Displaying publications 541 - 560 of 951 in total

Abstract:
Sort:
  1. Concentrations and profiles of urinary polycyclic aromatic hydrocarbon metabolites (OH-PAHs) in several Asian countries
    Guo Y, Senthilkumar K, Alomirah H, Moon HB, Minh TB, Mohd MA, et al.
    Environ Sci Technol, 2013 Mar 19;47(6):2932-8.
    PMID: 23409981 DOI: 10.1021/es3052262
    Concentrations of 12 hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) were determined in 306 urine samples collected from seven Asian countries (China, India, Japan, Korea, Kuwait, Malaysia, and Vietnam) by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The total concentrations of OH-PAHs found in the seven Asian countries were in the following increasing order: Malaysia (median: 2260 pg/mL) < Japan (4030 pg/mL) < China (5770 pg/mL) < India (6750 pg/mL) < Vietnam (8560 pg/mL) < Korea (9340 pg/mL) < Kuwait (10170 pg/mL). The measured urinary concentrations of 1-hydroxypyrene (1-PYR) in samples from Malaysia, Korea, and Japan (∼ 100 pg/mL) were similar to those reported for North America and Western Europe. The concentrations of 1-PYR in urine samples from China, India, and Vietnam were 4-10 times higher than those reported for other countries, thus far. Among the 12 OH-PAH compounds analyzed, hydroxynaphthalene (NAP: sum of 1-hydroxynaphthalene and 2-hydroxynaphthalene) was the dominant compound (accounting for 60-90% of total OH-PAHs), followed by hydroxyphenanthrene (PHEN: sum of 2-hydroxyphenanthrene, 3-hydroxyphenanthrene, 4-hydroxyphenanthrene, and 9-hydroxyphenanthrene [3-16%]), 2-hydroxyfluorene (3-20%), and 1-PYR (2-8%). The total daily intakes (DIs) of PAHs were estimated based on the urinary concentrations of their metabolites. The DIs of naphthalene were found to be higher for populations in Korea, Kuwait, and Vietnam (> 10 μg/day) than those of the other countries studied (∼ 5 μg/day). The DIs of phenanthrene and pyrene (> 10 μg/day) in the populations of China, India, and Vietnam were higher than those estimated for the populations in the other countries studied (∼ 5 μg/day).
    Matched MeSH terms: Tandem Mass Spectrometry
  2. Flavonoids and triterpenes from the leaves of Artocarpus fulvicortex
    Jamil S, Taherb M, Sirat HM, Othman NA
    Nat Prod Commun, 2012 Dec;7(12):1587-8.
    PMID: 23413558
    Five flavonoids, 5-hydroxy-(6:7,3':4')-di(2,2-dimethylpyrano)flavone 1, carpachromene 2, cycloartocarpesin 3, norartocarpetin 4 and 2'-hydroxy-4,4',6'-trimethoxychalcone 5, along with three triterpenes, friedelin 6, lupeol 7 and 13-sitosterol 8 were isolated for the first time from the leaves of Artocarpus fulvicortex F.M. Jarrett. The structures of these compounds were established by analysis of their spectroscopic (1D and 2D NMR) and spectrometric (MS) data, as well as by comparison of these with those reported in the literature.
    Matched MeSH terms: Mass Spectrometry
  3. Profiling of metabolites in oil palm mesocarp at different stages of oil biosynthesis
    Neoh BK, Teh HF, Ng TL, Tiong SH, Thang YM, Ersad MA, et al.
    J Agric Food Chem, 2013 Feb 27;61(8):1920-7.
    PMID: 23384169 DOI: 10.1021/jf304561f
    Oil palm is one of the most productive oil producing crops and can store up to 90% oil in its fruit mesocarp. However, the biosynthetic regulation and drivers of palm mesocarp development are still not well understood. Multiplatform metabolomics technology was used to profile palm metabolites during six critical stages of fruit development in order to better understand lipid biosynthesis. Significantly higher amino acid levels were observed in palm mesocarp preceding lipid biosynthesis. Nucleosides were found to be in high concentration during lipid biosynthesis, whereas levels of metabolites involved in the tricarboxylic acid cycle were more concentrated during early fruit development. Apart from insights into the regulation of metabolites during fruit development in oil palm, these results provide potentially useful metabolite yield markers and genes of interest for use in breeding programs.
    Matched MeSH terms: Mass Spectrometry
  4. Concentrations of trace elements in marine fish and its risk assessment in Malaysia
    Agusa T, Kunito T, Yasunaga G, Iwata H, Subramanian A, Ismail A, et al.
    Mar Pollut Bull, 2005;51(8-12):896-911.
    PMID: 16023148
    Concentrations of trace elements (V, Cr, Mn, Co, Cu, Zn, Ga, Se, Rb, Sr, Mo, Ag, Cd, Sn, Sb, Cs, Ba, Hg, Tl, Pb and Bi) were determined in muscle and liver of 12 species of marine fish collected from coastal areas in Malaysia. Levels of V, Cr, Mn, Co, Cu, Zn, Ga, Sr, Mo, Ag, Cd, Sn, Ba and Pb in liver were higher than those in muscle, whereas Rb and Cs concentrations showed the opposite trend. Positive correlations between concentrations in liver and muscle were observed for all the trace elements except Cu and Sn. Copper, Zn, Se, Ag, Cd, Cs and Hg concentrations in bigeye scads from the east coast of the Peninsular Malaysia were higher than those from the west, whereas V showed the opposite trend. The high concentration of V in the west coast might indicate oil contamination in the Strait of Malacca. To evaluate the health risk to Malaysian population through consumption of fish, intake rates of trace elements were estimated on the basis of the concentrations of trace elements in muscle of fish and daily fish consumption. Some specimens of the marine fish had Hg levels higher than the guideline value by US Environmental Protection Agency (EPA), indicating that consumption of these fish at the present rate may be hazardous to Malaysian people. To our knowledge, this is the first study on multielemental accumulation in marine fish from the Malaysian coast.
    Matched MeSH terms: Mass Spectrometry
  5. Fulltext The effects of Secondhand Smoke (SHS) exposure on microvascular endothelial function among healthy women
    Sanip Z, Hanaffi SH, Ahmad I, Yusoff SS, Rasool AH, Yusoff HM
    Tob Induc Dis, 2015;13(1):32.
    PMID: 26346914 DOI: 10.1186/s12971-015-0052-9
    BACKGROUND: Studies have demonstrated that secondhand smoke (SHS) exposure could impair endothelial function. However, the effect of SHS exposure specifically on microvascular endothelial function is not well understood. This study aimed to determine the effects of SHS exposure on microvascular endothelial function among non-smoking, generally healthy women.

    FINDINGS: We studied 127 women; and based on their hair nicotine levels measured using gas chromatography-mass spectrometry, 25 of them were categorized as having higher hair nicotine levels, 25 were grouped as having lower hair nicotine and 77 women were grouped into the non-detected group. The non-detected group did not have detectable levels of hair nicotine. Anthropometry, blood pressure (BP), lipid profile and high-sensitivity C-reactive protein (hsCRP) were measured accordingly. Microvascular endothelial function was assessed non-invasively using laser Doppler fluximetry and the process of iontophoresis involving acetylcholine and sodium nitroprusside as endothelium-dependent and endothelium-independent vasodilators respectively. The mean hair nicotine levels for higher and lower hair nicotine groups were 0.74 (1.04) and 0.05 (0.01) ng/mg respectively. There were no significant differences in anthropometry, BP, lipid profile and hsCRP between these groups. There were also no significant differences in the microvascular perfusion and endothelial function between these groups.

    CONCLUSION: In this study, generally healthy non-smoking women who have higher, lower and non-detected hair nicotine levels did not show significant differences in their microvascular endothelial function. Low levels of SHS exposure among generally healthy non-smoking women may not significantly impair their microvascular endothelial function.

    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  6. Fulltext Antihyperglycemic Effect of Methanol Extract of Syzygium polyanthum (Wight.) Leaf in Streptozotocin-Induced Diabetic Rats
    Widyawati T, Yusoff NA, Asmawi MZ, Ahmad M
    Nutrients, 2015 Sep;7(9):7764-80.
    PMID: 26389944 DOI: 10.3390/nu7095365
    Syzygium polyanthum (S. polyanthum), a plant belonging to Myrtaceae, is widely used in Indonesian and Malaysian cuisines. Diabetic patients in Indonesia also commonly use it as a traditional medicine. Hence, this study was conducted to investigate the antihyperglycemic effect of the methanol extract (ME) of S. polyanthum leaf and its possible mechanisms of action. To test for hypoglycemic activity, ME was administered orally to normal male Sprague Dawley rats after a 12-h fast. To further test for antihyperglycemic activity, the same treatment was administered to glucose-loaded (intraperitoneal glucose tolerance test, IPGTT) and streptozotocin (STZ)-induced diabetic rats, respectively. Hypoglycemic test in normal rats did not show significant reduction in blood glucose levels (BGLs) by the extract. Furthermore, IPGTT conducted on glucose-loaded normal rats also did not show significant reduction of BGLs. However, repeated administration of metformin and three doses of ME (250, 500 and 1000 mg/kg) for six days caused significant reduction of fasting BGLs in STZ-induced diabetic rats. The possible mechanisms of action of S. polyanthum antihyperglycemic activity were assessed by measurement of intestinal glucose absorption and glucose uptake by isolated rat abdominal muscle. It was found that the extract not only inhibited glucose absorption from the intestine but also significantly increased glucose uptake in muscle tissue. A preliminary phytochemical qualitative analysis of ME indicated the presence of tannins, glycosides, flavonoids, alkaloids and saponins. Additionally, Gas Chromatography-Mass Spectrometry (GC-MS) analysis detected squalene. In conclusion, S. polyanthum methanol leaf extract exerts its antihyperglycemic effect possibly by inhibiting glucose absorption from the intestine and promoting glucose uptake by the muscles.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  7. Fulltext Decreased expression of alpha-2-HS glycoprotein in the sera of rats treated with Eurycoma longifolia extract
    Chen Y, Phang WM, Mu AK, Chan CK, Low BS, Sasidharan S, et al.
    Front Pharmacol, 2015;6:211.
    PMID: 26441666 DOI: 10.3389/fphar.2015.00211
    Eurycoma longifolia is a Malaysian native herb that has been widely used as an aphrodisiac and a remedy for andropause. Although the physiological effects of the plant extract were predicted as a result of the alterations in protein expression, the key protein(s) involved in these alterations are still unclear. In the present study, we have investigated the effect of standardized E. longifolia extract on serum protein expression up to 28 days following oral administration in rats. Serum protein profiles were analyzed by 2-dimensional electrophoresis, and altered proteins were identified via mass spectrometry. We observed that alpha-2-HS glycoprotein (AHS) was significantly decreased in the serum of experimentally treated rats compared to pre-treated animals. Moreover, reduction in AHS was confirmed using competitive enzyme-linked immunosorbent assay. AHS expression is known to be associated with insulin resistance and diabetes. Our data indicated that serum AHS was reduced in rats treated with standardized E. longifolia extract, and therefore form a prelude for further investigation into the effects of this natural extract in animal models involving infertility and diabetes.
    Matched MeSH terms: Mass Spectrometry
  8. Current status of arsenic exposure and social implication in the Mekong River basin of Cambodia
    Phan K, Kim KW, Huoy L, Phan S, Se S, Capon AG, et al.
    Environ Geochem Health, 2016 Jun;38(3):763-72.
    PMID: 26298061 DOI: 10.1007/s10653-015-9759-z
    To evaluate the current status of arsenic exposure in the Mekong River basin of Cambodia, field interview along with urine sample collection was conducted in the arsenic-affected area of Kandal Province, Cambodia. Urine samples were analyzed for total arsenic concentrations by inductively coupled plasma mass spectrometry. As a result, arsenicosis patients (n = 127) had As in urine (UAs) ranging from 3.76 to 373 µg L(-1) (mean = 78.7 ± 69.8 µg L(-1); median = 60.2 µg L(-1)). Asymptomatic villagers (n = 108) had UAs ranging from 5.93 to 312 µg L(-1) (mean = 73.0 ± 52.2 µg L(-1); median = 60.5 µg L(-1)). About 24.7 % of all participants had UAs greater than 100 µg L(-1) which indicated a recent arsenic exposure. A survey found that females and adults were more likely to be diagnosed with skin sign of arsenicosis than males and children, respectively. Education level, age, gender, groundwater drinking period, residence time in the village and amount of water drunk per day may influence the incidence of skin signs of arsenicosis. This study suggests that residents in Kandal study area are currently at risk of arsenic although some mitigation has been implemented. More commitment should be made to address this public health concern in rural Cambodia.
    Matched MeSH terms: Mass Spectrometry
  9. Baseline distribution and sources of linear alkyl benzenes (LABs) in surface sediments from Brunei Bay, Brunei
    Alkhadher SAA, Zakaria MP, Yusoff FM, Kannan N, Suratman S, Keshavarzifard M, et al.
    Mar Pollut Bull, 2015 Dec 15;101(1):397-403.
    PMID: 26478457 DOI: 10.1016/j.marpolbul.2015.10.011
    Sewage pollution is one of major concerns of coastal and shoreline settlements in Southeast Asia, especially Brunei. The distribution and sources of LABs as sewage molecular markers were evaluated in surface sediments collected from Brunei Bay. The samples were extracted, fractionated and analyzed using gas chromatography- mass spectrometry (GC-MS). LABs concentrations ranged from 7.1 to 41.3 ng g(-1) dry weight (dw) in surficial sediments from Brunei Bay. The study results showed LABs concentrations variably due to the LABs intensity and anthropogenic influence along Brunei Bay in recent years. The ratio of Internal to External isomers (I/E ratio) of LABs in sediment samples from Brunei Bay ranged from 0.56 to 2.17 along Brunei Bay stations, indicating that the study areas were receiving primary and secondary effluents. This is the first study carried out to assess the distribution and sources of LABs in surface sediments from Brunei Bay, Brunei.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  10. Blowfly Larval Tissues as a Secondary Detector for Determining Paraquat-Related Death in Rabbit Carcass
    Lawai V, Abdul Rahim NA, Ngaini Z
    J Forensic Sci, 2015 11;60(6):1620-4.
    PMID: 26382214 DOI: 10.1111/1556-4029.12852
    Paraquat poisoning is commonly associated with suicide or homicide in Malaysia. In a case involving advanced body decomposition, pathological analysis regarding the cause of death may become difficult or almost impossible. Insects serve as common alternative matrix for poison detection in forensic analysis. Paraquat detection via secondary bioaccumulation in fly larvae tissue has never been reported. In this study, tissues from blowfly larvae collected from a rabbit carcass with paraquat poisoning were analyzed for secondary bioaccumulation. Larvae samples were collected and analyzed using liquid-liquid extraction. The detection was performed via reduction of quaternary ammonium presence in paraquat and analyzed using gas chromatography-mass spectrometry (GC-MS) with selected ion monitoring mode (SIM mode). GC-MS showed the elution of reduced paraquat was at retention time 12.8 min. Blowfly larvae tissue has proven useful as a secondary detector in paraquat-related deaths.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  11. Simultaneous determination of three organophosphorus pesticides in different food commodities by gas chromatography with mass spectrometry
    Vijaya Bhaskar Reddy A, Yusop Z, Jaafar J, Bin Aris A, Abdul Majid Z, Umar K, et al.
    J Sep Sci, 2016 Jun;39(12):2276-83.
    PMID: 27095506 DOI: 10.1002/jssc.201600155
    A sensitive and selective gas chromatography with mass spectrometry method was developed for the simultaneous determination of three organophosphorus pesticides, namely, chlorpyrifos, malathion, and diazinon in three different food commodities (milk, apples, and drinking water) employing solid-phase extraction for sample pretreatment. Pesticide extraction from different sample matrices was carried out on Chromabond C18 cartridges using 3.0 mL of methanol and 3.0 mL of a mixture of dichloromethane/acetonitrile (1:1 v/v) as the eluting solvent. Analysis was carried out by gas chromatography coupled with mass spectrometry using selected-ion monitoring mode. Good linear relationships were obtained in the range of 0.1-50 μg/L for chlorpyrifos, and 0.05-50 μg/L for both malathion and diazinon pesticides. Good repeatability and recoveries were obtained in the range of 78.54-86.73% for three pesticides under the optimized experimental conditions. The limit of detection ranged from 0.02 to 0.03 μg/L, and the limit of quantification ranged from 0.05 to 0.1 μg/L for all three pesticides. Finally, the developed method was successfully applied for the determination of three targeted pesticides in milk, apples, and drinking water samples each in triplicate. No pesticide was found in apple and milk samples, but chlorpyrifos was found in one drinking water sample below the quantification level.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  12. Fulltext In Vitro Analysis of Metabolites Secreted during Infection of Lung Epithelial Cells by Cryptococcus neoformans
    Liew KL, Jee JM, Yap I, Yong PV
    PLoS One, 2016;11(4):e0153356.
    PMID: 27054608 DOI: 10.1371/journal.pone.0153356
    Cryptococcus neoformans is an encapsulated basidiomycetous yeast commonly associated with pigeon droppings and soil. The opportunistic pathogen infects humans through the respiratory system and the metabolic implications of C. neoformans infection have yet to be explored. Studying the metabolic profile associated with the infection could lead to the identification of important metabolites associated with pulmonary infection. Therefore, the aim of the study was to simulate cryptococcal infection at the primary site of infection, the lungs, and to identify the metabolic profile and important metabolites associated with the infection at low and high multiplicity of infections (MOI). The culture supernatant of lung epithelial cells infected with C. neoformans at MOI of 10 and 100 over a period of 18 hours were analysed using gas chromatography mass spectrometry. The metabolic profiles obtained were further analysed using multivariate analysis and the pathway analysis tool, MetaboAnalyst 2.0. Based on the results from the multivariate analyses, ten metabolites were selected as the discriminatory metabolites that were important in both the infection conditions. The pathways affected during early C. neoformans infection of lung epithelial cells were mainly the central carbon metabolism and biosynthesis of amino acids. Infection at a higher MOI led to a perturbance in the β-alanine metabolism and an increase in the secretion of pantothenic acid into the growth media. Pantothenic acid production during yeast infection has not been documented and the β-alanine metabolism as well as the pantothenate and CoA biosynthesis pathways may represent underlying metabolic pathways associated with disease progression. Our study suggested that β-alanine metabolism and the pantothenate and CoA biosynthesis pathways might be the important pathways associated with cryptococcal infection.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  13. Fulltext Temporal regulation of proteome profile in the fruit fly, Drosophila melanogaster
    Subramanian P, Jayapalan JJ, Abdul-Rahman PS, Arumugam M, Hashim OH
    PeerJ, 2016;4:e2080.
    PMID: 27257555 DOI: 10.7717/peerj.2080
    Background. Diurnal rhythms of protein synthesis controlled by the biological clock underlie the rhythmic physiology in the fruit fly, Drosophila melanogaster. In this study, we conducted a proteome-wide investigation of rhythmic protein accumulation in D. melanogaster. Materials and Methods. Total protein collected from fly samples harvested at 4 h intervals over the 24 h period were subjected to two-dimensional gel electrophoresis, trypsin digestion and MS/MS analysis. Protein spots/clusters were identified with MASCOT search engine and Swiss-Prot database. Expression of proteins was documented as percentage of volume contribution using the Image Master 2D Platinum software. Results. A total of 124 protein spots/clusters were identified using MS/MS analysis. Significant variation in the expression of 88 proteins over the 24-h period was observed. A relatively higher number of proteins was upregulated during the night compared to the daytime. The complexity of temporal regulation of the D. melanogaster proteome was further reflected from functional annotations of the differently expressed proteins, with those that were upregulated at night being restricted to the heat shock proteins and proteins involved in metabolism, muscle activity, protein synthesis/folding/degradation and apoptosis, whilst those that were overexpressed in the daytime were apparently involved in metabolism, muscle activity, ion-channel/cellular transport, protein synthesis/folding/degradation, redox homeostasis, development and transcription. Conclusion. Our data suggests that a wide range of proteins synthesized by the fruit fly, D. melanogaster, is under the regulation of the biological clock.
    Matched MeSH terms: Tandem Mass Spectrometry
  14. Enzyme-assisted extraction and identification of antioxidative and α-amylase inhibitory peptides from Pinto beans (Phaseolus vulgaris cv. Pinto)
    Ngoh YY, Gan CY
    Food Chem, 2016 Jan 1;190:331-7.
    PMID: 26212978 DOI: 10.1016/j.foodchem.2015.05.120
    Antioxidant and α-amylase inhibitor peptides were successfully extracted from Pinto bean protein isolate (PBPI) using Protamex. A factorial design experiment was conducted and the effects of extraction time, pH and temperature were studied. pH 7.5, extraction time of 1h, S/E ratio of 10 (w/w) and temperature of 50 °C gave the highest antioxidant activities (i.e., ABTS scavenging activity (53.3%) and FRAP value (3.71 mM)), whereas pH 6.5 with the same extraction time, S/E ratio and temperature, gave the highest α-amylase inhibitory activity (57.5%). It was then fractioned using membrane ultrafiltration with molecular weight cutoffs of 100, 50, 30, 10 and 3 kDa. Peptide fraction <3 kDa, which exhibited the highest antioxidant activities (i.e., ABTS (42.2%) and FRAP (0.81 mM)) and α-amylase inhibitory activity (62.1%), was then subjected to LCMS and MS/MS analyses. Six sequences were identified for antioxidant peptides, whereas seven peptides for α-amylase inhibitor.
    Matched MeSH terms: Tandem Mass Spectrometry
  15. Fulltext Mosquitocidal and Oviposition Repellent Activities of the Extracts of Seaweed Bryopsis pennata on Aedes aegypti and Aedes albopictus
    Yu KX, Wong CL, Ahmad R, Jantan I
    Molecules, 2015;20(8):14082-102.
    PMID: 26247928 DOI: 10.3390/molecules200814082
    The ever-increasing threat from infectious diseases and the development of insecticide resistance in mosquito populations drive the global search for new natural insecticides. The aims of this study were to evaluate the mosquitocidal activity of the extracts of seaweed Bryopsis pennata against dengue vectors Aedes aegypti and Aedes albopictus, and determine the seaweed's toxic effect on brine shrimp nauplii (as a non-target organism). In addition, the chemical compositions of the active larvicidal extract and fraction were analyzed by using liquid chromatography-mass spectrometry (LC-MS). Chloroform extract exhibited strong ovicidal activity (with LC50 values of 229.3 and 250.5 µg/mL) and larvicidal activity against Ae. aegypti and Ae. albopictus. The larvicidal potential of chloroform extract was further ascertained when its A7 fraction exhibited strong toxic effect against Ae. aegypti (LC50 = 4.7 µg/mL) and Ae. albopictus (LC50 = 5.3 µg/mL). LC-MS analysis of the chloroform extract gave a tentative identification of 13 compounds; Bis-(3-oxoundecyl) tetrasulfide was identified as the major compound in A7 fraction. Methanol extract showed strong repellent effect against female oviposition, along with weak adulticidal activity against mosquito and weak toxicity against brine shrimp nauplii. The mosquitocidal results of B. pennata suggest further investigation for the development of effective insecticide.
    Matched MeSH terms: Mass Spectrometry
  16. Fulltext Non-Lethal Heat Shock of the Asian Green Mussel, Perna viridis, Promotes Hsp70 Synthesis, Induces Thermotolerance and Protects Against Vibrio Infection
    Aleng NA, Sung YY, MacRae TH, Abd Wahid ME
    PLoS One, 2015;10(8):e0135603.
    PMID: 26288319 DOI: 10.1371/journal.pone.0135603
    Mild heat stress promotes thermotolerance and protection against several different stresses in aquatic animals, consequences correlated with the accumulation of heat shock protein 70 (Hsp70). The purpose of this study was to determine if non-lethal heat shock (NLHS) of the Asian green mussel, Perna viridis, an aquatic species of commercial value, promoted the production of Hsp70 and enhanced its resistance to stresses. Initially, the LT50 and LHT for P. viridis were determined to be 42°C and 44°C, respectively, with no heat shock induced death of mussels at 40°C or less. Immunoprobing of western blots revealed augmentation of constitutive (PvHsp70-1) and inducible (PvHsp70-2) Hsp70 in tissue from adductor muscle, foot, gill and mantel of P. viridis exposed to 38°C for 30 min followed by 6 h recovery, NLHS conditions for this organism. Characterization by liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed that PvHsp70-1 and PvHsp70-2 respectively corresponded most closely to Hsp70 from P. viridis and Mytilus galloprovincialis. Priming of adult mussels with NLHS promoted thermotolerance and increased resistance to V. alginolyticus. The induction of Hsp70 in parallel with enhanced thermotolerance and improved protection against V. alginolyticus, suggests Hsp70 functions in P. viridis as a molecular chaperone and as a stimulator of the immune system.
    Matched MeSH terms: Mass Spectrometry
  17. Fulltext Antioxidative Effects and Inhibition of Human Low Density Lipoprotein Oxidation In Vitro of Polyphenolic Compounds in Flammulina velutipes (Golden Needle Mushroom)
    Rahman MA, Abdullah N, Aminudin N
    Oxid Med Cell Longev, 2015;2015:403023.
    PMID: 26180589 DOI: 10.1155/2015/403023
    Dietary polyphenolic compounds mediate polynomial actions in guarding against multiple diseases. Atherosclerosis is an oxidative stress driven pathophysiological complication where free radical induced oxidative modification of low density lipoprotein (LDL) plays the ground breaking role. Mushrooms have been highly regarded for possessing an antioxidant arsenal. Polyphenolic compounds present in dietary mushrooms seem pertinent in withstanding LDL oxidation en route to controlling atherosclerosis. In this study, the antioxidative effect of five solvent fractions consisting of methanol : dichloromethane (M : DCM), hexane (HEX), dichloromethane (DCM), ethyl acetate (EA), and aqueous residue (AQ) of Flammulina velutipes was evaluated. M : DCM fraction showed the most potent 2,2-diphenyl-1-picrylhydrazyl radical scavenging effect with IC50 of 0.86 mg/mL and total phenolic content of 56.36 gallic acid equivalent/g fraction. In LDL oxidation inhibitory tests, M : DCM fraction at 1 µg/mL concentration mostly lengthened the lag time (125 mins) of conjugated diene formation and inhibited the formation of thiobarbituric acid reactive substances (48.71%, at 1 mg/mL concentration). LC-MS/MS analyses of M : DCM fraction identified the presence of polyphenolic substances protocatechuic acid, p-coumaric, and ellagic acid. These chain-breaking polyphenolics might impart the antioxidative effects of F. velutipes. Thus, mushroom-based dietary polyphenolic compounds might be implicated in slowing down the progression of atherosclerosis.
    Matched MeSH terms: Tandem Mass Spectrometry
  18. Fulltext Synthesis, spectroscopic and chromatographic studies of sunflower oil biodiesel using optimized base catalyzed methanolysis
    Naureen R, Tariq M, Yusoff I, Chowdhury AJ, Ashraf MA
    Saudi J Biol Sci, 2015 May;22(3):332-9.
    PMID: 25972756 DOI: 10.1016/j.sjbs.2014.11.017
    Methyl esters from vegetable oils have attracted a great deal of interest as substitute for petrodiesel to reduce dependence on imported petroleum and provide an alternate and sustainable source for fuel with more benign environmental properties. In the present study biodiesel was prepared from sunflower seed oil by transesterification by alkali-catalyzed methanolysis. The fuel properties of sunflower oil biodiesel were determined and discussed in the light of ASTM D6751 standards for biodiesel. The sunflower oil biodiesel was chemically characterized with analytical techniques like FT-IR, and NMR ((1)H and (13)C). The chemical composition of sunflower oil biodiesel was determined by GC-MS. Various fatty acid methyl esters (FAMEs) were identified by retention time data and verified by mass fragmentation patterns. The percentage conversion of triglycerides to the corresponding methyl esters determined by (1)H NMR was 87.33% which was quite in good agreement with the practically observed yield of 85.1%.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  19. Other factors to consider in the formation of chloropropandiol fatty esters in oil processes
    Ramli MR, Siew WL, Ibrahim NA, Kuntom A, Abd Razak RA
    Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2015;32(6):817-24.
    PMID: 25798697 DOI: 10.1080/19440049.2015.1032368
    This paper examines the processing steps of extracting palm oil from fresh fruit bunches in a way that may impact on the formation of chloropropandiol fatty esters (3-MCPD esters), particularly during refining. Diacylglycerols (DAGs) do not appear to be a critical factor when crude palm oils are extracted from various qualities of fruit bunches. Highly hydrolysed oils, in spite of the high free fatty acid (FFA) contents, did not show exceptionally high DAGs, and the oils did not display a higher formation of 3-MCPD esters upon heat treatment. However, acidity measured in terms of pH appears to have a strong impact on 3-MCPD ester formation in the crude oil when heated at high temperatures. The differences in the extraction process of crude palm oil from current commercial processes and that from a modified experimental process showed clearly the effect of acidity of the oil on the formation of 3-MCPD esters. This paper concludes that the washing or dilution step in palm oil mills removes the acidity of the vegetative materials and that a well-optimised dilution/washing step in the extraction process will play an important role in reducing formation of 3-MCPD esters in crude palm oil upon further heat processing.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  20. Pregnenolone metabolites in rat testis: endogenous concentrations, and intracellular distribution in whole testes during incubation in vitro
    Pertiwi AK, Kwan TK, Gower DB
    J Steroid Biochem Mol Biol, 2002 Aug;81(4-5):363-7.
    PMID: 12361726
    The intracellular movements of pregnenolone in rat testes were investigated. Whole testes were incubated in the presence or absence of pregnenolone (2.5mM) in the medium for 120 min (in some studies 30, 60, and 90 min). The testes were homogenised, subcellular fractions prepared and analysed in quadruplicate for steroid content by gas chromatography-mass spectrometry with selected ion monitoring. Quantification of pregnenolone and 11 of its metabolites, obtained from non-incubated whole testes, provided values for endogenous amounts. Pregnenolone was the only steroid of quantitative importance found initially in the mitochondrial fraction but was subsequently found in the microsomal fraction, where metabolism occurred. Identification and quantification of metabolites indicated that both classical pathways for testosterone production were operating, with the 4-en-3-oxosteroid pathway predominating. By 120 min, virtually all pregnenolone metabolites, including pregnenolone itself, were found in the cytosol, consistent with an overall movement from mitochondria to endoplasmic reticulum to cytosol.
    Matched MeSH terms: Mass Spectrometry
Related Terms
Filters
Contact Us

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

External Links