Displaying publications 1 - 20 of 686 in total

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  1. Lee SY, Mediani A, Ismail IS, Maulidiani, Abas F
    BMC Complement Altern Med, 2019 Jan 07;19(1):7.
    PMID: 30616569 DOI: 10.1186/s12906-018-2413-4
    BACKGROUND: Neptunia oleracea is a plant cultivated as vegetable in Southeast Asia. Previous works have revealed the potential of this plant as a source of natural antioxidants and α-glucosidase inhibitors. Continuing our interest on this plant, the present work is focused in identification of the bioactive compounds from different polarity fractions of N. oleracea, namely hexane (HF), chloroform (CF), ethyl acetate (EF) and methanol (MF).

    METHODS: The N. oleracea fractions were obtained using solid phase extraction (SPE). A metabolomics approach that coupled the use of proton nuclear magnetic resonance (1H NMR) with multivariate data analysis (MVDA) was applied to distinguish the metabolite variations among the N. oleracea fractions, as well as to assess the correlation between metabolite variation and the studied bioactivities (DPPH free radical scavenging and α-glucosidase inhibitory activities). The bioactive fractions were then subjected to ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) analysis to profile and identify the potential bioactive constituents.

    RESULTS: The principal component analysis (PCA) discriminated EF and MF from the other fractions with the higher distributions of phenolics. Partial least squares (PLS) analysis revealed a strong correlation between the phenolics and the studied bioactivities in the EF and the MF. The UHPLC-MS/MS profiling of EF and MF had tentatively identified the phenolics present. Together with some non-phenolic metabolites, a total of 37 metabolites were tentatively assigned.

    CONCLUSIONS: The findings of this work supported that N. oleracea is a rich source of phenolics that can be potential antioxidants and α-glucosidase inhibitors for the management of diabetes. To our knowledge, this study is the first report on the metabolite-bioactivity correlation and UHPLC-MS/MS analysis of N. oleracea fractions.

    Matched MeSH terms: Chromatography, High Pressure Liquid
  2. Wong PL, Fauzi NA, Mohamed Yunus SN, Abdul Hamid NA, Abd Ghafar SZ, Azizan A, et al.
    Molecules, 2020 Jul 06;25(13).
    PMID: 32640504 DOI: 10.3390/molecules25133067
    Plants and plant-based products have been used for a long time for medicinal purposes. This study aimed to determine the antioxidant and anti-α-glucosidase activities of eight selected underutilized plants in Malaysia: Leucaena leucocephala, Muntingia calabura, Spondias dulcis, Annona squamosa, Ardisia elliptica, Cynometra cauliflora, Ficus auriculata, and Averrhoa bilimbi. This study showed that the 70% ethanolic extract of all plants exhibited total phenolic content (TPC) ranging from 51 to 344 mg gallic acid equivalent (GAE)/g dry weight. A. elliptica showed strong 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide (NO) scavenging activities, with half maximal inhibitory concentration (IC50) values of 2.17 and 49.43 μg/mL, respectively. Most of the tested plant extracts showed higher inhibition of α-glucosidase enzyme activity than the standard, quercetin, particularly A. elliptica, F. auriculata, and M. calabura extracts with IC50 values of 0.29, 0.36, and 0.51 μg/mL, respectively. A total of 62 metabolites including flavonoids, triterpenoids, benzoquinones, and fatty acids were tentatively identified in the most active plant, i.e., A. elliptica leaf extract, by using ultra-high-performance liquid chromatography (UHPLC)-electrospray ionization (ESI) Orbitrap MS. This study suggests a potential natural source of antioxidant and α-glucosidase inhibitors from A. elliptica.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  3. Hellal K, Mediani A, Ismail IS, Tan CP, Abas F
    Food Res Int, 2021 02;140:110046.
    PMID: 33648271 DOI: 10.1016/j.foodres.2020.110046
    Lupinus albus or white lupine has recently received increase attention for its medicinal values. Several studies have described the hypoglycemic effect of the white lupine, which is known as a food plant with potential value for treatment of diabetes. This study provides useful information for the identification and quantification of compounds in L. albus fractions by proton nuclear magnetic resonance (1H NMR) spectroscopy. In total, 35 metabolites were identified from L. albus fractions.Principal component analysis (PCA) was used as a multivariate projection method for visualizing the different composition of four different fractions. The bioactivities of fractions with different polarity obtained from the extract of L. albus seeds are reported. Among the fractions studied, the chloroform fraction (CF) exhibits a high free radical scavenging (DPPH) and α-glucosidase inhibitory activities with IC50 values of 24.08 and 20.08 μg/mL, respectively. A partial least-squares analyses (PLS) model had been successfully performed to correlate the potential active metabolites with the corresponding biological activities. Metabolites containing proline, caprate, asparagine, lupinoisolone C, hydroxyiso lupalbigenin and some unknown compounds show high correlation with the bioactivities studied. Moreover, the structural identification in the active fraction was supported by ultrahigh-performance-liquid chromatography-electrospray ionization tandem mass spectrometry (UHPLC-ESI-MS/MS) analysis. A total of 21 metabolites were tentatively identified from MS/MS data by comparison with previously reported data. Most of these compounds are isoflavonoids without known biological activity. This information may be useful for developing functional food from L. albus with potential application in the management of diabetes.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  4. Chandradevan M, Simoh S, Mediani A, Ismail NH, Ismail IS, Abas F
    PMID: 32047522 DOI: 10.1155/2020/3238561
    This study aimed to determine the total phenolic content, DPPH scavenging, α-glucosidase, and nitric oxide (NO) inhibition of Gynura procumbens and Cleome gynandra extracts obtained with five different ethanolic concentrations. The findings showed that the 100% ethanolic extract of G. procumbens had the highest phenolic content and the lowest IC50 values for DPPH scavenging and NO inhibition activity compared to the properties of the other extracts. For C. gynandra, the 20% and 100% ethanolic extracts had comparably high total phenolic contents, and the latter possessed the lowest IC50 value in the NO inhibition assay. In addition, the 20% ethanolic extract of C. gynandra had the lowest IC50 value in the DPPH scavenging assay. However, none of the extracts from either herb had the ability to inhibit α-glucosidase enzyme. Pearson correlation analysis indicated a strong relationship between the phenolic content and DPPH scavenging activity in both herb extracts. A moderately strong relationship was also observed between the phenolic content and NO inhibition in G. procumbens extracts and not in C. gynandra extracts. The UHPLC-ESI-Orbitrap-MS revealed major phenolics from the groups of hydroxycinnamic acids, hydroxybenzoic acids, and flavonoid derivatives from both herbs, which could be the key contributors to their bioactivities. Among the identified metabolites, 24 metabolites were tentatively assigned for the first time from both species of studied herbs. These two herbs could be recommended as prospective natural products with valuable medicinal properties.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  5. Noorashikin MS, Raoov M, Mohamad S, Abas MR
    Int J Mol Sci, 2013;14(12):24531-48.
    PMID: 24351832 DOI: 10.3390/ijms141224531
    A cloud point extraction (CPE) process using non-ionic surfactant (DC193C) to extract selected paraben compounds from water samples was investigated using reversed phase high performance liquid chromatography (RP-HPLC). The CPE process with the presence of β-cyclodextrin (βCD) functionalized ionic liquid as a modifier (CPE-DC193C-βCD-IL) is a new extraction technique that has been applied on the optimization of parameters, i.e., pH, βCD-IL concentration and phase volume ratio. This CPE-DC193C-βCD-IL method is facilitated at 30 °C, showing great losses of water content in the surfactant-rich phase, resulting in a high pre-concentration factor and high distribution coefficient. The developed method CPE-DC193C-βCD-IL did show enhanced properties compared to the CPE method without the modifier (CPE-DC193C). The developed method of CPE-DC193C-βCD-IL gives an excellent performance on the detection of parabens from water samples with the limit of detection falling in the range of 0.013-0.038 µg mL-1. Finally, the inclusion complex formation, hydrogen bonding, and π-π interaction between the βCD-IL, benzyl paraben (ArP), and DC 193C were proven using 1H NMR and 2D NOESY spectroscopy.
    Matched MeSH terms: Chromatography, High Pressure Liquid*
  6. Tay KS, Rahman NA, Abas MR
    Environ Sci Pollut Res Int, 2013 May;20(5):3115-21.
    PMID: 23054788 DOI: 10.1007/s11356-012-1223-3
    This study investigated the degradation pathway of metoprolol, a widely used β-blocker, in the ozonation via the identification of generated ozonation by-products (OPs). Structure elucidation of OPs was performed using HPLC coupled with quadrupole time-of-flight high-resolution mass spectrometry. Seven OPs were identified, and four of these have not been reported elsewhere. Identified OPs of metoprolol included aromatic ring breakdown by-products; aliphatic chain degraded by-products and aromatic ring mono-, di-, and tetrahydroxylated derivatives. Based on the detected OPs, metoprolol could be degraded through aromatic ring opening reaction via reaction with ozone (O3) and degradation of aliphatic chain and aromatic ring via reaction with hydroxyl radical (•OH).
    Matched MeSH terms: Chromatography, High Pressure Liquid
  7. Nawaz M, Arayne MS, Sultana N, Abbas HF
    PMID: 25300038 DOI: 10.1016/j.saa.2014.08.152
    This work describes a RP-HPLC method for the determination and interaction studies of cefpirome with ACE-inhibitors (captopril, enalapril and lisinopril) in various buffers. The separation and interaction of cefpirome with ACE-inhibitors was achieved on a Purospher Star, C18 (5 μm, 250×4.6 mm) column. Mobile phase consisted of methanol: water (80:20, v/v, pH 3.3); however, for the separation of lisinopril, it was modified to methanol-water (40:60, v/v, pH 3.3) and pumped at a flow rate of 1 mL min(-1). In all cases, UV detection was performed at 225 nm. Interactions were carried out in physiological pH i.e., pH 1 (simulated gastric juice), 4 (simulated full stomach), 7.4 (blood pH) and 9 (simulated GI), drug contents were analyzed by reverse phase high performance liquid chromatography. Method was found linear in the concentration range of 1.0-50.0 μg mL(-1) with correlation coefficient (r(2)) of 0.999. Precision (RSD%) was less than 2.0%, indicating good precision of the method and accuracy was 98.0-100.0%. Furthermore, cefpirome-ACE-inhibitors' complexes were also synthesized and results were elucidated on the basis of FT-IR, and (1)H NMR. The interaction results show that these interactions are pH dependent and for the co-administration of cefpirome and ACE-inhibitors, a proper interval should be given.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
  8. Lasekan O, Abbas K
    Food Chem Toxicol, 2010 Aug-Sep;48(8-9):2212-6.
    PMID: 20510332 DOI: 10.1016/j.fct.2010.05.050
    Considering the importance of tropical almond nuts as a snack item, a study was conducted to identify the flavour volatiles and acrylamide generated during the roasting of the nuts. The supercritical fluid extracted flavour components revealed 74 aroma active compounds made up of 27 hydrocarbons, 12 aldehydes, 11 ketones, 7 acids, 4 esters, 3 alcohols, 5 furan derivatives a pyrazine, and 2 unknown compounds. While low levels of acrylamide (8-86 microg/kg) were obtained in the roasted nuts, significant (P<0.05) increases occurred in concentration with increased roasting temperature and time. Carboxylic acids were the most abundant volatiles in the roasted almond nuts and less significant (P>0.05) concentration of acrylamide was generated with mild roasting and shorter roasting period.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  9. Ramli MR, Siew WL, Ibrahim NA, Kuntom A, Abd Razak RA
    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: Chromatography, High Pressure Liquid
  10. Bzour M, Zuki FM, Mispan MS, Jodeh S, Abdel-Latif M
    Bull Environ Contam Toxicol, 2019 Aug;103(2):348-353.
    PMID: 31069403 DOI: 10.1007/s00128-019-02625-x
    The residual activity of herbicides may be detrimental to the environment, requiring analysis of the persistent residues in the soil and water. A field study was conducted to measure the residues of Imidazolinone (IMI) in three Clearfield® rice field soils at three different locations in Malaysia. The analyses of IMI in the soil samples were carried out using a high-performance liquid chromatography (HPLC). These herbicides are widely used; however, few studies have been conducted on both residues, especially in the context of Malaysian soil. Residues of imazapic and imazapyr were found to fall within 0.03-0.58 µg/mL and 0.03-1.96 µg/mL, respectively, in three locations. IMI herbicides are persistent in the soil, and their residues remain for up to 85 days after application. A pre-harvest study was suggested for these herbicides on water, which will provide a clearer indicator on the use of IMI in Clearfield® rice fields.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
  11. Abdul Rahim MH, Zakaria ZA, Mohd Sani MH, Omar MH, Yakob Y, Cheema MS, et al.
    PMID: 27190528 DOI: 10.1155/2016/1494981
    The objectives of the present study were to determine the mechanisms of antinociceptive effect of methanol extract of Clinacanthus nutans (Acanthaceae) leaves (MECN) using various animal nociceptive models. The antinociceptive activity of orally administered 10% DMSO, 100 mg/kg acetylsalicylic acid (ASA), 5 mg/kg morphine, or MECN (100, 250, and 500 mg/kg) was determined using the acetic acid-induced abdominal constriction (ACT), formalin-induced paw licking (FT), and hot plate tests (HPT). The role of opioid and nitric oxide/cyclic guanosine monophosphate (NO/cGMP) systems was also investigated. The results showed that MECN produced a significant (p < 0.05) antinociceptive response in all nociceptive models with the recorded ED50 value of 279.3 mg/kg for the ACT, while, for the early and late phases of the FT, the value was >500 mg/kg or 227.7 mg/kg, respectively. This antinociceptive activity was fully antagonized by naloxone (a nonselective opioid antagonist) but was partially reversed by l-arginine (l-arg; a nitric oxide [NO] precursor), Nω-nitro-l-arginine methyl ester hydrochloride (l-NAME; an NO synthase inhibitor), or their combinations thereof. In contrast, 1H-[1,2,4]oxadiazole[4,3-a]quinoxalin-1-one (ODQ; a soluble guanylyl cyclase inhibitor) enhanced the extract's antinociception. UHPLC analysis revealed the presence of several flavonoid-based compounds with antinociceptive action. In conclusion, MECN exerted the peripherally and centrally mediated antinociceptive activity via the modulation of the opioid/NO-mediated, but cGMP-independent, systems.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  12. Chua GHI, Phang SCW, Wong YO, Ho LS, Palanisamy UD, Abdul Kadir K
    Nutrients, 2020 Nov 27;12(12).
    PMID: 33261162 DOI: 10.3390/nu12123659
    Malaysian national morbidity surveys on diabetic prevalence have shown ethnical variation among prediabetic and diabetic populations. In our attempt to understand this variation, we studied the α-tocopherol, insulin resistance, β-cell function and receptor of advanced glycation end-products (RAGE) levels, as risk factors of type 2 diabetes, among the different ethnicities. In total, 299 subjects of Malay, Chinese, Indian and aboriginal Orang Asli (OA) heritage were recruited from urban and rural areas of Malaysia by stratified random sampling. Serum α-tocopherol concentrations were measured using high performance liquid chromatography (HPLC) and insulin concentrations were measured using enzyme-linked immunosorbent assay (ELISA). In subjects with pre-diabetes, OAs had the highest α-tocopherol level, followed by Chinese and Malays (0.8938, 0.8564 and 0.6948 respectively; p < 0.05). In diabetic subjects, Malays had significantly higher RAGE levels compared to Chinese and Indians (5579.31, 3473.40 and 3279.52 pg/mL respectively, p = 0.001). Low α-tocopherol level (OR = 3.021, p < 0.05) and high insulin resistance (OR = 2.423, p < 0.05) were linked strongly to the development of pre-diabetes. Low β-cell function (OR = 5.657, p < 0.001) and high RAGE level (OR = 3.244, p < 0.05) were linked strongly to the development of diabetes from pre-diabetes. These factors might be involved in the development of diabetes, along with genetic and environmental factors.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  13. Abd Wahib SM, Wan Ibrahim WA, Sanagi MM, Kamboh MA, Abdul Keyon AS
    J Chromatogr A, 2018 Jan 12;1532:50-57.
    PMID: 29241956 DOI: 10.1016/j.chroma.2017.11.059
    A facile dispersive-micro-solid phase extraction (D-μ-SPE) method coupled with HPLC for the analysis of selected non-steroidal anti-inflammatory drugs (NSAIDs) in water samples was developed using a newly prepared magnetic sporopollenin-cyanopropyltriethoxysilane (MS-CNPrTEOS) sorbent. Sporopollenin homogenous microparticles of Lycopodium clavatum spores possessed accessible functional groups that facilitated surface modification. Simple modification was performed by functionalization with 3-cyanopropyltriethoxysilane (CNPrTEOS) and magnetite was introduced onto the biopolymer to simplify the extraction process. MS-CNPrTEOS was identified by infrared spectrometrywhile the morphology and the magnetic property were confirmed by scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM), respectively. To maximize the extraction performance of ketoprofen, ibuprofen, diclofenac and mefenamic acid using the proposed MS-CNPrTEOS, important D-μ-SPE parameters were comprehensively optimized. The optimum extraction conditions were sorbent amount, 40 mg; extraction time, 5 min; desorption time; 5 min; sample volume, 15 mL; sample pH 2.0; and salt addition, 2.5% (w/v). The feasibility of the developed method was evaluated using spiked tap water, lake water, river water and waste water samples. Results showed that ketoprofen and ibuprofen were linear in the range of 1.0-1000 μg L-1whilst diclofenac and mefenamic acid were linear in the range 0.8-500 μg L-1. The results also showed good detection limits for the studied NSAIDs in the range of 0.21-0.51 μg L-1and good recoveries for spiked water samples in the range of 85.1-106.4%. The MS-CNPrTEOS proved a promising dispersive sorbent and applicable to facile and rapid assay of NSAIDs in water samples.
    Matched MeSH terms: Chromatography, High Pressure Liquid*
  14. Khayoon WS, Saad B, Salleh B, Ismail NA, Abdul Manaf NH, Abdul Latiff A
    Anal Chim Acta, 2010 Oct 29;679(1-2):91-7.
    PMID: 20951862 DOI: 10.1016/j.aca.2010.09.008
    The development of a reversed phase high performance liquid chromatography fluorescence method for the determination of the mycotoxins fumonisin B(1) and fumonisin B(2) by using silica-based monolithic column is described. The samples were first extracted using acetonitrile:water (50:50, v/v) and purified by using a C(18) solid phase extraction-based clean-up column. Then, pre-column derivatization for the analyte using ortho-phthaldialdehyde in the presence of 2-mercaptoethanol was carried out. The developed method involved optimization of mobile phase composition using methanol and phosphate buffer, injection volume, temperature and flow rate. The liquid chromatographic separation was performed using a reversed phase Chromolith(®) RP-18e column (100 mm × 4.6 mm) at 30 °C and eluted with a mobile phase of a mixture of methanol and phosphate buffer pH 3.35 (78:22, v/v) at a flow rate of 1.0 mL min(-1). The fumonisins separation was achieved in about 4 min, compared to approximately 20 min by using a C(18) particle-packed column. The fluorescence excitation and emission were at 335 nm and 440 nm, respectively. The limits of detections were 0.01-0.04 μg g(-1) fumonisin B(1) and fumonisin B(2), respectively. Good recoveries were found for spiked samples (0.1, 0.5, 1.5 μg g(-1) fumonisins B(1) and B(2)), ranging from 84.0 to 106.0% for fumonisin B(1) and from 81.0 to 103.0% for fumonisin B(2). Fifty-three samples were analyzed including 39 food and feeds and 14 inoculated corn and rice. Results show that 12.8% of the food and feed samples were contaminated with fumonisin B(1) (range, 0.01-0.51 μg g(-1)) and fumonisin B(2) (0.05 μg g(-1)). The total fumonisins in these samples however, do not exceed the legal limits established by the European Union of 0.8 μg g(-1). Of the 14 inoculated samples, 57.1% contained fumonisin B(1) (0.16-41.0 μg g(-1)) and fumonisin B(2) (range, 0.22-50.0 μg g(-1)). Positive confirmation of selected samples was carried out using liquid chromatography-tandem mass spectrometry, using triple quadrupole analyzer and operated in the multiple reaction monitoring mode.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
  15. Memon AH, Ismail Z, Aisha AF, Al-Suede FS, Hamil MS, Hashim S, et al.
    PMID: 25530783 DOI: 10.1155/2014/470179
    Syzygium campanulatum Korth is an equatorial, evergreen, aboriginal shrub of Malaysia. Conventionally it has been used as a stomachic. However, in the currently conducted study dimethyl cardamonin or 2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone (DMC) was isolated from S. campanulatum Korth, leaf extract. The structural characterization of DMC was carried out by making use of various techniques including UV, IR, NMR spectral followed by LC-MS, and X-ray crystallographic techniques. For determining the purity of compound, highly effective techniques including TLC, HPLC, and melting point were used. The cytotoxicity of DMC and three different extracts of S. campanulatum was evaluated against human colon cancer cell line (HT-29) by three different assays. DMC and ethanolic extract revealed potent and dose-dependent cytotoxic activity on the cancer cell line with IC50 12.6 and 90.1 µg/mL, respectively. Quite astonishingly to our knowledge, this is the very first report on S. campanulatum as being a rich source (3.5%) of DMC, X-ray crystallography, and anticancer activity on human colon cancer cells.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  16. Mohd Adzim Khalili, R.,, Norhayati, A.H., Rokiah,M. Y., Asmah, R., Siti Muskinah, M., Abdul Manaf, A.
    MyJurnal
    This study was conducted to determine radical scavenging activity and vitamin antioxidant composition in red pitaya from organic plantation. For antioxidant vitamins analysis, a reverse-phase high performance liquid chromatography was used and radical scavenging activity of methanolic and water extract were determined using 1,1-diphenyl-2-pircrylhydrazyl assay. Results for radical scavenging activity, red pitaya methanolic extract achieved the highest percentage 70.13% compared with water extract (47.13%). Antioxidant vitamins composition in red pitaya showed that the concentration of vitamin A is 120.13 ± 0.69 μg/100 g freeze-dried sample, vitamin C is 540.27 ± 0.59 μg/100 g fresh samples and vitamin E is 105.67 ± 0.56 μg/100 g freeze-dried samples. This shows that red pitaya may become an alternative and potential source of natural antioxidant.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  17. Saadi S, Ariffin AA, Ghazali HM, Miskandar MS, Boo HC, Abdulkarim SM
    Food Chem, 2012 May 1;132(1):603-12.
    PMID: 26434338 DOI: 10.1016/j.foodchem.2011.10.095
    The main goal of the present work was to assess the mechanism of crystallisation, more precisely the dominant component responsible for primary crystal formations and fat agglomerations. Therefore, DSC results exhibited significant effect on temperature transition; peak sharpness and enthalpy at palm stearin (PS) levels more than 40wt.%. HPLC data demonstrated slight reduction in the content of POO/OPO at PS levels less than 40wt.%, while the excessive addition of PS more than 40wt.% increased significantly PPO/POP content. The pNMR results showed significant drop in SFC for blends containing PS less than 40wt.%, resulting in low SFC less than 15% at body temperature (37°C). Moreover, the values of viscosity (η) and shear stress (τ) at PS levels over 40wt.% expressed excellent internal friction of the admixtures. All the data reported indicate that PPO/POP was the major component of primary nucleus developed. In part, the levels of PS should be less than 40wt.%, if these blends are designed to be used for margarine production.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods*
  18. Yanty, N.A.M., Marikkar, J.M.N., Abdulkarim, S.M.
    MyJurnal
    A study was carried out to compare the composition and thermal profiles of the fat component of six brands of commercial biscuits (BA, BB, BC, BD, BE & BF) with those of lard and palm oil. Extraction of fat from biscuit samples was done using petroleum ether according to the soxhlet extraction procedure. The isolated fat samples along with lard and palm oil were analyzed using gas liquid chromatography (GLC), reversed-phase high performance liquid chromatography (RP-HPLC), and differential scanning calorimetry (DSC). According to GLC analysis, palm oil, lard and all six biscuit brands had either palmitic or oleic acid as major fatty acids. Sn-2 positional analysis of fatty acids showed that oleic (> 60%) as the most dominant fatty acid of palm oil and biscuit brands BA, BB, BC, and BD while palmitic (> 60%) as the most dominant fatty acid of lard and biscuit brands BE and BF. RP-HPLC analysis showed that the triacylglycerol (TAG) profiles of lard and biscuit brands BE and BF were closely similar while those of brands BA, BB, BC, and BD and palm oil were similar. DSC analysis showed that the cooling and heating profiles of lard and brands BE and BF were similar, while those of palm oil and brands BA, BB, BC, and BD were similar. Hence, this study concluded that biscuit brands BE and BF are not suitable for consumers whose religious restriction prohibit the use of lard as food ingredient.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  19. Azmi NH, Ismail M, Ismail N, Imam MU, Alitheen NB, Abdullah MA
    PMID: 26858770 DOI: 10.1155/2015/153684
    The pathogenesis of Alzheimer's disease involves complex etiological factors, of which the deposition of beta-amyloid (Aβ) protein and oxidative stress have been strongly implicated. We explored the effects of H2O2, which is a precursor for highly reactive hydroxyl radicals, on neurotoxicity and genes related to AD on neuronal cells. Candidate bioactive compounds responsible for the effects were quantified using HPLC-DAD. Additionally, the effects of germinated brown rice (GBR) on the morphology of Aβ(1-42) were assessed by Transmission Electron Microscopy and its regulatory effects on gene expressions were explored. The results showed that GBR extract had several phenolic compounds and γ-oryzanol and altered the structure of Aβ(1-42) suggesting an antiamyloidogenic effect. GBR was also able to attenuate the oxidative effects of H2O2 as implied by reduced LDH release and intracellular ROS generation. Furthermore, gene expression analyses showed that the neuroprotective effects of GBR were partly mediated through transcriptional regulation of multiple genes including Presenilins, APP, BACE1, BACE2, ADAM10, Neprilysin, and LRP1. Our findings showed that GBR exhibited neuroprotective properties via transcriptional regulation of APP metabolism with potential impact on Aβ aggregation. These findings can have important implications for the management of neurodegenerative diseases like AD and are worth exploring further.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  20. Agustian J, Kamaruddin AH, Aboul-Enein HY
    Chirality, 2012 May;24(5):356-67.
    PMID: 22517322 DOI: 10.1002/chir.22019
    Because chiral liquid chromatography (LC) could become a powerful tool to estimate racemic atenolol quantity, excellent enantiomeric separation should be produced during data acquisition for satisfactory observation of atenolol concentrations throughout the racemic resolution processes. Selection of chiral LC column and analytical protocol that fulfill demands of the ultra fast LC analysis is essential. This article describes the characteristics of atenolol chromatographic separation that resulted from different resolution media and analytical protocols with the use of a Chiralcel® OD column. The chromatograms showed quite different characteristics of the separation process. The single enantiomer and racemic atenolol could be recognized by the Chiralcel® OD column in less than 20 min. Symmetrical peaks were obtained; however, several protocols produced peaks with wide bases and slanted baselines. Observations showed that efficient enantioresolution of racemic atenolol was obtained at slow mobile phase flow rate, decreased concentration of amine-type modifier but increased alcohol content in mobile phase and highest ultraviolet detection wavelength were required. The optimal ultra fast LC protocol enables to reduce and eliminate the peaks of either the atenolol solvent or the buffers and provided the highest peak intensities of both atenolol enantiomers.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
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