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  1. Analysis of Terpenoid Indole Alkaloids, Carotenoids, Phytosterols, and NMR-Based Metabolomics for Catharanthus roseus Cell Suspension Cultures
    Saiman MZ, Mustafa NR, Verpoorte R
    Methods Mol Biol, 2018;1815:437-455.
    PMID: 29981141 DOI: 10.1007/978-1-4939-8594-4_31
    The plant Catharanthus roseus is a rich source of terpenoid indole alkaloids (TIA). Some of the TIA are important as antihypertensive (ajmalicine) and anticancer (vinblastine and vincristine) drugs. However, production of the latter is very low in the plant. Therefore, in vitro plant cell cultures have been considered as a potential supply of these chemicals or their precursors. Some monomeric alkaloids can be produced by plant cell cultures, but not on a level feasible for commercialization, despite extensive studies on this plant that deepened the understanding of the TIA biosynthesis and its regulation. In order to analyze the metabolites in C. roseus cell cultures, this chapter presents the method of TIA, carotenoids, and phytosterols analyses. Furthermore, an NMR-based metabolomics approach to study C. roseus cell culture is described.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  2. Fulltext Optimization of process parameters in preparation of tocotrienol-rich red palm oil-based nanoemulsion stabilized by Tween80-Span 80 using response surface methodology
    Chong WT, Tan CP, Cheah YK, B Lajis AF, Habi Mat Dian NL, Kanagaratnam S, et al.
    PLoS One, 2018;13(8):e0202771.
    PMID: 30142164 DOI: 10.1371/journal.pone.0202771
    Red palm oil (RPO) is a natural source of Vitamin E (70-80% tocotrienol). It is a potent natural antioxidant that can be used in skin-care products. Its antioxidant property protects skin from inflammation and aging. In our work, a tocotrienol-rich RPO-based nanoemulsion formulation was optimized using response surface methodology (RSM) and formulated using high pressure homogenizer. Effect of the concentration of three independent variables [surfactant (5-15 wt%), co-solvent (10-30 wt%) and homogenization pressure (500-700 bar)] toward two response variables (droplet size, polydispersity index) was studied using central composite design (CCD) coupled to RSM. RSM analysis showed that the experimental data could be fitted into a second-order polynomial model and the coefficients of multiple determination (R2) is 0.9115. The optimized formulation of RPO-based nanoemulsion consisted of 6.09 wt% mixed surfactant [Tween 80/Span 80 (63:37, wt)], 20 wt% glycerol as a co-solvent via homogenization pressure (500 bar). The optimized tocotrienol-rich RPO-based nanoemulsion response values for droplet size and polydispersity index were 119.49nm and 0.286, respectively. The actual values of the formulated nanoemulsion were in good agreement with the predicted values obtained from RSM, thus the optimized compositions have the potential to be used as a nanoemulsion for cosmetic formulations.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  3. Thiol-functionalized magnetic carbon nanotubes for magnetic micro-solid phase extraction of sulfonamide antibiotics from milks and commercial chicken meat products
    Nasir ANM, Yahaya N, Zain NNM, Lim V, Kamaruzaman S, Saad B, et al.
    Food Chem, 2019 Mar 15;276:458-466.
    PMID: 30409620 DOI: 10.1016/j.foodchem.2018.10.044
    Thiol-functionalized magnetic carbon nanotubes (TMCNTs) were employed as the sorbent in the magnetic micro-solid phase extraction (M-µ-SPE) of sulfonamide antibiotics (SAs) in water, milks and chicken meat products prior to high performance liquid chromatography-diode array detector (HPLC-DAD) analysis. The synthesized sorbent was characterized by several spectroscopic techniques. Optimum conditions were: 20 mg of TMCNTs at pH 4, 2 min extraction time, 10% addition of salt and 30 mL of sample volume. Under the optimized TMCNTs-M-µ-SPE and HPLC-DAD conditions, the method showed good linearity in the range of 0.1-500 µg L-1 (r2 ≥ 0.9950), low limits of detection (0.02-1.5 µg L-1), good analytes recovery (80.7-116.2%) and acceptable RSDs (0.3-7.7%, n = 15). The method was applied to tap water (1), milks (15) and commercial chicken meat products (35), SAs were detected in five chicken meat samples (3.0-25.7 µg L-1). The method is critically compared to those reported in the literature.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  4. Fulltext The major allergen Der p 2 is a cholesterol binding protein
    Reginald K, Chew FT
    Sci Rep, 2019 02 07;9(1):1556.
    PMID: 30733527 DOI: 10.1038/s41598-018-38313-9
    Der p 2 is a major dust mite allergen and >80% of mite allergic individuals have specific IgE to this allergen. Although it is well characterized in terms of allergenicity, there is still some ambiguity in terms of its biological function. Three-dimensional structural analysis of Der p 2 and its close homologues indicate the presence of a hydrophobic cavity which can potentially bind to lipid molecules. In this study, we aimed to identify the potential ligand of Der p 2. Using a liposome pulldown assay, we show that recombinant Der p 2 binds to liposomes prepared with exogenous cholesterol in a dose dependent fashion. Next, an ELISA based assay using immobilized lipids was used to study binding specificities of other lipid molecules. Cholesterol was the preferred ligand of Der p 2 among 11 different lipids tested. Two homologues of Der p 2, Der f 2 and Der f 22 also bound to cholesterol. Further, using liquid chromatography-mass spectrometry (LC-MS), we confirmed that cholesterol is the natural ligand of Der p 2. Three amino acid residues of Der p 2, V104, V106 and V110 are possible cholesterol binding sites, as alanine mutations of these residues showed a significant decrease in binding (p 
    Matched MeSH terms: Chromatography, High Pressure Liquid
  5. In-vitro inhibitory effect of Tualang honey on cytochrome P450 2C8 activity
    Muthiah YD, Ong CE, Sulaiman SA, Tan SC, Ismail R
    J Pharm Pharmacol, 2012 Dec;64(12):1761-9.
    PMID: 23146039 DOI: 10.1111/j.2042-7158.2012.01551.x
    To investigate the effect of Tualang honey on cytochrome P450 2C8 (CYP2C8) activity in vitro using an amodiaquine N-desethylase assay.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  6. Identification of potential serum metabolic biomarkers for patient with keratoconus using untargeted metabolomics approach
    Daphne Teh AL, Jayapalan JJ, Loke MF, Wan Abdul Kadir AJ, Subrayan V
    Exp Eye Res, 2021 10;211:108734.
    PMID: 34428458 DOI: 10.1016/j.exer.2021.108734
    This study aimed to investigate the metabolite differences between patients with keratoconus and control subjects and identify potential serum biomarkers for keratoconus using a non-targeted metabolomics approach. Venous blood samples were obtained from patients with keratoconus (n = 20) as well as from age-, gender- and race-matched control subjects (n = 20). Metabolites extracted from serum were separated and analyzed by liquid chromatography/quadrupole time-of-flight mass spectrometer. Processing of raw data and analysis of the data files was performed using Agilent Mass Hunter Qualitative software. The identified metabolites were subjected to a principal component and hierarchical cluster analysis. Appropriate statistical tests were used to analyze the metabolomic profiling data. Together, the analysis revealed that the dehydroepiandrosterone sulfate from the steroidal hormone synthesis pathway was significantly upregulated in patients with keratoconus (p 
    Matched MeSH terms: Chromatography, High Pressure Liquid
  7. Fulltext Enhancing recovery of bioactive compounds from Cosmos caudatus leaves via ultrasonic extraction
    Latiff NA, Ong PY, Abd Rashid SNA, Abdullah LC, Mohd Amin NA, Fauzi NAM
    Sci Rep, 2021 08 27;11(1):17297.
    PMID: 34453075 DOI: 10.1038/s41598-021-96623-x
    Cosmos caudatus (C. caudatus) is a medicinal plant that is high in bioactive compounds such as phenolics. In this study, an ultrasound extraction method was used to optimise the extraction of bioactive compounds from C. caudatus leaves. Response surface methodology (RSM) based on a Box-Behnken design (BBD) was applied to obtain the optimum extraction parameters which is solid-liquid ratio (10-30 g/mL), particle size (180-850 µm) and extraction time (20-30 min) for maximal quercitrin and total phenolic content (TPC) yields. Analysis of antimicrobial activity was performed against two human pathogenic microbes: Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) by the agar well diffusion method. The optimal ultrasonic extraction condition was as follow: solvent-liquid ratio of 1:28 (g/mL), particle size of 485 µm, and duration of 30 min, respectively. Remarkably, extraction using ultrasonic method had recovered more bioactive content and antioxidant activity than the Soxhlet method. The extract also exhibited good antimicrobial activities. Due to the above findings, the ultrasonic extraction was found to be suitable to improve recovery extraction of quercitrin and TPC from C. caudatus leaves. It also opens the possibility that the plant extract can be used for functional food and antimicrobial agents in various applications.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  8. Validation of an enzyme-linked immunosorbent assay screening method and a liquid chromatography-tandem mass spectrometry confirmation method for the identification and quantification of ketamine and norketamine in urine samples from Malaysia
    Harun N, Anderson RA, Miller EI
    J Anal Toxicol, 2009 8 6;33(6):310-21.
    PMID: 19653934 DOI: 10.1093/jat/33.6.310
    An ELISA and a liquid chromatography-tandem mass spectrometry (LC-MS-MS) confirmation method were developed and validated for the identification and quantitation of ketamine and its major metabolite norketamine in urine samples. The Neogen ketamine microplate ELISA was optimized with respect to sample and enzyme conjugate volumes and the sample preincubation time before addition of the enzyme conjugate. The ELISA kit was validated to include an assessment of the dose-response curve, intra- and interday precision, limit of detection (LOD), and cross-reactivity. The sensitivity and specificity were calculated by comparison to the results from the validated LC-MS-MS confirmation method. An LC-MS-MS method was developed and validated with respect to LOD, lower limit of quantitation (LLOQ), linearity, recovery, intra- and interday precision, and matrix effects. The ELISA dose-response curve was a typical S-shaped binding curve, with a linear portion of the graph observed between 25 and 500 ng/mL for ketamine. The cross-reactivity of 200 ng/mL norketamine to ketamine was 2.1%, and no cross-reactivity was detected with 13 common drugs tested at 10,000 ng/mL. The ELISA LOD was calculated to be 5 ng/mL. Both intra- (n = 10) and interday (n = 50) precisions were below 5.0% at 25 ng/mL. The LOD for ketamine and norketamine was calculated statistically to be 0.6 ng/mL. The LLOQ values were also calculated statistically and were 1.9 ng/mL and 2.1 ng/mL for ketamine and norketamine, respectively. The test linearity was 0-1200 ng/mL with correlation coefficient (R(2)) > 0.99 for both analytes. Recoveries at 50, 500, and 1000 ng/mL range from 97.9% to 113.3%. Intra- (n = 5) and interday (n = 25) precisions between extracts for ketamine and norketamine were excellent (< 10%). Matrix effects analysis showed an average ion suppression of 5.7% for ketamine and an average ion enhancement of 13.0% for norketamine for urine samples collected from six individuals. A comparison of ELISA and LC-MS-MS results demonstrated a sensitivity, specificity, and efficiency of 100%. These results indicated that a cutoff value of 25 ng/mL ketamine in the ELISA screen is particularly suitable and reliable for urine testing in a forensic toxicology setting. Furthermore, both ketamine and norketamine were detected in all 34 urine samples collected from individuals socializing in pubs by the Royal Malaysian Police. Ketamine concentrations detected by LC-MS-MS ranged from 22 to 31,670 ng/mL, and norketamine concentrations ranged from 25 to 10,990 ng/mL. The concentrations of ketamine and norketamine detected in the samples are most ikely indicative of ketamine abuse.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  9. Comparative bioavailability study of two controlled-release pentoxifylline tablet preparations
    Yuen KH, Wong JW, Peh KK, Julianto T, Choy WP
    Drug Dev Ind Pharm, 2000 Jul;26(7):803-7.
    PMID: 10872103
    The bioavailability of a generic preparation of pentoxifylline sustained-release (SR) tablet was evaluated in comparison with a proprietary product (Trental 400). For the study, 12 healthy male volunteers participated; the study was conducted according to a randomized, two-way crossover design. The bioavailability was compared using the parameters total area under the plasma level-time curve AUC0-infinity, peak plasma concentration Cmax, and time to reach peak plasma concentration Tmax. No statistically significant difference was observed between the values of the two products in all three parameters. The 90% confidence interval for the ratio of the logarithmic transformed AUC0-infinity values of the generic pentoxifylline over those of Trental 400 was found to lie between 0.83 and 1.00, while that of the parameter Cmax was between 0.91 and 1.29. In addition, elimination half-life t1/2 and apparent volume of distribution Vd were calculated. There was no statistically significant difference between the t1/2 Vd values obtained from the data of the two preparations.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  10. The production and characterisation of trichotoxin peptaibols, by Trichoderma asperellum
    Chutrakul C, Alcocer M, Bailey K, Peberdy JF
    Chem Biodivers, 2008 Sep;5(9):1694-706.
    PMID: 18816522 DOI: 10.1002/cbdv.200890158
    Trichoderma spp. are regularly found as a constituent of the mycoflora of many soils and are noted for their antagonistic activity against bacteria and other fungi. This latter property is the basis for the widespread interest in their use in the biological control of soil-borne fungal plant pathogens. This antagonism is partly based on their ability to produce an impressive inventory of secondary metabolites. An important group of bioactive metabolites produced by Trichoderma spp. are the non-ribosomal peptides (NRPs), especially the peptaibols. A virulent antagonistic strain, T. asperellum, which had been used in biological control strategies in Malaysia and previously examined for mycolytic enzyme production, has been studied for its potential for peptaibol production. The present research demonstrated the ability of T. asperellum to produce at least two metabolites which were identified as acid trichotoxin 1704E (Ac-Aib-Gly-Aib-Leu-Aib-Gln-Aib-Aib-Aib-Ala-Ala-Aib-Pro-Leu-Aib-Iva-Glu-Vol) and neutral trichotoxin 1717A (Ac-Aib-Gly-Aib-Leu-Aib-Gln-Aib-Aib-Aib-Ala-Aib-Aib-Pro-Leu-Aib-Iva-Gln-Vol). Addition of free Aib to the culture medium enhanced the production of trichotoxins. Biological activity of these substances was investigated against Bacillus stearothermophilus. The general characteristics of peptaibols, also found in the trichotoxins, include the presence of high proportions of the uncommon amino acid Aib, the protection of the N- and C-termini by an acetyl group and reduction of the C-terminus to 2-amino alcohols, respectively, amphipathy and microheterogeneity.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  11. Development and formulation of Moringa oleifera standardised leaf extract film dressing for wound healing application
    Chin CY, Jalil J, Ng PY, Ng SF
    J Ethnopharmacol, 2018 Feb 15;212:188-199.
    PMID: 29080829 DOI: 10.1016/j.jep.2017.10.016
    ETHNOPHARMACOLOGICAL RELEVANCE: M.oleifera is a medicinal plant traditionally used for skin sores, sore throat and eye infections. Recently, the wound healing property of the leaves of M. oleifera was has been well demonstrated experimentally in both in vivo and in vitro models. However, there is a lack of research which focuses on formulating M.oleifera into a functional wound dressing. In this study, the M.oleifera leaf standardized aqueous extract with highest potency in vitro migration was formulated into a film for wound healing application.

    MATERIALS AND METHODS: Firstly, M. oleifera leaf were extracted in various solvents (aqueous, 50%, 70% and 100% ethanolic extracts) and standardized by reference standards using UHPLC technique. The extracts were then tested for cell migration and proliferation using HDF and HEK cell lines. M. oleifera leaf aqueous extract was then incorporated into alginate-pectin (SA-PC) based film dressing. The film dressings were characterized for the physicochemical properties and the bioactives release from the M. oleifera leaf extract loaded film dressing was also investigated using Franz diffusion cells.

    RESULTS: All extracts were found to contain vicenin-2, chlorogenic acid, gallic acid, quercetin, kaempferol, rosmarinic acid and rutin. Among all M. oleifera extracts, aqueous standardized leaf extracts showed the highest human dermal fibroblast and human keratinocytes cells proliferation and migration properties. Among the film formulations, SA-PC (3% w/v) composite film dressing containing M. oleifera aqueous leaf extract was found to possess optimal physicochemical properties as wound dressing.

    CONCLUSION: A potentially applicable wound dressing formulated as an alginate-pectin film containing aqueous extracts of M. oleifera has been developed. The dressing would be suitable for wounds with moderate exudates.

    Matched MeSH terms: Chromatography, High Pressure Liquid
  12. Inhibition of CYP3A by Antimalarial Piperaquine and Its Metabolites in Human Liver Microsomes With IVIV Extrapolation
    Aziz MY, Hoffmann KJ, Ashton M
    J Pharm Sci, 2018 05;107(5):1461-1467.
    PMID: 29352982 DOI: 10.1016/j.xphs.2018.01.009
    The potential of the antimalarial piperaquine and its metabolites to inhibit CYP3A was investigated in pooled human liver microsomes. CYP3A activity was measured by liquid chromatography-tandem mass spectrometry as the rate of 1'-hydroxymidazolam formation. Piperaquine was found to be a reversible, potent inhibitor of CYP3A with the following parameter estimates (%CV): IC50 = 0.76 μM (29), Ki = 0.68 μM (29). In addition, piperaquine acted as a time-dependent inhibitor with IC50 declining to 0.32 μM (28) during 30-min pre-incubation. Time-dependent inhibitor estimates were kinact = 0.024 min-1 (30) and KI = 1.63 μM (17). Metabolite M2 was a highly potent reversible inhibitor with estimated IC50 and Ki values of 0.057 μM (17) and 0.043 μM (3), respectively. M1 and M5 metabolites did not show any inhibitory properties within the limits of assay used. Average (95th percentile) simulated in vivo areas under the curve of midazolam increased 2.2-fold (3.7-fold) on the third which is the last day of piperaquine dosing, whereas for its metabolite M2, areas under the curve of midazolam increased 7.7-fold (13-fold).
    Matched MeSH terms: Chromatography, High Pressure Liquid
  13. Monoclonal antibody-based enzyme immunoassay for detection of porcine plasma in fish surimi
    Raja Nhari RMH, Khairil Mokhtar NF, Hanish I, Hamid M, Mohamed Rashidi MAA, Shahidan NM
    Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2018 May;35(5):807-817.
    PMID: 29285986 DOI: 10.1080/19440049.2017.1420920
    Detection of porcine plasma using indirect ELISA was developed using mAb B4E1 for the prevention of their usage in human food that creates religious and health conflicts. The immunoassay has a CV liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed the 60-kDa protein to be porcine serum albumin.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  14. Fulltext Reheating of soy oil is detrimental to bone metabolism in oestrogen deficient rats
    Ima-Nirwana S, Ahmad SN, Yee LJ, Loh HC, Yew SF, Norazlina M, et al.
    Singapore Med J, 2007 Mar;48(3):200-6.
    PMID: 17342287
    The short-term and long- term effects of heated soy oil on bone metabolism in ovariectomised Sprague-Dawley rats were studied.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  15. Fulltext Phenolics and flavonoids compounds, phenylanine ammonia lyase and antioxidant activity responses to elevated CO₂ in Labisia pumila (Myrisinaceae)
    Jaafar HZ, Ibrahim MH, Karimi E
    Molecules, 2012 May 25;17(6):6331-47.
    PMID: 22634843 DOI: 10.3390/molecules17066331
    A split plot 3 × 3 experiment was designed to examine the impact of three concentrations of CO₂ (400, 800 and 1,200 μmol·mol⁻¹) on the phenolic and flavonoid compound profiles, phenylalanine ammonia lyase (PAL) and antioxidant activity in three varieties of Labisia pumila Benth. (var. alata, pumila and lanceolata) after 15 weeks of exposure. HPLC analysis revealed a strong influence of increased CO₂ concentration on the modification of phenolic and flavonoid profiles, whose intensity depended on the interaction between CO₂ levels and L. pumila varieties. Gallic acid and quercetin were the most abundant phenolics and flavonoids commonly present in all the varieties. With elevated CO₂ (1,200 μmol·mol⁻¹) exposure, gallic acid increased tremendously, especially in var. alata and pumila (101-111%), whilst a large quercetin increase was noted in var. lanceolata (260%), followed closely by alata (201%). Kaempferol, although detected under ambient CO₂ conditions, was undetected in all varieties after exposure. Instead, caffeic acid was enhanced tremendously in var. alata (338~1,100%) and pumila (298~433%). Meanwhile, pyragallol and rutin were only seen in var. alata (810 μg·g⁻¹ DW) and pumila (25 μg·g⁻¹ DW), respectively, under ambient conditions; but the former compound went undetected in all varieties while rutin continued to increase by 262% after CO₂ enrichment. Interestingly, naringenin that was present in all varieties under ambient conditions went undetected under enrichment, except for var. pumila where it was enhanced by 1,100%. PAL activity, DPPH and FRAP also increased with increasing CO₂ levels implying the possible improvement of health-promoting quality of Malaysian L. pumila under high CO₂ enrichment conditions.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  16. Fulltext Co-Solvent Selection for Supercritical Fluid Extraction (SFE) of Phenolic Compounds from Labisia pumila
    Radzali SA, Markom M, Saleh NM
    Molecules, 2020 Dec 11;25(24).
    PMID: 33322389 DOI: 10.3390/molecules25245859
    A preliminary study was conducted to study the effects of different types and concentrations of co-solvents based on yield, composition and antioxidants capacity of extract prior to optimization studies of supercritical fluid extraction (SFE) of Labisia pumila (locally referred to as 'kacip fatimah'). The following co-solvents were studied prior to the optimization of supercritical carbon dioxide (SC-CO2) technique: ethanol, water, methanol, as well as aqueous solutions of ethanol-water and methanol-water (50% and 70% v/v). By using the selected co-solvents, identification of phenolic acids (gallic acid, methyl gallate and caffeic acid) was determined by using High-Performance Liquid Chromatography (HPLC). Then, the antioxidant capacity was evaluated by using three different assays: total phenolic content (TPC), ferric reducing/antioxidant power (FRAP) and free radical-scavenging capacity of 2,2-diphenyl-1-picrylhydrazyl (DPPH). SC-CO2 with 70% ethanol-water co-solvent was superior in terms of a higher combination of phenolic compounds extracted and antioxidants capacity. Overall, SC-CO2 with co-solvent 70% ethanol-water technique was efficient in extracting phenolic compounds from L. pumila, and thus the usage of this solvent system should be considered for further optimization studies.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  17. Fulltext The characterisation of an alkali-stable maltogenic amylase from Bacillus lehensis G1 and improved malto-oligosaccharide production by hydrolysis suppression
    Abdul Manas NH, Pachelles S, Mahadi NM, Illias RM
    PLoS One, 2014;9(9):e106481.
    PMID: 25221964 DOI: 10.1371/journal.pone.0106481
    A maltogenic amylase (MAG1) from alkaliphilic Bacillus lehensis G1 was cloned, expressed in Escherichia coli, purified and characterised for its hydrolysis and transglycosylation properties. The enzyme exhibited high stability at pH values from 7.0 to 10.0. The hydrolysis of β-cyclodextrin (β-CD) produced malto-oligosaccharides of various lengths. In addition to hydrolysis, MAG1 also demonstrated transglycosylation activity for the synthesis of longer malto-oligosaccharides. The thermodynamic equilibrium of the multiple reactions was shifted towards synthesis when the reaction conditions were optimised and the water activity was suppressed, which resulted in a yield of 38% transglycosylation products consisting of malto-oligosaccharides of various lengths. Thin layer chromatography and high-performance liquid chromatography analyses revealed the presence of malto-oligosaccharides with a higher degree of polymerisation than maltoheptaose, which has never been reported for other maltogenic amylases. The addition of organic solvents into the reaction further suppressed the water activity. The increase in the transglycosylation-to-hydrolysis ratio from 1.29 to 2.15 and the increased specificity toward maltopentaose production demonstrated the enhanced synthetic property of the enzyme. The high transglycosylation activity of maltogenic amylase offers a great advantage for synthesising malto-oligosaccharides and rare carbohydrates.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  18. Fulltext Haemoglobin A1c: comparing performance of two point of care devices with laboratory analyser
    Wan Mohd Zin RM, Ahmad Kamil ZI, Tuan Soh TR, Embong M, Wan Mohamud WN
    BMC Res Notes, 2013 Dec 18;6:540.
    PMID: 24344903 DOI: 10.1186/1756-0500-6-540
    BACKGROUND: Measurement of HbA1c has been widely used for long-term monitoring and management of diabetes control. There is increasing use of point-of-care (POC) devices for measuring HbA1c where quicker results would allow immediate clinical management decisions to be made. Therefore, it is important to evaluate and compare the performance of such devices to the reference laboratory method.

    FINDINGS: A total of 274 venous blood was collected from normal healthy adults during the community screening programmes. The performance of POC devices, Afinion and Quo-test were compared to central laboratory HPLC method; Adams A1c HA 8160. Both POC devices showed good correlation to HA 8160 with r = 0.94 (p < 0.001) and r = 0.95 (p < 0.001) for Afinion and Quo-test respectively. The means difference were statistically higher between POC and HA 8160 with 0.23% (95% CI 0.19-0.26, p < 0.001) and 0.29% (95% CI 0.24-0.34, p < 0.001) for Afinion and Quo-test respectively.

    CONCLUSIONS: Both POC devices could be considered in health clinics for diabetes management but not to be used for the diagnostic purposes.

    Matched MeSH terms: Chromatography, High Pressure Liquid
  19. A new high-performance thin-layer chromatographic method for determining bile salt hydrolase activity
    Rohawi NS, Ramasamy K, Agatonovic-Kustrin S, Lim SM
    J Chromatogr B Analyt Technol Biomed Life Sci, 2018 Aug 15;1092:145-151.
    PMID: 29894935 DOI: 10.1016/j.jchromb.2018.06.009
    A quantitative assay using high-performance thin-layer chromatography (HPTLC) was developed to investigate bile salt hydrolase (BSH) activity in Pediococcus pentosaceus LAB6 and Lactobacillus plantarum LAB12 probiotic bacteria isolated from Malaysian fermented food. Lactic acid bacteria (LAB) were cultured in de Man Rogosa and Sharpe (MRS) broth containing 1 mmol/L of sodium-based glyco- and tauro-conjugated bile salts for 24 h. The cultures were centrifuged and the resultant cell free supernatant was subjected to chromatographic separation on a HPTLC plate. Conjugated bile salts were quantified by densitometric scans at 550 nm and results were compared to digital image analysis of chromatographic plates after derivatisation with anisaldehyde/sulfuric acid. Standard curves for bile salts determination with both methods show good linearity with high coefficient of determination (R2) between 0.97 and 0.99. Method validation indicates good sensitivity with low relative standard deviation (RSD) (<10%), low limits of detection (LOD) of 0.4 versus 0.2 μg and limit of quantification (LOQ) of 1.4 versus 0.7 μg, for densitometric vs digital image analysis method, respectively. The bile salt hydrolase activity was found to be higher against glyco- than tauro-conjugated bile salts (LAB6; 100% vs >38%: LAB12; 100% vs >75%). The present findings strongly show that quantitative analysis via digitally-enhanced HPTLC offers a rapid quantitative analysis for deconjugation of bile salts by probiotics.
    Matched MeSH terms: Chromatography, High Pressure Liquid
  20. Phytoconstituents of Endiandra kingiana; antidiabetic effects and molecular docking studies on alpha-amylase and alpha-glucosidase
    Tanazi NNH, Aziz AN, Azmi MN, Abu Bakar MH, Hassim MFN, Wahab NHA, et al.
    Nat Prod Res, 2024 Dec;38(24):4375-4382.
    PMID: 38009213 DOI: 10.1080/14786419.2023.2283759
    Phytochemical investigation on the bark of E. kingiana plant afforded ten compounds, including six polyketides namely kingianin A 1, kingianin B 2, kingianin E 3, kingianin F 4, kingianin K 5 and kingianin L 6, three endiandric acids; kingianic acid A 7, tsangibeilin B 8 and endiandric acid M 9, and one sesquiterpene; daibuoxide 10. All compounds were separated as racemic mixture by recycling high-performance liquid chromatography (RHPLC), except for daibuoxide. Their structures were elucidated by detailed spectroscopic and comparative literature data analysis. This is the first report on the presence of the sesquiterpene; daibuoxide in Endiandra genus. In vitro enzymatic bio-evaluation of the isolated compounds against α-amylase and α-glucosidase showed that 4 demonstrated the best α-amylase and α-glucosidase inhibitory activity with IC50 values of 181.54 ± 6.27 µg/mL and 237.87 ± 0.07 µg/mL, respectively. In addition, molecular docking analysis confirmed the α-amylase and α-glucosidase inhibitory activities demonstrated by 4.
    Matched MeSH terms: Chromatography, High Pressure Liquid
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