Displaying publications 421 - 440 of 951 in total

Abstract:
Sort:
  1. Antidepressant evaluation of Andrographis paniculata Nees extract and andrographolide in chronic unpredictable stress zebrafish model
    Aldurrah Z, Mohd Kauli FS, Abdul Rahim N, Zainal Z, Afzan A, Al Zarzour RH, et al.
    Comp Biochem Physiol C Toxicol Pharmacol, 2023 Sep;271:109678.
    PMID: 37301417 DOI: 10.1016/j.cbpc.2023.109678
    Andrographis paniculata (A. paniculata) showed an anti-depressive effect in rodent models. Zebrafish has recently emerged as a worthy complementary translational model for antidepressant drug discovery study. This study investigates the anti-depressive effect of A. paniculata extract and andrographolide in the chronic unpredictable stress (CUS)- zebrafish model. Four groups of zebrafish (n = 10/group), i.e. control, CUS (stressed, untreated), CUS + A. paniculata (100 mg/L) and CUS + fluoxetine (0.01 mg/L) were assessed in open-field and social interaction tests, 24 h after treatment. After extract screening, behavioural and cortisol analysis of andrographolide (5, 25 and 50 mg/kg, i.p.) and fluoxetine (10 mg/kg, i.p.) were evaluated. Before the behavioural study, acute toxicity and characterization of A. paniculata extract using UHPLC-ESI-MS/MS were performed. A significant reduction in freezing duration was found in A. paniculata- (t-test, p = 0.0234) and fluoxetine-treated groups (t-test, p 
    Matched MeSH terms: Tandem Mass Spectrometry
  2. Molecular docking and molecular dynamic simulations of apoptosis proteins with potential anticancer compounds present in Clinacanthus nutans extract using gas chromatography-mass spectrometry
    Ismail NZ, Mohamed WAS, Ab Rahim N, Hashim NM, Adebayo IA, Mohamad Zain NN, et al.
    J Biomol Struct Dyn, 2023;41(13):6104-6120.
    PMID: 35899385 DOI: 10.1080/07391102.2022.2101530
    Clinacanthus nutans is a medicinal plant recognised for its anticancer properties. We previously discovered that the C. nutans extract had the most potent inhibitory effect on MCF7 breast cancer cell and significantly induced apoptosis. However, there is a scarcity of studies demonstrating the molecular interactions of C. nutans-derived chemical compounds associated with apoptosis-related proteins. Therefore, the objective of this study was to determine the potential chemical compounds found in the C. nutans extract and examine their interactions with the targeted apoptotic proteins using molecular docking and molecular dynamic simulations. To address this objective, the compounds found in the SF2 extract of C. nutans were analysed using Gas Chromatography-Mass Spectrometry (GC-MS). The molecular interaction of the compounds with the targeted apoptotic proteins were determined using molecular docking and molecular dynamic simulations. GC-MS analysis revealed a total of 32 compounds in the SF2 extract. Molecular docking analysis showed that compound β-amyrenol had the highest binding affinity for MDM2-P53 (-7.26 kcal/mol), BCL2 (-11.14 kcal/mol), MCL1-BAX (-6.42 kcal/mol), MCL1-BID (-6.91 kcal/mol), and caspase-9 (-12.54 kcal/mol), whereas campesterol had the highest binding affinity for caspase-8 (-10.11 kcal/mol) and caspase-3 (-10.14 kcal/mol). These selected compounds were subjected to molecular dynamic simulation at 310 K for 100 ns. The results showed that the selected protein-ligand conformation complexes were stable, compact, and did not alter much when compared to the protein references. The findings indicate that β-amyrenol and campesterol are potentially significant compounds that might provide insight into the molecular interactions of the compounds with the apoptosis-related proteins.Communicated by Ramaswamy H. Sarma.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  3. Fulltext Brain proteomics links oxidative stress with metabolic and cellular stress response proteins in behavioural alteration of Alzheimer's disease model rats
    Rahman MA, Hossain S, Abdullah N, Aminudin N
    AIMS Neurosci, 2019;6(4):299-315.
    PMID: 32341985 DOI: 10.3934/Neuroscience.2019.4.299
    Alzheimer's disease (AD) impairs memory and learning related behavioural performances of the affected person. Compared with the controls, memory and learning related behavioural performances of the AD model rats followed by hippocampal proteomics had been observed in the present study. In the eight armed radial maze, altered performance of the AD rats had been observed. Using liquid chromatography coupled tandem mass spectrometry (LC-MS/MS), 822 proteins had been identified with protein threshold at 95.0%, minimum peptide of 2 and peptide threshold at 0.1% FDR. Among them, 329 proteins were differentially expressed with statistical significance (P < 0.05). Among the significantly regulated (P < 0.05) 329 proteins, 289 met the criteria of fold change (LogFC of 1.5) cut off value. Number of proteins linked with AD, oxidative stress (OS) and hypercholesterolemia was 59, 20 and 12, respectively. Number of commonly expressed proteins was 361. The highest amount of proteins differentially expressed in the AD rats were those involved in metabolic processes followed by those linked with OS. Most notable was the perturbed state of the cholesterol metabolizing proteins in the AD group. Current findings suggest that proteins associated with oxidative stress, glucose and cholesterol metabolism and cellular stress response are among the mostly affected proteins in AD subjects. Thus, novel therapeutic approaches targeting these proteins could be strategized to withstand the ever increasing global AD burden.
    Matched MeSH terms: Tandem Mass Spectrometry
  4. Label-free Quantitative Proteomic Analysis of Ascorbic Acid-induced Differentially Expressed Osteoblast-related Proteins in Dental Pulp Stem Cells from Deciduous and Permanent Teeth
    Zainol Abidin IZ, Manogaran T, Abdul Wahab RM, Karsani SA, Yazid MD, Yazid F, et al.
    Curr Stem Cell Res Ther, 2023;18(3):417-428.
    PMID: 35762553 DOI: 10.2174/1574888X17666220627145424
    BACKGROUND: Proteomic is capable of elucidating complex biological systems through protein expression, function, and interaction under a particular condition.

    OBJECTIVE: This study aimed to determine the potential of ascorbic acid alone in inducing differentially expressed osteoblast-related proteins in dental stem cells via the liquid chromatography-mass spectrometry/ mass spectrometry (LC-MS/MS) approach.

    METHODS: The cells were isolated from deciduous (SHED) and permanent teeth (DPSC) and induced with 10 μg/mL of ascorbic acid. Bone mineralisation and osteoblast gene expression were determined using von Kossa staining and reverse transcriptase-polymerase chain reaction. The label-free protein samples were harvested on days 7 and 21, followed by protein identification and quantification using LC-MS/MS. Based on the similar protein expressed throughout treatment and controls for SHED and DPSC, overall biological processes followed by osteoblast-related protein abundance were determined using the PANTHER database. STRING database was performed to determine differentially expressed proteins as candidates for SHED and DPSC during osteoblast development.

    RESULTS: Both cells indicated brownish mineral stain and expression of osteoblast-related genes on day 21. Overall, a total of 700 proteins were similar among all treatments on days 7 and 21, with 482 proteins appearing in the PANTHER database. Osteoblast-related protein abundance indicated 31 and 14 proteins related to SHED and DPSC, respectively. Further analysis by the STRING database identified only 22 and 11 proteins from the respective group. Differential expressed analysis of similar proteins from these two groups revealed ACTN4 and ACTN1 as proteins involved in both SHED and DPSC. In addition, three (PSMD11/RPN11, PLS3, and CLIC1) and one (SYNCRIP) protein were differentially expressed specifically for SHED and DPSC, respectively.

    CONCLUSION: Proteome differential expression showed that ascorbic acid alone could induce osteoblastrelated proteins in SHED and DPSC and generate specific differentially expressed protein markers.

    Matched MeSH terms: Tandem Mass Spectrometry
  5. Fulltext Crocodylus porosus Gut Bacteria: A Possible Source of Novel Metabolites
    Khan NA, Soopramanien M, Maciver SK, Anuar TS, Sagathevan K, Siddiqui R
    Molecules, 2021 Aug 18;26(16).
    PMID: 34443585 DOI: 10.3390/molecules26164999
    Crocodiles are remarkable animals that have the ability to endure extremely harsh conditions and can survive up to a 100 years while being exposed to noxious agents that are detrimental to Homo sapiens. Besides their immunity, we postulate that the microbial gut flora of crocodiles may produce substances with protective effects. In this study, we isolated and characterized selected bacteria colonizing the gastrointestinal tract of Crocodylusporosus and demonstrated their inhibitory effects against three different cancerous cell lineages. Using liquid chromatography-mass spectrometry, several molecules were identified. For the first time, we report partial analyses of crocodile's gut bacterial molecules.
    Matched MeSH terms: Mass Spectrometry
  6. Fulltext Upregulation of Brain's Calcium Binding Proteins in Mitragynine Dependence: A Potential Cellular Mechanism to Addiction
    Basheer M, Hassan Z, Gam LH
    Int J Med Sci, 2023;20(1):102-113.
    PMID: 36619231 DOI: 10.7150/ijms.78861
    Background: Mitragyna speciosa Korth or Kratom is widely used traditionally for its medicinal values. The major alkaloid content of kratom leaves is mitragynine, which binds to opioid receptors to give opioid-like effects. This study aimed to analyse the brain proteome of animals that displayed addictive behaviors. Design and Methods: Six groups (n=6-8) of rats made up of negative control, positive control using morphine (10 mg/kg), and treatment groups at low (1mg/kg) and high doses of mitragynine (30 mg/kg) for 1 and 4 days. The rats' behaviors were evaluated and subsequently the rats' brains were harvested for proteomic analysis that was performed by using 2D gel electrophoresis and LC/MS/MS. Results: The rats developed physical dependence only on day 4 following morphine and mitragynine (1 and 30mg/kg) treatments. Among the proteins that were up-regulated in treatment groups were four calcium-binding proteins, namely calretinin, F-actin, annexin A3 and beta-centractin. Conclusions: Upregulation of calretinin acted as low Ca2+ buffering upon the blockage of Ca2+ ion channel by mitragynine in the brain, which subsequently caused a reduction of GABA released and inversely increased the dopamine secretions that contributed to dependence indicators.
    Matched MeSH terms: Tandem Mass Spectrometry
  7. Identification of tropomyosin as major allergen of white squid (Loligo edulis) by two-dimensional immunoblotting and mass spectrometry
    Yadzir ZH, Misnan R, Murad S
    Southeast Asian J Trop Med Public Health, 2012 Jan;43(1):185-91.
    PMID: 23082569
    IgE-mediated allergic reaction to squid is one of the most frequent molluscan shellfish allergies. Previously, we have detected a 36 kDa protein as the major allergen of Loligo edulis (white squid) by immunoblotting using sera from patients with squid allergy. The aim of this present study was to further identify this major allergen using a proteomics approach. The major allergen was identified by a combination of two-dimensional electrophoresis (2-DE), immunoblotting, mass spectrometry and bioinformatics tools. The 2-DE gel fractionated the cooked white squid proteins to more than 50 different protein spots between 10 to 38 kDa and isoelectric point (pI) from 3.0 to 10.0. A highly reactive protein spot of a molecular mass of 36 kDa and pI of 4.55 was observed in all of the patients' serum samples tested. Mass spectrometry analysis led to identification of this allergen as tropomyosin. This finding can contribute to advancement in component-based diagnosis, management of squid allergic patients, to the development of immunotherapy and to the standardization of allergenic test products as tools in molecular allergology.
    Matched MeSH terms: Mass Spectrometry
  8. Fulltext Protein Profiling of Aedes aegypti Treated with Streptomyces sp. KSF103 Ethyl Acetate Extract Reveals Potential Insecticidal Targets and Metabolic Pathways
    Tan KS, Azman AS, Hassandarvish P, Amelia-Yap ZH, Tan TK, Low VL
    Int J Mol Sci, 2023 Aug 03;24(15).
    PMID: 37569772 DOI: 10.3390/ijms241512398
    The insecticidal activity of Streptomyces sp. KSF103 ethyl acetate (EA) extract against mosquitoes is known; however, the underlying mechanism behind this activity remains elusive. In this study, liquid chromatography with tandem mass spectrometry (LC-MS/MS) was employed to investigate changes in the protein profile of Aedes aegypti larvae and adults treated with lethal concentrations of 50 (LC50) EA extract. By comparing the treated and untreated mosquitoes, this study aimed to identify proteins or pathways that exhibit alterations, potentially serving as targets for future insecticide development. Treatment with a lethal concentration of EA extract upregulated 15 proteins in larvae, while in adults, 16 proteins were upregulated, and two proteins were downregulated. These proteins were associated with metabolism, protein regulation/degradation, energy production, cellular organization and structure, enzyme activity, and catalysis, as well as calcium ion transport and homeostasis. Notably, ATP synthase, fructose-bisphosphate aldolase (FBA), and ATP citrate synthase were significantly expressed in both groups. Gene ontology analysis indicated a focus on energy metabolic processes. Molecular docking revealed a strong interaction between dodemorph, selagine (compounds from the EA extract), and FBA, suggesting FBA as a potential protein target for insecticide development. Further studies such as Western blot and transcriptomic analyses are warranted to validate the findings.
    Matched MeSH terms: Tandem Mass Spectrometry
  9. Fulltext Contemporary Approaches to the Discovery and Development of Broad-Spectrum Natural Product Prototypes for the Control of Coronaviruses
    Hanna GS, Choo YM, Harbit R, Paeth H, Wilde S, Mackle J, et al.
    J Nat Prod, 2021 Nov 26;84(11):3001-3007.
    PMID: 34677966 DOI: 10.1021/acs.jnatprod.1c00625
    The pressing need for SARS-CoV-2 controls has led to a reassessment of strategies to identify and develop natural product inhibitors of zoonotic, highly virulent, and rapidly emerging viruses. This review article addresses how contemporary approaches involving computational chemistry, natural product (NP) and protein databases, and mass spectrometry (MS) derived target-ligand interaction analysis can be utilized to expedite the interrogation of NP structures while minimizing the time and expense of extraction, purification, and screening in BioSafety Laboratories (BSL)3 laboratories. The unparalleled structural diversity and complexity of NPs is an extraordinary resource for the discovery and development of broad-spectrum inhibitors of viral genera, including Betacoronavirus, which contains MERS, SARS, SARS-CoV-2, and the common cold. There are two key technological advances that have created unique opportunities for the identification of NP prototypes with greater efficiency: (1) the application of structural databases for NPs and target proteins and (2) the application of modern MS techniques to assess protein-ligand interactions directly from NP extracts. These approaches, developed over years, now allow for the identification and isolation of unique antiviral ligands without the immediate need for BSL3 facilities. Overall, the goal is to improve the success rate of NP-based screening by focusing resources on source materials with a higher likelihood of success, while simultaneously providing opportunities for the discovery of novel ligands to selectively target proteins involved in viral infection.
    Matched MeSH terms: Mass Spectrometry
  10. In-vitro anti-inflammatory activity, free radical (DPPH) scavenging, and ferric reducing ability (FRAP) of Sargassum cristaefolium lipid-soluble fraction and putative identification of bioactive compounds using UHPLC-ESI-ORBITRAP-MS/MS
    Saraswati, Giriwono PE, Iskandriati D, Tan CP, Andarwulan N
    Food Res Int, 2020 Nov;137:109702.
    PMID: 33233276 DOI: 10.1016/j.foodres.2020.109702
    Sargassum brown seaweed is well-known to contain several bioactive compounds which exhibit various biological activities, including anti-inflammatory and antioxidant activity. Lipophilic extracts and fractions of Sargassum were reported to possess promising anti-inflammatory activity. This study, therefore, aims to evaluate the anti-inflammatory and antioxidant activity of Sargassum cristaefolium crude lipid extract and its fractions. The brown seaweed was obtained from Awur Bay, Jepara - Indonesia. Crude lipid fractionation was performed using normal phase column chromatography, and three different fractions (dichloromethane, acetone, methanol) were produced. The results showed that treatment of acetone fraction exerted strongest nitric oxide inhibition in lipopolysaccharide-induced RAW 264.7 cells, both in pre-incubated and co-incubated cell culture models. This outcome was in accordance with its 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and ferric reducing antioxidant power (FRAP). Metabolite profiling of lipid fractions was performed by ultra-high-performance liquid chromatography electrospray ionization orbitrap tandem mass spectrometry, while the orthogonal projection to latent structures analysis was conducted to determine some features with significant correlation to the bioactivity. There were 14 feature candidates considered from both positive and negative ionization mode datasets. Seven out of them were putatively identified as pheophytin a (1), all-trans fucoxanthin (2), 132-hydroxy-pheophytin a (3), pheophorbide a (4), 1-hexadecanoyl-2-(9Z-octadecenoyl)-3-O-β-D-galactosyl-sn-glycerol (6), 1-(5Z,8Z,11Z,14Z,17Z-eicosapentaenoyl)-2-(9Z,12Z,15Z-octadecatrienoyl)-3-O-β-D-galactosyl-sn-glycerol (10), and 1-(9Z,12Z,15Z-octadecatrienoyl)-2-(6Z,9Z,12Z,15Z-octadecatetraenoyl)-3-O-β-D-galactosyl-sn glycerol (12).
    Matched MeSH terms: Tandem Mass Spectrometry
  11. Leaching of bisphenol A from new and old babies' bottles, and new babies' feeding teats
    Tan BL, Mustafa AM
    Asia Pac J Public Health, 2003;15(2):118-23.
    PMID: 15038686
    Bisphenol A is the monomer used in the manufacture of polycarbonate. Bisphenol A is also known to mimic the female hormone estrogen. In this study, the possibility of the leaching of bisphenol A from polycarbonate babies' bottles and feeding teats was investigated. Bisphenol A was extracted from water samples exposed to the bottles and teats using liquid-liquid extraction. Bisphenol A was analysed by gas chromatograph-mass spectrometer with quadrapole detector in selected ion monitoring mode. Mean leaching of bisphenol A from 100 used babies' bottles when filled with water at 25 degrees C and 80 degrees C were 0.71 +/- 1.65 ng/cm2 (mean +/- standard deviation) and 3.37 +/- 5.68 ng/cm2 respectively. Mean leaching of bisphenol A from 30 new babies' bottles when filled with water at 25 degrees C and 80 degrees C were 0.03 +/- 0.02 ng/cm2 and 0.18 degrees 0.30 ng/cm2 respectively. Bisphenol A was observed to have leached from babies' feeding teats into 37 degrees C water ranged from non-detectable to 22.86 ng/g. The technique employed in this study is fast, reliable and economical.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  12. Proteomics technology - a powerful tool for the biomedical scientists
    Noordin R, Othman N
    Malays J Med Sci, 2013 Mar;20(2):1-2.
    PMID: 23983570
    "Proteomics" refers to the systematic analysis of proteins. It complements other "omics" technologies such as genomics and transcriptomics in elucidating the identity of proteins of an organism, and understanding their functions. Proteomics is used in many areas of research such as discovery of markers for diagnosis and vaccine candidates, understanding pathogenic mechanisms, in the study of expression patterns at different time points and in response to different stimuli, and in elucidating functional protein networks. Proteomics analysis involves sample preparation, protein separation, and protein identification. The 'heart' of current proteomics is mass-spectrometry, with LC-MS/MS and MALDI-TOF/TOF being commonly used equipment. However, the high costs of the equipment, software, databases, and the need for skilled personnel limit the wide utilization of this technology in the less developed countries. Therefore, there need to be sharing of facilities, better networking and collaborations among our scientists and laboratories to take advantage of this powerful technology.
    Matched MeSH terms: Tandem Mass Spectrometry
  13. Fulltext Genome-based proteomic analysis of Lignosus rhinocerotis (Cooke) Ryvarden sclerotium
    Yap HY, Fung SY, Ng ST, Tan CS, Tan NH
    Int J Med Sci, 2015;12(1):23-31.
    PMID: 25552915 DOI: 10.7150/ijms.10019
    Lignosus rhinocerotis (Cooke) Ryvarden (Polyporales, Basidiomycota), also known as the tiger milk mushroom, has received much interest in recent years owing to its wide-range ethnobotanical uses and the recent success in its domestication. The sclerotium is the part with medicinal value. Using two-dimensional gel electrophoresis coupled with mass spectrometry analysis, a total of 16 non-redundant, major proteins were identified with high confidence level in L. rhinocerotis sclerotium based on its genome as custom mapping database. Some of these proteins, such as the putative lectins, immunomodulatory proteins, superoxide dismutase, and aegerolysin may have pharmaceutical potential; while others are involved in nutrient mobilization and the protective antioxidant mechanism in the sclerotium. The findings from this study provide a molecular basis for future research on potential pharmacologically active proteins of L. rhinocerotis.
    Matched MeSH terms: Mass Spectrometry/methods
  14. Fulltext HMG-CoA reductase inhibitory activity and phytocomponent investigation of Basella alba leaf extract as a treatment for hypercholesterolemia
    Baskaran G, Salvamani S, Ahmad SA, Shaharuddin NA, Pattiram PD, Shukor MY
    Drug Des Devel Ther, 2015;9:509-17.
    PMID: 25609924 DOI: 10.2147/DDDT.S75056
    The enzyme 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase is the key enzyme of the mevalonate pathway that produces cholesterol. Inhibition of HMG-CoA reductase reduces cholesterol biosynthesis in the liver. Synthetic drugs, statins, are commonly used for the treatment of hypercholesterolemia. Due to the side effects of statins, natural HMG-CoA reductase inhibitors of plant origin are needed. In this study, 25 medicinal plant methanol extracts were screened for anti-HMG-CoA reductase activity. Basella alba leaf extract showed the highest inhibitory effect at about 74%. Thus, B. alba was examined in order to investigate its phytochemical components. Gas chromatography with tandem mass spectrometry and reversed phase high-performance liquid chromatography analysis revealed the presence of phenol 2,6-bis(1,1-dimethylethyl), 1-heptatriacotanol, oleic acid, eicosyl ester, naringin, apigenin, luteolin, ascorbic acid, and α-tocopherol, which have been reported to possess antihypercholesterolemic effects. Further investigation of in vivo models should be performed in order to confirm its potential as an alternative treatment for hypercholesterolemia and related cardiovascular diseases.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry; Tandem Mass Spectrometry
  15. Simultaneous quantification of sildenafil and N-desmethyl sildenafil in human plasma by UFLC coupled with ESI-MS/MS and pharmacokinetic and bioequivalence studies in Malay population
    Liew KB, Loh GO, Tan YT, Peh KK
    Biomed Chromatogr, 2015 Jun;29(6):953-60.
    PMID: 25400284 DOI: 10.1002/bmc.3378
    A simple, rapid, specific and reliable UFLC coupled with ESI-MSMS assay method to simultaneously quantify sildenafil and N-desmethyl sildenafil, with loperamide as internal standard, was developed. Chromatographic separation was performed on a Thermo Scientific Accucore C18 column with an isocratic mobile phase composed of 0.1% v/v formic acid in purified water-methanol (20:80, v/v), at a flow rate of 0.3 mL/min. Sildenafil, N-desmethyl sildenafil and loperamide were detected with proton adducts at m/z 475.4 > 58.2, 461.3 > 85.2 and 477.0 > 266.1 in multiple reaction monitoring positive mode, respectively. Both analytes and internal standard were extracted by diethyl ether. The method was validated over a linear concentration range of 10-800 ng/mL for sildenafil and 10-600 ng/mL for N-desmethyl sildenafil with correlation coefficient (r(2) ) ≥0.9976 for sildenafil and (r(2) ) ≥0.9992 for N-desmethyl sildenafil. The method was precise, accurate and stable. The proposed method was applied to study the bioequivalence between a 100 mg dose of two pharmaceutical products: Viagra (original) and Edyfil (generic) products. AUC0-t , Cmax and Tmax were 2285.79 ng h/mL, 726.10 ng/mL and 0.94 h for Viagra and 2363.25 ng h/mL, 713.91 ng/mL and 0.83 hour for Edyfil. The 90% confidence interval of these parameters of this study fall within the regulatory range of 80-125%, hence they are considered as bioequivalent.
    Matched MeSH terms: Tandem Mass Spectrometry/methods*
  16. Assessment of gas chromatography time-of-flight accurate mass spectrometry for identification of volatile and semi-volatile compounds in honey
    Moniruzzaman M, Rodríguez I, Ramil M, Cela R, Sulaiman SA, Gan SH
    Talanta, 2014 Nov;129:505-15.
    PMID: 25127626 DOI: 10.1016/j.talanta.2014.06.019
    The performance of gas chromatography (GC) combined with a hybrid quadrupole time-of-flight (QTOF) mass spectrometry (MS) system for the determination of volatile and semi-volatile compounds in honey samples is evaluated. After headspace (HS) solid-phase microextraction (SPME) of samples, the accurate mass capabilities of the above system were evaluated for compounds identification. Accurate scan electron impact (EI) MS spectra allowed discriminating compounds displaying the same nominal masses, but having different empirical formulae. Moreover, the use of a mass window with a width of 0.005 Da provided highly specific chromatograms for selected ions, avoiding the contribution of interferences to their peak areas. Additional information derived from positive chemical ionization (PCI) MS spectra and ion product scan MS/MS spectra permitted confirming the identity of novel compounds. The above possibilities are illustrated with examples of honey aroma compounds, belonging to different chemical classes and containing different elements in their molecules. Examples of compounds whose structures could not be described are also provided. Overall, 84 compounds, from a total of 89 species, could be identified in 19 honey samples from 3 different geographic areas in the world. The suitability of responses measured for selected ions, corresponding to above species, for authentication purposes is assessed through principal components analysis.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry/methods*
  17. GC-MS-based metabolite profiling of Cosmos caudatus leaves possessing alpha-glucosidase inhibitory activity
    Javadi N, Abas F, Abd Hamid A, Simoh S, Shaari K, Ismail IS, et al.
    J Food Sci, 2014 Jun;79(6):C1130-6.
    PMID: 24888400 DOI: 10.1111/1750-3841.12491
    Cosmos caudatus, which is known as "Ulam Raja," is an herbal plant used in Malaysia to enhance vitality. This study focused on the evaluation of the α-glucosidase inhibitory activity of different ethanolic extracts of C. caudatus. Six series of samples extracted with water, 20%, 40%, 60%, 80%, and 100% ethanol (EtOH) were employed. Gas chromatography-mass spectrometry (GC-MS) and orthogonal partial least-squares (OPLS) analysis was used to correlate bioactivity of different extracts to different metabolite profiles of C. caudatus. The obtained OPLS scores indicated a distinct and remarkable separation into 6 clusters, which were indicative of the 6 different ethanol concentrations. GC-MS can be integrated with multivariate data analysis to identify compounds that inhibit α-glucosidase activity. In addition, catechin, α-linolenic acid, α-D-glucopyranoside, and vitamin E compounds were identified and indicate the potential α-glucosidase inhibitory activity of this herb.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry/methods
  18. Reduction of hexavalent chromium using Aerva lanata L.: elucidation of reduction mechanism and identification of active principles
    Poonkuzhali K, Rajeswari V, Saravanakumar T, Viswanathamurthi P, Park SM, Govarthanan M, et al.
    J Hazard Mater, 2014 May 15;272:89-95.
    PMID: 24681590 DOI: 10.1016/j.jhazmat.2014.03.001
    The effluent discharge treatment for controlling the environment from non biodegradable metal contaminants using plant extract is an efficient technique. The reduction of hexavalent chromium by abundantly available weed, Aerva lanata L. was investigated using batch equilibrium technique. The variables studied were Cr(VI) concentration, Aerva lanata L. dose, contact time, pH, temperature and agitation speed. Cyclic voltammetry and ICP-MS analysis confirmed the reduction of Cr(VI) to Cr(III). Electrochemical analysis proved that, the chromium has not been degraded and the valency of the chromium has only been changed. ICP-MS analysis shows that 100ng/L of hexavalent chromium was reduced to 97.01ng/L trivalent chromium. These results suggest that components present in the Aerva lanata L. are responsible for the reduction of Cr(VI) to Cr(III). The prime components ferulic acid, kaempherol and β-carboline present in the Aerva lanata L. may be responsible for the reduction of Cr(VI) as evident from LC-MS analysis.
    Matched MeSH terms: Mass Spectrometry/methods
  19. Prioritization of natural extracts by LC-MS-PCA for the identification of new photosensitizers for photodynamic therapy
    Samat N, Tan PJ, Shaari K, Abas F, Lee HB
    Anal Chem, 2014 Feb 4;86(3):1324-31.
    PMID: 24405504 DOI: 10.1021/ac403709a
    Photodynamic therapy (PDT) is an alternative treatment for cancer that involves administration of a photosensitive drug or photosensitizer that localizes at the tumor tissue followed by in situ excitation at an appropriate wavelength of light. Tumour tissues are then killed by cytotoxic reactive oxygen species generated by the photosensitizer. Targeted excitation and photokilling of affected tissues is achieved through focal light irradiation, thereby minimizing systemic side effects to the normal healthy tissues. Currently, there are only a small number of photosensitizers that are in the clinic and many of these share the same structural core based on cyclic tetrapyrroles. This paper describes how metabolic tools are utilized to prioritize natural extracts to search for structurally new photosensitizers from Malaysian biodiversity. As proof of concept, we analyzed 278 photocytotoxic extracts using a hyphenated technique of liquid chromatography-mass spectrometry coupled with principal component analysis (LC-MS-PCA) and prioritized 27 extracts that potentially contained new photosensitizers for chemical dereplication using an in-house UPLC-PDA-MS-Photocytotoxic assay platform. This led to the identification of 2 new photosensitizers with cyclic tetrapyrrolic structures, thereby demonstrating the feasibility of the metabolic approach.
    Matched MeSH terms: Mass Spectrometry*
  20. Headspace solid-phase microextraction gas chromatography-mass spectrometry determination of volatile compounds in different varieties of African star apple fruit (Chrysophillum albidum)
    Lasekan O, Khatib A, Juhari H, Patiram P, Lasekan S
    Food Chem, 2013 Dec 1;141(3):2089-97.
    PMID: 23870932 DOI: 10.1016/j.foodchem.2013.05.081
    The volatile compounds in four selected African star apple fruit (Chrysophyllum albidum) varieties were isolated and identified using the headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). A total of 59 compounds were identified. Application of the aroma extract dilution analysis (AEDA) to the aroma distillates from the fruits revealed 45 odour-active compounds in the flavour dilution (FD) factor range of 4-128. Among them, the highest odour activities (FD factors) were determined for methylhexanoate, acetophenone and ethyl dodecanoate. Moreover, aroma lipophilicity appears to reflect molecular conformation. Further analysis of the similarities and differences between the fruit varieties in terms of the key odourants by the application of PLS-DA and PLS-regression coefficient showed strong positive correlation between the very sweet/sweet varieties and 10 key odourants. The odourants included ethyl acetate, acetyl methyl carbinol, methylhexanoate, sabinene, p-cymene, methylbenzoate, ethylbenzoate, geraniol, cis-α-bergomotene, acetophenone, and ethyl dodecanoate.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry/methods*
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links