B. cinerea. Phytochemical analysis using qualitative chemical tests revealed the presence of huge amount of crucial phytochemicals compounds like phenolic compounds, alkaloids and saponins in the M. oleifera leaf extract. Antifungal bioassay of the crude extracts indicated better mycelial growth inhibition by methanol leaf extract (99%). The minimum inhibitory concentration (MIC) was 5 mg/ml with 100% spore germination inhibition and minimum fungicidal concentration (MFC) was 10 mg/ml with 98.10% mycelial growth inhibition using broth micro dilution and poisoned food techniques. Gas chromatography-mass spectrometry (GC-MS) analysis led to the identification of 67 volatile chemical compounds in the leaf extract with 6-decenoic acid (Z)- (19.87%) was the predominant compound. Further chemical elucidation of the crude extracts performed by liquid chromatography with tandem mass spectrometry (LC-MS/MS) showed the presence of non-volatile chemical compounds, mostly flavones, flavonoids and phenolic acids (i.e. quercetin and kaempferol). Scanning electron microscopy and transmission electron microscopy analysis showed positive effect of M. oleifera leaf extract on the treated conidia and mycelium of B. cinerea. Findings revealed that irreversible surface and ultra-structural changes with severe detrimental effects on conidia and mycelium morphology compared to control treatment. Overall findings suggested that M. oleifera leaf extract is a promising candidate for biological control of fungal pathogens, thus limiting overdependence on chemical fungicides.
    Matched MeSH terms: Tandem Mass Spectrometry
  13. Chen XM, Pang JX, Huang CX, Lundholm N, Teng ST, Li A, et al.
    J Phycol, 2021 Feb;57(1):335-344.
    PMID: 33174223 DOI: 10.1111/jpy.13101
    To explore the species diversity and toxin profile of Pseudo-nitzschia, monoclonal strains were established from Chinese southeast coastal waters. The morphology was examined under light and transmission electron microscopy. The internal transcribed spacer region of ribosomal DNA was sequenced for phylogenetic analyses, and the secondary structure of ITS2 was predicted and compared among allied taxa. A combination of morphological and molecular data showed the presence of two new species, Pseudo-nitzschia hainanensis sp. nov. and Pseudo-nitzschia taiwanensis sp. nov. Pseudo-nitzschia hainanensis was characterized by a dumpy-lanceolate valve with slightly blunt apices and a central nodule, as well as striae comprising two rows of poroids. Pseudo-nitzschia taiwanensis was characterized by a slender-lanceolate valve, and striae comprising one row of split poroids. The poroid structure mainly comprised two sectors. Both taxa constituted their own monophyletic lineage in the phylogenetic analyses inferred from ITS2 rDNA and were well differentiated from other Pseudo-nitzschia species. Morphologically, P. hainanensis and P. taiwanensis could be assigned to the Pseudo-nitzschia delicatissima and the Pseudo-nitzschia pseudodelicatissima complex, respectively. Particulate domoic acid was measured using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS), but no detectable pDA was found. With the description of the two new species, the species diversity of genus Pseudo-nitzschia reaches 58 worldwide, among which 31 have been recorded from Chinese coastal waters.
    Matched MeSH terms: Tandem Mass Spectrometry
  14. Tey HY, See HH
    J Chromatogr A, 2021 Jan 04;1635:461731.
    PMID: 33285415 DOI: 10.1016/j.chroma.2020.461731
    Conventional sampling of biological fluids often involves a bulk quantity of samples that are tedious to collect, deliver and process. Miniaturized sampling approaches have emerged as promising tools for sample collection due to numerous advantages such as minute sample size, patient friendliness and ease of shipment. This article reviews the applications and advances of microsampling techniques in therapeutic drug monitoring (TDM), covering the period January 2015 - August 2020. As whole blood is the gold standard sampling matrix for TDM, this article comprehensively highlights the most historical microsampling technique, the dried blood spot (DBS), and its development. Advanced developments of DBS, ranging from various automation DBS, paper spray mass spectrometry (PS-MS), 3D dried blood spheroids and volumetric absorptive paper disc (VAPD) and mini-disc (VAPDmini) are discussed. The volumetric absorptive microsampling (VAMS) approach, which overcomes the hematocrit effect associated with the DBS sample, has been employed in recent TDM. The sample collection and sample preparation details in DBS and VAMS are outlined and summarized. This review also delineates the involvement of other biological fluids (plasma, urine, breast milk and saliva) and their miniaturized dried matrix forms in TDM. Specific features and challenges of each microsampling technique are identified and comparison studies are reviewed.
    Matched MeSH terms: Mass Spectrometry
  15. Kok SY, Namasivayam P, Ee GC, Ong-Abdullah M
    J Proteomics, 2021 02 10;232:104052.
    PMID: 33262095 DOI: 10.1016/j.jprot.2020.104052
    To gain insights on protein changes in fruit setting and growth in oil palm, a comparative proteomic approach was undertaken to study proteome changes during its early development. The variations in the proteome at five early developmental stages were investigated via a gel-based proteomic technique. A total of 129 variant proteins were determined using mass spectrometric analysis, resulting in 80 identifications. The majority of the identified protein species were classified as energy and metabolism, stress response/defence and cell structure during early oil palm development representing potential candidates for the control of final fruit size and composition. Seven prominent protein species were then characterised using real-time polymerase chain reaction to validate the mRNA expression against the protein abundant profiles. Transcript and protein profiles were parallel across the developmental stages, but divergent expression was observed in one protein spot, indicative of possible post-transcriptional events. Our results revealed protein changes in early oil palm fruit development provide valuable information in the understanding of fruit growth and metabolism during early stages that may contribute towards improving agronomic traits. BIOLOGICAL SIGNIFICANCE: Two-dimensional gel electrophoresis coupled with mass spectrometry approach was used in this study to identify differentially expressed proteins during early oil palm fruit development. A total of 80 protein spots with significant change in abundance were successfully identified and selected genes were analysed using real time PCR to validate their expression. The dynamic changes in oil palm fruit proteome during early development were mostly active in primary and energy metabolism, stress responses, cell structure and protein metabolism. This study reveals the physiological processes during early oil palm fruit development and provides a reference proteome for further improvements in fruit quality traits.
    Matched MeSH terms: Mass Spectrometry
  16. Solayman M, Islam MA, Paul S, Ali Y, Khalil MI, Alam N, et al.
    Compr Rev Food Sci Food Saf, 2016 Jan;15(1):219-233.
    PMID: 33371579 DOI: 10.1111/1541-4337.12182
    Honey is a popular natural food product with a very complex composition mainly consisting of both organic and inorganic constituents. The composition of honey is strongly influenced by both natural and anthropogenic factors, which vary based on its botanical and geographical origins. Although minerals and heavy metals are minor constituents of honey, they play vital role in determining its quality. There are several different analytical methods used to determine the chemical elements in honey. These methods are typically based on spectroscopy or spectrometry techniques (including atomic absorption spectrometry, atomic emission spectrometry, inductively coupled plasma mass spectrometry, and inductively coupled plasma optical emission spectrometry). This review compiles available scientific information on minerals and heavy metals in honey reported from all over the world. To date, 54 chemical elements in various types of honey have been identified and can be divided into 3 groups: major or macroelements (Na, K, Ca, Mg, P, S, Cl), minor or trace elements (Al, Cu, Pb, Zn, Mn, Cd, Tl, Co, Ni, Rb, Ba, Be, Bi, U, V, Fe, Pt, Pd, Te, Hf, Mo, Sn, Sb, La, I, Sm, Tb, Dy, Sd, Th, Pr, Nd, Tm, Yb, Lu, Gd, Ho, Er, Ce, Cr, As, B, Br, Cd, Hg, Se, Sr), and heavy metals (trace elements that have a specific gravity at least 5 times higher than that of water and inorganic sources). Chemical elements in honey samples throughout the world vary in terms of concentrations and are also influenced by environmental pollution.
    Matched MeSH terms: Mass Spectrometry
  17. Appalasamy S, Diyana MHA, Arumugam N, Boon JG
    Sci Rep, 2021 01 08;11(1):153.
    PMID: 33420232 DOI: 10.1038/s41598-020-80018-5
    The use of chemical insecticides has had many adverse effects. This study reports a novel perspective on the application of insect-based compounds to repel and eradicate other insects in a controlled environment. In this work, defense fluid was shown to be a repellent and insecticide against termites and cockroaches and was analyzed using gas chromatography-mass spectrometry (GC-MS). Globitermes sulphureus extract at 20 mg/ml showed the highest repellency for seven days against Macrotermes gilvus and for thirty days against Periplaneta americana. In terms of toxicity, G. sulphureus extract had a low LC50 compared to M. carbonarius extract against M. gilvus. Gas chromatography-mass spectrometry analysis of the M. carbonarius extract indicated the presence of six insecticidal and two repellent compounds in the extract, whereas the G. sulphureus extract contained five insecticidal and three repellent compounds. The most obvious finding was that G. sulphureus defense fluid had higher potential as a natural repellent and termiticide than the M. carbonarius extract. Both defense fluids can play a role as alternatives in the search for new, sustainable, natural repellents and termiticides. Our results demonstrate the potential use of termite defense fluid for pest management, providing repellent and insecticidal activities comparable to those of other green repellent and termiticidal commercial products.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  18. Loh GOK, Wong EYL, Tan YTF, Wee HC, Ng RS, Lee CY, et al.
    J Pharm Biomed Anal, 2021 Feb 05;194:113758.
    PMID: 33248861 DOI: 10.1016/j.jpba.2020.113758
    A simple, rapid, sensitive, and reproducible LC-MS/MS method was developed for simultaneous quantification of flavoxate and 3-methyl-flavone-8-carboxylic (MFCA) in human plasma, using diphenhydramine HCl as internal standard (IS). The chromatographic separation was achieved using Agilent Poroshell 120 EC-C18 - Fast LC column (100 × 2.1mmID, 2.7 μm) fitted with UHPLC Guard Poroshell 120 EC-C18 (5 × 2.1 mmID, 2.7 μm). The mobile phase consisted of 0.1 % v/v formic acid and acetonitrile (30:70, v/v) run at a flow rate of 0.40 mL/min. The standard calibration curve was linear over the concentration range of 2.00 - 2,000.31 ng/mL and 240.00 - 24,000.04 ng/mL for flavoxate and MFCA. For flavoxate and MFCA, the within-run precision was 0.81-6.67 % and 1.68-4.37 %, while accuracy was 100.21-108.25 % and 103.99-110.28 %. The between-run precision was 2.01-9.14 % and 2.31-11.11 %, and accuracy was 96.09-103.33 % and 102.37-109.52 %. The extended run precision was 7.78-11.04 % and 2.22-3.33 %, while accuracy was 100.72-101.88 % and 102.34-105.60 %. Flavoxate and MFCA in plasma were stable 4 h at bench top (short term), 24 h in autosampler and instrumentation room (post-preparative), after 7 freeze-thaw cycles, and 89 days in the freezer. Both analytes and IS stock solutions were stable for 31 days when kept at room temperature (25 ± 4 °C) and refrigerated (2-8 °C). The validated method was successfully applied to a bioequivalence study of two flavoxate formulations involving 24 healthy volunteers.
    Matched MeSH terms: Tandem Mass Spectrometry
  19. Halim N, Kuntom A, Shinde R, Banerjee K
    J AOAC Int, 2020 Sep 01;103(5):1237-1242.
    PMID: 33241391 DOI: 10.1093/jaoacint/qsaa041
    BACKGROUND: Indaziflam (IND) is a herbicide that is used in palm oil plantations for broad spectrum management of weeds. Until now, no validated method has been available for residue estimation of this herbicide in palm oil products.

    OBJECTIVE: In this study, we report a rapid method for the residue analysis of IND and its metabolites, viz., IND-carboxylic acid, diaminotriazine, and triazine indanone in a wide range of palm oil matrices using liquid chromatography-tandem mass spectrometry (LC-MS/MS).

    METHOD: The optimized sample preparation workflows included two options: (1) acetonitrile extraction (QuEChERS workflow), followed by freezing at -80°C and (2) acetonitrile extraction, followed by cleanup through a C18 solid phase extraction (SPE) cartridge. The optimized LC runtime was 7 min. All these analytes were estimated by LC-MS/MS multiple reaction monitoring.

    RESULTS: Both sample preparation methods provided similar method performance and acceptable results. The limit of quantification (LOQ) of IND, IND-carboxylic acid, and triazine indanone was 0.001 mg/kg. For diaminotriazine, the LOQ was 0.005 mg/kg. The method accuracy and precision complied with the SANTE/12682/2019 guidelines of analytical quality control.

    CONCLUSIONS: The potentiality of the method lies in a high throughput analysis of IND and its metabolites in a single chromatographic run with high selectivity and sensitivity. Considering its fit-for-purpose performance, the method can be implemented in regulatory testing of IND residues in a wide range of palm oil matrices that are consumed and traded worldwide.

    HIGHLIGHTS: This work has provided a validated method for simultaneous residue analysis of indaziflam and its metabolites in crude palm oil and its derived matrices with high sensitivity, selectivity, and throughput.

    Matched MeSH terms: Tandem Mass Spectrometry
  20. Shori AB, Muniandy P, Baba AS
    Recent Pat Food Nutr Agric, 2021;12(1):36-44.
    PMID: 33231153 DOI: 10.2174/2212798411999201123205022
    BACKGROUND: Green, white, and black tea water extracts are rich in phenolic compounds.

    OBJECTIVE: The changes in phenolic compound profiles of green, white, and black tea (GT, WT, & BT respectively) water extracts and their respective yogurt were investigated.

    METHODS: Three types of yogurt with tea water extracts were prepared, and the phenolic compound profiles were analyzed using the liquid chromatography-mass spectrometry (LC-MS) method.

    RESULTS: The present data found that flavonol glycosides such as kaempferol-3-rutinoside and quercetin-rhamnosylgalactoside or rutinoside were present in WT extract, whereas catechin derivatives such as gallocatechin (GC) and epigallocatechin (EGC) were present in GT extract. Moreover, theaflavin-3-O-gallate was observed in BT extract. Many of the catechin and its derivatives detected in the tea extracts were not identified in the tea yogurt samples. However, new phenolic compounds were present in GT-yogurt (i.e., kaempferol-3-rutinoside and quinic acid conjugate) but absent in GT extract.

    CONCLUSION: GT, WT, & BT extracts could be used to enriched-yogurt with phenolic compounds, which may have antioxidant properties.

    Matched MeSH terms: Mass Spectrometry
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