Displaying publications 241 - 260 of 951 in total

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  1. HPLC-MS/MS method for bioavailability study of bruceines D & E in rat plasma
    Man F, Choo CY
    J Chromatogr B Analyt Technol Biomed Life Sci, 2017 Sep 15;1063:183-188.
    PMID: 28869873 DOI: 10.1016/j.jchromb.2017.08.037
    Bruceines D and E are quassinoids from seeds of Brucea javanica (L.) Merr. exhibiting hypoglycemia effect. The crude drug is used as a traditional medicine by diabetes patients. The aim of this study is to understand the bioavailability and pharmacokinetics of both the bruceines D & E. A rapid and sensitive HPLC-MS/MS method was developed and validated for the quantification of both quassinoids, bruceines D & E in rat plasma. Both the bruceines D & E were separated with the Zorbax SBC-18 column with gradient elution and mobile phase system of acetonitrile and deionized water with 0.1% formic acid at a flow rate of 0.5mL/min. Analytes were detected in multiple reaction monitoring (MRM) mode with electrospray positive ionization. The quassinoids, namely bruceines D & E were detected with transitions of m/z 411.2→393.2 and m/z 395.2→377.2, respectively. Another quassinoid, eurycomanone was used as the internal standard with transition of m/z 409.2→391.2. The method was validated and conformed to the regulatory requirements. The validated method was applied to pharmacokinetic and bioavailability studies in rats. The pharmacokinetic study indicated both bruceine D and E were rapidly absorbed into the circulation system and reached its peak concentration at 0.54±0.34h and 0.66±0.30h, respectively. Bruceine E was eliminated slower than Bruceine D with t1/2 value almost increased two-fold compared to Bruceine D. In conclusion, a rapid, selective and sensitive HPLC-MS/MS method was developed for the simultaneous determination of both the bruceines D and E in rat plasma. Both bruceines D and E displayed poor oral bioavailability.
    Matched MeSH terms: Tandem Mass Spectrometry/methods*
  2. Simple, rapid and sensitive assay method for simultaneous quantification of urinary nicotine and cotinine using gas chromatography-mass spectrometry
    Man CN, Gam LH, Ismail S, Lajis R, Awang R
    J Chromatogr B Analyt Technol Biomed Life Sci, 2006 Dec 5;844(2):322-7.
    PMID: 16908224
    Nicotine is a major addictive compound in cigarette. Its smoke is rapidly and extensively metabolized to several metabolites in human. Cotinine as a major metabolite of nicotine is commonly used as a biomarker to determine active and passive smokers. Cotinine has a longer half-life ( approximately 20 h) compared to nicotine ( approximately 2h). A simple, sensitive, rapid and high throughput GC-MS method was developed for simultaneous quantification of urinary nicotine and cotinine in passive and active smokers. In the sample preparation method, the analytes and internal standard were first basified and followed by liquid-liquid extraction. Upon completion, anhydrous sodium sulphate was added to the solvent mixture to trap moistures. The clear extract obtained was directly injected into GC-MS, operating under selective ion monitoring (SIM) mode. Calibration curves in the range of 0.5-5000 ng/mL of the analytes in urine matrix were established with linear correlation coefficients (r(2)) greater than 0.997. The limit of detection for both nicotine and cotinine were 0.20 ng/mL. The mean recoveries for nicotine and cotinine were 93.0 and 100.4%, respectively. The within- and between-assay accuracies were between 2.1 and 7.9% for nicotine and between 0.7 and 11.1% for cotinine. Within- and between-assay precisions of 3.3-9.5% for nicotine and 3.4-9.8% for cotinine were also achieved. The method can be used in routine assessment and monitoring of active smoking and exposure to environmental tobacco smoke. The applicability of the assay was demonstrated in a small-scale comparison study between smokers and non-smokers.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry/methods*
  3. Determination of hair nicotine by gas chromatography-mass spectrometry
    Man CN, Ismail S, Harn GL, Lajis R, Awang R
    J Chromatogr B Analyt Technol Biomed Life Sci, 2009 Jan 15;877(3):339-42.
    PMID: 19109080 DOI: 10.1016/j.jchromb.2008.12.014
    Hair nicotine is a known biomarker for monitoring long-term environmental tobacco smoke (ETS) exposure and smoking status. In general, hair nicotine assay involves alkaline digestion, extraction and instrumental analysis. The gas chromatography-mass spectrometry (GC-MS) assay currently developed has shown to be of high throughput with average approximately 100 hair samples being extracted and analyzed per day. This was achieved through simplified extraction procedure and shortened GC analysis time. The extraction was improved by using small volume (0.4 mL) of organic solvent that does not require further evaporation and salting steps prior to GC-MS analysis. Furthermore, the amount of hair utilized in the extraction was very little (5 mg) while the sensitivity and selectivity of the assay is equal, if not better than other established methods. The linearity of the assay (r(2)>0.995), limit of quantitation (0.04 ng/mg hair), within- and between-assays accuracies and precisions (<11.4%) and mean recovery (92.6%) were within the acceptable range.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry*
  4. Chiral liquid chromatography-mass spectrometry (LC-MS/MS) method development for the detection of salbutamol in urine samples
    Chan SH, Lee W, Asmawi MZ, Tan SC
    J Chromatogr B Analyt Technol Biomed Life Sci, 2016 Jul 01;1025:83-91.
    PMID: 27232053 DOI: 10.1016/j.jchromb.2016.05.015
    A sequential solid-phase extraction (SPE) method was developed and validated using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) for the detection and quantification of salbutamol enantiomers in porcine urine. Porcine urine samples were hydrolysed with β-glucuronidase/arylsulfatase from Helix pomatia and then subjected to a double solid-phase extraction (SPE) first using the Abs-Elut Nexus SPE and then followed by the Bond Elut Phenylboronic Acid (PBA) SPE. The salbutamol enantiomers were separated using the Astec CHIROBIOTIC™ T HPLC column (3.0mm×100mm; 5μm) maintained at 15°C with a 15min isocratic run at a flow rate of 0.4mL/min. The mobile phase constituted of 5mM ammonium formate in methanol. Salbutamol and salbutamol-tert-butyl-d9 (internal standard, IS) was monitored and quantified with the multiple reaction monitoring (MRM) mode. The method showed good linearity for the range of 0.1-10ng/mL with limit of quantification at 0.3ng/mL. Analysis of the QC samples showed intra- and inter-assay precisions to be less than 5.04%, and recovery ranging from 83.82 to 102.33%.
    Matched MeSH terms: Tandem Mass Spectrometry/methods*
  5. LC-MS/MS profiling of the poisonous wild mushroom, Entoloma mastoideum, (Entolomataceae, Basidiomycota) in Sabah (Northern Borneo), Malaysia
    M H Subari IAA, Mutthumanickam G, Hj Jikal M, Shah MD, Tan JK, Tan YS, et al.
    Toxicon, 2024 Nov 28;251:108133.
    PMID: 39426425 DOI: 10.1016/j.toxicon.2024.108133
    In Malaysia, mushroom poisoning poses a significant public health concern, particularly as local communities frequently consume wild mushrooms without fully recognizing the potential dangers they present. Ingestion of wild mushrooms, which resemble edible species but contain deadly chemicals, is the main cause of poisoning risk. The genus Entoloma (Fr.) P. Kumm is dispersed worldwide, with over 1500 species recorded. Entoloma mastoideum, a poisonous mushroom, was recorded for the first time at Kota Marudu district, Sabah, Malaysia, where ten cases of mushroom poisoning outbreaks were recorded during the rainy season of October 2019. The morphological characters of the specimens were documented and their microscopic features were analyzed using compound microscope and scanning electron microscope. A phylogenetic tree was constructed using Maximum likelihood and Bayesian analysis. Chemical profiling of the poisonous mushroom specimen was done via liquid chromatograph mass spectrometry (LC-MS/MS) to identify toxic metabolites. The phylogenetic analysis showed that the Bornean E. mastoideum is closely related to the Chinese isolates (100% BS/1.0 PP). LC-MS/MS profiling detected a total of 162 metabolites that were classified into ten general groups, where several toxic compounds were detected amongst the aromatics, essential amino acids, and fatty acid derivatives. The toxic compounds identified in the mushroom extract, including amino acid derivatives such as 3,4,5,6-tetrahydroxyynorleucine, valpromide, and betaine, have been reported to cause neurotoxicity, cardiotoxicity, liver damage, and gastrointestinal harm. The presence of these toxic compounds underscores the need for caution when consuming wild mushrooms. Further research on poisonous Entoloma species is vital for developing accurate identification methods and understanding their toxic potential. This knowledge is essential for enhancing public awareness, preventing mushroom poisoning incidents and safeguarding public health.
    Matched MeSH terms: Tandem Mass Spectrometry*
  6. Gas Chromatography-Mass Spectrometry (GC-MS) Analysis of Scaphium Affine Seed Extract and Assessment of Its Anti-hemorrhoidal Efficacy
    Abbas SA, Khan A, Fatima M, Kalusalingam A, Kanakal MM, Inamdar SK, et al.
    Antiinflamm Antiallergy Agents Med Chem, 2024;23(2):118-128.
    PMID: 38357954 DOI: 10.2174/0118715230285370240131111539
    BACKGROUND: Seeds of plant Scaphium affine are traditionally used by the healers of "India" for the treatment of piles.

    OBJECTIVES: The primary objective of the study was to assess the anti-hemorrhoidal potential of the ethanolic seed extract of Scaphium affine.

    METHODS: After the soxhlet extraction method, the seed extract from Scaphium affine was first submitted to phytochemical standardization and then GC-MS analysis. Rats were given Croton oil and Jatropha oil to develop hemorrhoids, and Scaphium affine seed extract (ESA) was administered orally for 5 days and 3 days, respectively, at doses of 1000 and 500 mg/kg. The Rectoanal coefficient (RAC) was calculated as an inflammatory marker. The hemorrhoidal tissues were also subjected to cytokine profiling, biochemical estimation and histopathology.

    RESULTS: ESA demonstrated the presence of flavonoids, saponins, phytosterols, phenols, and tannins. GCMS analysis elucidated the presence of hexadecanoic acid 2 hydroxy -1,3 propane diyl ester,9 Octadecanoic acid ethyl ester, Cyclohexane 1,4 di methyl cis, Farnesol isomer,1, E-11, Z-13 octa decatriene, Stigmasterol, N-(5 ethyl -1,3,4-thiadiazol-yl) benzamide, N, N Dinitro 1,3,5,7 tetraza bicyclo 93,3,1) as major phytoconstituents. The results depicted more potent anti-hemorrhoidal activity of ESA at 1000 mg/kg, p.o., which was evident through a decrease in RAC. A significant decline in the levels of IL-1β, IL-6, and TNF-α expression was observed, along with the restoration of altered antioxidants and enzymes. Histopathological analysis confirmed the tissue recovery as it revealed minimal inflammation and decreased dilated blood vessels in treated animals.

    CONCLUSION: Based on the results it can be concluded that seeds of Scaphium affine showed significant anti-hemorrhoid agents which may be attributed to their anti-inflammatory and anti-oxidant potential due to the presence of certain phytoconstituents in it. The study also supports the traditional use of seeds of Scaphium affine for the first time in the treatment of hemorrhoids.

    Matched MeSH terms: Gas Chromatography-Mass Spectrometry*
  7. Unbiased Metabolomic and Chemometric profiles of three Sargassum polycystum extracts using GCMS and LCMS/MS: content analysis, correlation analysis and molecular docking
    Alallam B, Abdulameed HT, Lim V
    Food Chem, 2025 Apr 01;470:142666.
    PMID: 39755036 DOI: 10.1016/j.foodchem.2024.142666
    Sargassum polycystum (S. polycystum) is a brown macroalga with a high phytochemical content, making it a nutritious and bioactive food source. However, information on factors contributing to health benefits, like antioxidants and cytotoxicity, is less explored for Malaysian S. polycystum. In this study, three extracts of S. polycystum were characterized using a combination of analytical techniques. Despite similar carbohydrate content across all extracts, water extract exhibited the highest protein [21.90 ± 1.01 albumin equivalent (μg/mg)] and phenolic [7.73 ± 1.95 gallic acid equivalent (μg/mg)] contents. However, it displayed the lowest antioxidant and anticancer activities [half-maximal inhibitory concentration (IC50) of > 2000 μg/mL]. Interestingly, ethanolic extract demonstrated the strongest scavenging activity (IC50 of 397.90 ± 20.43 μg/mL) and selective anticancer activity against MCF7 breast cancer cells (IC50 of 338.63 ± 48.98 μg/mL). Untargeted metabolomic profiling confirmed the differences in the chemical composition of the extracts. Subsequently, correlation and docking analyses were used to identify the potential bioactive compounds within the extracts. The ethanolic extract is a rich source of these bioactive compounds with superior antioxidant and anticancer properties, highlighting the need for further research on its potential utility in the food industry.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry; Tandem Mass Spectrometry
  8. Fulltext Proteogenomic Gene Structure Validation in the Pineapple Genome
    Ariffin N, Newman DW, Nelson MG, O'cualain R, Hubbard SJ
    J Proteome Res, 2024 May 03;23(5):1583-1592.
    PMID: 38651221 DOI: 10.1021/acs.jproteome.3c00675
    MD2 pineapple (Ananas comosus) is the second most important tropical crop that preserves crassulacean acid metabolism (CAM), which has high water-use efficiency and is fast becoming the most consumed fresh fruit worldwide. Despite the significance of environmental efficiency and popularity, until very recently, its genome sequence has not been determined and a high-quality annotated proteome has not been available. Here, we have undertaken a pilot proteogenomic study, analyzing the proteome of MD2 pineapple leaves using liquid chromatography-mass spectrometry (LC-MS/MS), which validates 1781 predicted proteins in the annotated F153 (V3) genome. In addition, a further 603 peptide identifications are found that map exclusively to an independent MD2 transcriptome-derived database but are not found in the standard F153 (V3) annotated proteome. Peptide identifications derived from these MD2 transcripts are also cross-referenced to a more recent and complete MD2 genome annotation, resulting in 402 nonoverlapping peptides, which in turn support 30 high-quality gene candidates novel to both pineapple genomes. Many of the validated F153 (V3) genes are also supported by an independent proteomics data set collected for an ornamental pineapple variety. The contigs and peptides have been mapped to the current F153 genome build and are available as bed files to display a custom gene track on the Ensembl Plants region viewer. These analyses add to the knowledge of experimentally validated pineapple genes and demonstrate the utility of transcript-derived proteomics to discover both novel genes and genetic structure in a plant genome, adding value to its annotation.
    Matched MeSH terms: Tandem Mass Spectrometry*
  9. Fulltext Comparative study of the metal accumulation in Hysterothalycium reliquens (nematode) and Paraphilometroides nemipteri (nematode) as compared with their doubly infected host, Nemipterus peronii (Notched threadfin bream)
    Mazhar R, Shazili NA, Harrison FS
    Parasitol Res, 2014 Oct;113(10):3737-43.
    PMID: 25115732 DOI: 10.1007/s00436-014-4039-x
    In February 2013, forty-seven Notched threadfin bream, the Nemipterus peronii, were sampled from the eastern coastal waters of the South China Sea. The concentration of various elements, namely cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), strontium (Sr), manganese (Mn), selenium (Se), Lead (Pb), nickel (Ni), aluminum (Al), arsenic (As), iron (Fe), and Zinc (Zn) were analyzed in the liver, muscle, and kidney organs of the host, as well as in their parasites Hysterothalycium reliquens (nematode) and the Paraphilometroides nemipteri (nematode), using inductively coupled plasma mass spectrometry (ICP-MS). The former group of parasites showed highest accumulation capacity for Cr, Cu, Fe, Mn, Se, Ni, and Zn while the latter group had high accumulation potential of As, Hg, Cd, Al, Pb, and Sr. The divergence in heavy-metal accumulation profiles of both nematodes is linked with the specificity of microhabitats, cuticle morphology, and interspecific competition. The outcome of this study indicates that both parasite models can be used for biomonitoring of metal pollution in marine ecosystems.
    Matched MeSH terms: Mass Spectrometry/methods; Mass Spectrometry/veterinary
  10. Fulltext Investigation of Antioxidative and Anticancer Potentials of Streptomyces sp. MUM256 Isolated from Malaysia Mangrove Soil
    Tan LT, Ser HL, Yin WF, Chan KG, Lee LH, Goh BH
    Front Microbiol, 2015;6:1316.
    PMID: 26635777 DOI: 10.3389/fmicb.2015.01316
    A Streptomyces strain, MUM256 was isolated from Tanjung Lumpur mangrove soil in Malaysia. Characterization of the strain showed that it has properties consistent with those of the members of the genus Streptomyces. In order to explore the potential bioactivities, extract of the fermented broth culture of MUM256 was prepared with organic solvent extraction method. DPPH and SOD activity were utilized to examine the antioxidant capacity and the results have revealed the potency of MUM256 in superoxide anion scavenging activity in dose-dependent manner. The cytotoxicity of MUM256 extract was determined using cell viability assay against 8 different panels of human cancer cell lines. Among all the tested cancer cells, HCT116 was the most sensitive toward the extract treatment. At the highest concentration of tested extract, the result showed 2.3-, 2.0-, and 1.8-folds higher inhibitory effect against HCT116, HT29, and Caco-2 respectively when compared to normal cell line. This result has demonstrated that MUM256 extract was selectively cytotoxic toward colon cancer cell lines. In order to determine the constituents responsible for its bioactivities, the extract was then subjected to chemical analysis using GC-MS. The analysis resulted in the identification of chemical constituents including phenolic and pyrrolopyrazine compounds which may responsible for antioxidant and anticancer activities observed. Based on the findings of this study, the presence of bioactive constituents in MUM256 extract could be a potential source for the development of antioxidative and chemopreventive agents.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  11. Unantimycin A, a new neoantimycin analog isolated from a microbial metabolite fraction library
    Lim CL, Nogawa T, Okano A, Futamura Y, Kawatani M, Takahashi S, et al.
    J Antibiot (Tokyo), 2016 06;69(6):456-8.
    PMID: 26648115 DOI: 10.1038/ja.2015.124
    Matched MeSH terms: Mass Spectrometry
  12. Chemical compositions and antimicrobial activity of the essential oils of Piper abbreviatum, P. erecticaule and P. lanatum (Piperaceae)
    Wan Salleh WM, Ahmad F, Yen KH
    Nat Prod Commun, 2014 Dec;9(12):1795-8.
    PMID: 25632488
    The study was designed to examine the chemical composition and antimicrobial activities of essential oils extracted from the aerial parts of three Piper species: Piper abbreviatum, P. erecticaule and P. lanatum, all from Malaysia. GC and GC/MS analysis showed qualitative and quantitative differences between these oils. GC and GC-MS analysis of P. abbreviatum, P. erecticaule and P. lanatum oils resulted in the identification of 33, 35 and 39 components, representing 70.5%, 63.4% and 78.2% of the components, respectively. The major components of P. abbreviatum oil were spathulenol (11.2%), (E)-nerolidol (8.5%) and β-caryophyllene (7.8%), whereas P. erecticaule oil mainly contained β-caryophyllene (5.7%) and spathulenol (5.1%). Borneol (7.5%), β-caryophyllene (6.6%) and α-amorphene (5.6%) were the most abundant components in P. lanatum oil. Antimicrobial activity was carried out using disc diffusion and broth micro-dilution method against nine microorganisms. All of the essential oils displayed weak activity towards Gram-positive bacteria with MIC values in the range 250-500 μg/mL. P. erecticaule oil showed the best activity on Aspergillus niger (MIC 31.3 μg/mL), followed by P. lanatum oil (MIC 62.5 μg/mL). This study demonstrated that the essential oils have potential as antimicrobial agents and may be useful in the pharmaceutical and cosmetics industries.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  13. Antioxidant activity of Piper nigrum L. essential oil extracted by supercritical CO₂ extraction and hydro-distillation
    Bagheri H, Abdul Manap MY, Solati Z
    Talanta, 2014 Apr;121:220-8.
    PMID: 24607131 DOI: 10.1016/j.talanta.2014.01.007
    The aim of this study was to optimize the antioxidant activity of Piper nigrum L. essential oil extracted using the supercritical carbon dioxide (SC-CO₂) technique. Response surface methodology was applied using a three-factor central composite design to evaluate the effects of three independent extraction variables: pressure of 15-30 MPa, temperature of 40-50 °C and dynamic extraction time of 40-80 min. The DPPH radical scavenging method was used to evaluate the antioxidant activity of the extracts. The results showed that the best antioxidant activity was achieved at 30 MPa, 40 °C and 40 min. The extracts were analyzed by GC-FID and GC-MS. The main components extracted using SC-CO₂ extraction in optimum conditions were β-caryophyllene (25.38 ± 0.62%), limonene (15.64 ± 0.15%), sabinene (13.63 ± 0.21%), 3-carene (9.34 ± 0.04%), β-pinene (7.27 ± 0.05%), and α-pinene (4.25 ± 0.06%). The essential oil obtained through this technique was compared with the essential oil obtained using hydro-distillation. For the essential oil obtained by hydro-distillation, the most abundant compounds were β-caryophyllene (18.64 ± 0.84%), limonene (14.95 ± 0.13%), sabinene (13.19 ± 0.17%), 3-carene (8.56 ± 0.11%), β-pinene (9.71 ± 0.12%), and α-pinene (7.96 ± 0.14%). Radical scavenging activity of the extracts obtained by SC-CO₂ and hydro-distillation showed an EC₅₀ of 103.28 and 316.27 µg mL(-1) respectively.
    Matched MeSH terms: Mass Spectrometry
  14. Modeling of crude oil biodegradation using two phase partitioning bioreactor
    Fakhru'l-Razi A, Peyda M, Ab Karim Ghani WA, Abidin ZZ, Zakaria MP, Moeini H
    Biotechnol Prog, 2014 Jul-Aug;30(4):797-805.
    PMID: 24692323 DOI: 10.1002/btpr.1911
    In this work, crude oil biodegradation has been optimized in a solid-liquid two phase partitioning bioreactor (TPPB) by applying a response surface methodology based d-optimal design. Three key factors including phase ratio, substrate concentration in solid organic phase, and sodium chloride concentration in aqueous phase were taken as independent variables, while the efficiency of the biodegradation of absorbed crude oil on polymer beads was considered to be the dependent variable. Commercial thermoplastic polyurethane (Desmopan®) was used as the solid phase in the TPPB. The designed experiments were carried out batch wise using a mixed acclimatized bacterial consortium. Optimum combinations of key factors with a statistically significant cubic model were used to maximize biodegradation in the TPPB. The validity of the model was successfully verified by the good agreement between the model-predicted and experimental results. When applying the optimum parameters, gas chromatography-mass spectrometry showed a significant reduction in n-alkanes and low molecular weight polycyclic aromatic hydrocarbons. This consequently highlights the practical applicability of TPPB in crude oil biodegradation.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  15. Potential of a white-rot fungus Pleurotus eryngii F032 for degradation and transformation of fluorene
    Hadibarata T, Kristanti RA
    Fungal Biol, 2014 Feb;118(2):222-7.
    PMID: 24528643 DOI: 10.1016/j.funbio.2013.11.013
    The white-rot fungus Pleurotus eryngii F032 showed the capability to degrade a three fused-ring aromatic hydrocarbons fluorene. The elimination of fluorene through sorption was also investigated. Enzyme production is accompanied by an increase in biomass of P. eryngii F032 during degradation process. The fungus totally degraded fluorine within 23 d at 10-mg l(-1) solution. Fluorene degradation was affected with initial fluorene concentrations. The highest enzyme activity was shown by laccase in the 10-mg l(-1) culture after 30 d of incubation (1620 U l(-1)). Few activities of enzymes were observed in the fungal cell at the varying concentration of fluorene. Three metabolic were detected and separated in ethylacetate extract, after isolated by column chromatography. The metabolites, 9-fluorenone, phthalic acid, and benzoic acid were identified using UV-vis spectrophotometer and gas chromatography-mass spectrometry (GC-MS). The results show the presence of a complex mechanism for the regulation of fluorene-degrading enzymes.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  16. The effects of physical refining on the formation of 3-monochloropropane-1,2-diol esters in relation to palm oil minor components
    Zulkurnain M, Lai OM, Latip RA, Nehdi IA, Ling TC, Tan CP
    Food Chem, 2012 Nov 15;135(2):799-805.
    PMID: 22868161 DOI: 10.1016/j.foodchem.2012.04.144
    The formation of 3-monochloropropane-1,2-diol (3-MCPD) esters in refined palm oil during deodorisation is attributed to the intrinsic composition of crude palm oil. Utilising D-optimal design, the effects of the degumming and bleaching processes on the reduction in 3-MCPD ester formation in refined palm oil from poor-quality crude palm oil were studied relative to the palm oil minor components that are likely to be their precursors. Water degumming remarkably reduced 3-MCPD ester formation by up to 84%, from 9.79 mg/kg to 1.55 mg/kg. Bleaching with synthetic magnesium silicate caused a further 10% reduction, to 0.487 mg/kg. The reduction in 3-MCPD ester formation could be due to the removal of related precursors prior to the deodorisation step. The phosphorus content of bleached palm oil showed a significant correlation with 3-MCPD ester formation.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  17. Characterisation of calamansi (Citrus microcarpa). Part II: volatiles, physicochemical properties and non-volatiles in the juice
    Cheong MW, Zhu D, Sng J, Liu SQ, Zhou W, Curran P, et al.
    Food Chem, 2012 Sep 15;134(2):696-703.
    PMID: 23107680 DOI: 10.1016/j.foodchem.2012.02.139
    Calamansi juices from three countries (Malaysia, the Philippines and Vietnam) were characterised through measuring volatiles, physicochemical properties and non-volatiles (sugars, organic acids and phenolic acids). The volatile components of manually squeezed calamansi juices were extracted using dichloromethane and headspace solid-phase microextraction, and then analysed using gas chromatography-mass spectrometry/flame ionisation detector, respectively. A total of 60 volatile compounds were identified. The results indicated that the Vietnam calamansi juice contained the highest amount of volatiles. Two principal components obtained from principal component analysis (PCA) represented 89.65% of the cumulative total variations of the volatiles. Among the non-volatile components, these three calamansi juices could be, to some extent, differentiated according to fructose and glucose concentrations. Hence, this study of calamansi juices could lead to a better understanding of calamansi fruits.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  18. Fulltext Synthesis, characterization and fluorescent property evaluation of 1,3,5-triaryl-2-pyrazolines
    Hasan A, Abbas A, Akhtar MN
    Molecules, 2011 Sep 13;16(9):7789-802.
    PMID: 22143543 DOI: 10.3390/molecules16097789
    A series of 1,3,5-triaryl-2-pyrazolines was synthesized by dissolving the corresponding 4-alkoxychalcones in glacial acetic acid containing a few drops of concentrated hydrochloric acid. This step was followed by the addition of (3,4-dimethylphenyl) hydrazaine hydrochloride. Finally the target compounds were precipitated by pouring the reaction mixture onto crushed ice. The structures of the synthesized compounds were established by physicochemical and spectroscopic methods. The 1,3,5-triaryl-2-pyrazolines bearing homologous alkoxy groups were found to possess fluorescence properties in the blue region of the visible spectrum when irradiated with ultraviolet radiation. The fluorescent behavior of these compounds was studied by UV-Vis and emission spectroscopy, performed at room temperature.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  19. Speciation of heavy metals by modified BCR sequential extraction procedure in different depths of sediments from Sungai Buloh, Selangor, Malaysia
    Nemati K, Abu Bakar NK, Abas MR, Sobhanzadeh E
    J Hazard Mater, 2011 Aug 15;192(1):402-10.
    PMID: 21684080 DOI: 10.1016/j.jhazmat.2011.05.039
    The sequential extraction procedure proposed by the European Standard, Measurements and Testing (SM&T) program, formerly the Community Bureau of Reference (BCR), was applied for partitioning of heavy metals (HMs) in river sediments collected along the course of Sungai Buloh and the Straits of Malacca in Selangor, Malaysia. Eight elements (V, Pb, Cd, Cr, Co, Ni, Cu and Zn) from seven stations (S1-S7) and at different depths were analyzed using the modified BCR Sequential Extraction Procedure (SEP) in combination with ICP-MS to obtain the metal distribution patterns in this region. The results showed that heavy metal contaminations at S2 and S3 was more severe than at other sampling sites, especially for Zn, Cu, Ni and Pb. Nevertheless, the element concentrations from top to bottom layers decreased predominantly. The samples from the Straits of Malacca (S4-S7) the highest contamination factors obtained were for Co, Zn and Pb while the lowest were found for V and Cr, similar to Sungai Buloh sediments. The sediments showed a low risk for V, Cr, Cu and Pb with RAC values of less than 10%, but medium risk for Co, Zn (except S3), Cd at S1 and S2 and Ni at S1, S3 and S5. Zn at S3 and Cd at S3-S7 showed high risk to our sediment samples. There is not any element of very high risk conditions in the selected samples.
    Matched MeSH terms: Mass Spectrometry
  20. Fulltext Synthesis, characterization, acetylcholinesterase inhibition, molecular modeling and antioxidant activities of some novel Schiff bases derived from 1-(2-ketoiminoethyl)piperazines
    Salga SM, Ali HM, Abdullah MA, Abdelwahab SI, Wai LK, Buckle MJ, et al.
    Molecules, 2011 Nov 07;16(11):9316-30.
    PMID: 22064271 DOI: 10.3390/molecules16119316
    Some novel Schiff bases derived from 1-(2-ketoiminoethyl)piperazines were synthesized and characterized by mass spectroscopy, FTIR, UV-Visible, 1H and 13C-NMR. The compounds were tested for inhibitory activities on human acetylcholinesterase (hAChE), antioxidant activities, acute oral toxicity and further studied by molecular modeling techniques. The study identified the compound (DHP) to have the highest activity among the series in hAChE inhibition and DPPH assay while the compound LP revealed the highest activity in the FRAP assay. The hAChE inhibitory activity of DHP is comparable with that of propidium, a known AChE inhibitor. This high activity of DHP was checked by molecular modeling which showed that DHP could not be considered as a bivalent ligand due to its incapability to occupy the esteratic site (ES) region of the 3D crystal structure of hAChE. The antioxidant study unveiled varying results in 1,1-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. This indicates mechanistic variations of the compounds in the two assays. The potential therapeutic applications and safety of these compounds were suggested for use as human acetylcholinesterase inhibitors and antioxidants.
    Matched MeSH terms: Mass Spectrometry
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