Displaying publications 1 - 20 of 151 in total

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  1. Phytochemical quantification and HPLC analysis of Parkia speciosa pod extract
    Cheong NDH, Mohamed E, Haron N, Camalxaman SN, Abdullah A, Mohamad Yusof MI, et al.
    Med J Malaysia, 2024 Mar;79(Suppl 1):34-39.
    PMID: 38555883
    INTRODUCTION: Parkia speciosa Hassk., commonly known as bitter bean or twisted cluster bean, is a tropical leguminous plant species native to Southeast Asia. The plant's edible pods have been traditionally used in various cuisines, particularly in Malaysian, Thai, and Indonesian cooking. Apart from being used as a food ingredient, the pods of P. speciosa also have a range of potential applications in other fields, including medicine, agriculture, and industry. The pods are said to have several phytochemicals that hold great therapeutic values such as reducing inflammation, improving digestion, and lowering blood sugar levels. However, there is limited information on the specific phytochemical contents of the pods in the literature. Thus, the aim of this study is to quantify the total phenolic and flavonoid compounds and to determine the concentrations of four selected phytochemical compounds in the P. speciosa pod extract (PSPE).

    MATERIALS AND METHODS: Quantification of the total phenolic (TPC) and flavonoid contents (TFC) in PSPE were done via colourimetric methods; and the determination of the concentrations of four specific phytochemicals (gallic acid, caffeic acid, rutin, and quercetin) were done via High- Performance Liquid Chromatography (HPLC).

    RESULTS: Colourimetric determination of PSPE showed TPC and TFC values of 84.53±9.40 mg GAE/g and 11.96±4.51 mg QE/g, respectively. Additional analysis of the phytochemicals using HPLC revealed that there were 6.45±3.36 g/kg, 5.91±1.07 g/kg, 0.39±0.84 g/kg, and 0.19±0.47 g/kg of caffeic acid, gallic acid, rutin, and quercetin, respectively.

    CONCLUSION: The findings show that PSPE contains substantial amounts of caffeic acid, gallic acid, rutin, and quercetin, which may indicate its potential as antibacterial, anti-inflammatory, anti-lipid, and antiviral medicines.

    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
  2. High performance liquid chromatographic method optimized by Box-Behnken design model to determine caffeine in pharmaceutical preparations and urine samples
    Najmul Hejaz Azmi S, Aqib Nasir Al Rawahi W, Ibrahim Al Yahyai A, Ali Al Qasimi A, Saif Al Fuliti K, Said Al Qalhati O, et al.
    J Chromatogr B Analyt Technol Biomed Life Sci, 2024 Feb 15;1234:124035.
    PMID: 38309045 DOI: 10.1016/j.jchromb.2024.124035
    A UV-HPLC method optimized by Box-Behnken design model was developed to determine caffeine in pharmaceutical preparations and urine samples. The chromatographic conditions followed were mobile phase: methanol/water/ citrate buffer (pH 4.6) (40:25:35, v/v/v),AcclaimTMDionex C18 column (ODS 100A˚, 5 µm; 4.6 × 250 mm),flow rate (0.9 mL min-1), column temperature (30 °C) and UV-detection wavelength (204 nm). The chromatographic variables: pH (A), % methanol fraction (B), flow rate(C) and column temperature (D) were optimized at 50 μg mL-1caffeine using BBD model. The chromatogram resulted in the asymmetry factor (1.23), theoretical plate 13,786 and retention time (5.79 min). The proposed HPLC method's greenness point was assessed byAnalytical Eco-scale and found to be 78 (as per guidelines, ranked as excellent). The linearity was ranged from2.0 to 70 µg mL-1 with coefficient of correlation (r = 0.999) and detection limit of 0.19 µg mL-1. The proposedmethod was developed successfully and applied for the assay of active caffeine in pharmaceutical preparations and urine samples. The % recovery obtained by both (proposed and reference) methods ranged from 99.98 to 100.05 % followed the compliance (100 ± 2 %) with Canadian Health Protection regulatory guidelines. The performance of the proposed method was compared with published papers and found to be acceptable and superior. The proposed method was quite effective as the reference method, and hence can be used as an alternative method for the assay of active caffeine in pharmaceutical preparations and urine samples.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
  3. Characterization and determination of casein glycomacropeptide in dairy products by UHPLC-MS/MS based on its characteristic peptide
    Chen Q, Lai S, Dong L, Liu Y, Pan D, Wu Z, et al.
    Food Chem, 2024 Jan 01;430:137049.
    PMID: 37544157 DOI: 10.1016/j.foodchem.2023.137049
    The ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS) method was built to quantify the casein glycomacropeptide (CGMP) in bovine dairy products accurately based on targeted proteomics. Qualitative analysis of theoretical peptides was carried out using high-resolution mass spectrometry (HRMS) and protein software. Isotope-labeled characteristic peptides were acquired via the labeled amino acid condensation method to correct the matrix effects. Peptide MAIPPK was the representative characteristic peptide for distinguishing the CGMP from κ-casein through trypsin digestion. After optimizing the pre-treatment conditions, the final 8% oxidant concentration was selected and the 10% formic acid concentration with 2.5 h oxidation time. Moreover, the results of methodological verification showed that the recovery rate was 103.7%, meanwhile the precision of inter-day and intra-day was less than 5%. In conclusion, the research demonstrated the characteristic peptide MAIPPK could quantitatively applied to detect CGMP in dairy products.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
  4. Fulltext Stability of glycated haemoglobin (HbA1c) measurements from whole blood samples kept at -196°C for seven to eight years in The Malaysian Cohort study
    Abdullah N, Goh YX, Othman R, Ismail N, Jalal N, Wan Sallam WAF, et al.
    J Clin Lab Anal, 2023 Apr;37(8):e24898.
    PMID: 37243371 DOI: 10.1002/jcla.24898
    OBJECTIVE: Glycated haemoglobin (HbA1c) is a standard indication for screening type 2 diabetes that also has been widely used in large-scale epidemiological studies. However, its long-term quality (in terms of reproducibility) stored in liquid nitrogen is still unknown. This study is aimed to evaluate the stability and reproducibility of HbA1c measurements from frozen whole blood samples kept at -196°C for more than 7 years.

    METHODS: A total of 401 whole blood samples with a fresh HbA1c measurement were randomly selected from The Malaysian Cohort's (TMC) biobank. The HbA1c measurements of fresh and frozen (stored for 7-8 years) samples were assayed using different high-performance liquid chromatography (HPLC) systems. The HbA1c values of the fresh samples were then calculated and corrected according to the later system. The reproducibility of HbA1c measurements between calculated-fresh and frozen samples was assessed using a Passing-Bablok linear regression model. The Bland-Altman plot was then used to evaluate the concordance of HbA1c values.

    RESULTS: The different HPLC systems highly correlated (r = 0.99) and agreed (ICC = 0.96) with each other. Furthermore, the HbA1c measurements for frozen samples strongly correlate with the corrected HbA1c values of the fresh samples (r = 0.875) with a mean difference of -0.02 (SD: -0.38 to 0.38). Although the mean difference is small, discrepancies were observed within the diabetic and non-diabetic samples.

    CONCLUSION: These data demonstrate that the HbA1c measurements between fresh and frozen samples are highly correlated and reproducible.

    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
  5. Determination of biogenic amines in chicken, beef, and mutton by dansyl chloride microwave derivatization in Malaysia
    Yue CS, Lim AK, Chia ML, Wong PY, Chin JSR, Wong WH
    J Food Sci, 2023 Feb;88(2):650-665.
    PMID: 36624628 DOI: 10.1111/1750-3841.16404
    In this study, an improved dansyl-chloride derivatization technique using a microwave synthesizer was used for the qualitative and quantitative analyses of biogenic amine in the fresh meat samples. The derivatization technique was optimized in terms of temperature, reaction time, and spinning speed. The derivatization method together with a validated reversed-phase HPLC-DAD method was used for the determination of biogenic amines in chicken, beef, and mutton sold in the wet market. The results of the analyses showed that tryptamine, putrescine, and histamine were generally detected in all the three types of meat. Higher levels of histamine were found in chicken and beef. However, low levels of histamine were observed in mutton. Tyramine was either detected low or moderate in all the three types of meat. The biogenic amines of the fresh meat sold in the wet market is generally higher than the reported values. The mechanisms of biogenic amines-dansyl-chloride formation were investigated and proposed. PRACTICAL APPLICATION: The biogenic amine derivatization method was improved. The improved derivatization method can be potentially used for various food products beside meats for routine biogenic amine analyses due to its fast analysis time and simplicity. High levels of biogenic amines were generally found in the meat sold in the wet markets. However, proper handling of the raw meat can reduce the risk of infection.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
  6. Quality by Design-based RP-HPLC Method for Estimation of Curcumin in Rat Plasma and Fecal Microbiota Extract-based Solid Self-nano Emulsifying Drug Delivery System
    Corrie L, Gulati M, Kaur J, Awasthi A, Vishwas S, Ramanunny AK, et al.
    Curr Drug Res Rev, 2023;15(3):272-285.
    PMID: 36683365 DOI: 10.2174/2589977515666230120140543
    BACKGROUND: Curcumin (CRM) is known to possess various therapeutic properties, such as anti-inflammatory and antidiabetic properties, and is, therefore, considered to be an effective therapeutic.

    OBJECTIVE: A sensitive method for the estimation of CRM in plasma, as well as fecal matter-based solid self-nano emulsifying drug delivery system (S-SNEDDS), has been reported for the first time.

    METHODS: A bioanalytical method was optimized using Box-Behnken Design having 13 runs and 3 responses. The optimized method was developed using methanol and water (70:30 v/v) with a flow rate of 1 mL/min. Quercetin was used as an internal standard. A specificity test was also performed for the developed CRM solid self-nano emulsifying drug delivery system.

    RESULTS: The retention time of CRM was found to be 14.18 minutes. The developed method was validated and found to be linear in the range of 50-250 ng/mL with an R2 of 0.999. Accuracy studies indicated that CRM had a percentage recovery of less than 105% and more than 95%, respectively. Precision studies were carried out for inter, intraday, and inter-analyst precision, and the %RSD was found to be less than 2%. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 3.37 ng/mL and 10.23 ng/mL, respectively. Stability studies for shortterm, long term and freeze-thaw cycles showed a %RSD of less than 2%, indicating the stability of CRM in the plasma matrix. Moreover, the blank fecal microbiota extract slurry did not show any peak at the retention time of CRM in a CRM-loaded solid nanoemulsifying drug delivery system containing fecal microbiota extract indicating its specificity.

    CONCLUSION: Hence, the developed method can have clinical implications as it helps estimate CRM in blood samples and also provides a simple and sensitive method for the estimation of plant-based flavonoids along with fecal microbiota extract formulations.

    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
  7. Fulltext Simultaneous determination of tramadol and paracetamol in human plasma using LC-MS/MS and application in bioequivalence study of -fixed-dose combination
    Loh GOK, Wong EYL, Goh CZ, Tan YTF, Lee YL, Pang LH, et al.
    Ann Med, 2023;55(2):2270502.
    PMID: 37857359 DOI: 10.1080/07853890.2023.2270502
    The study aimed to develop a sensitive and high-throughput liquid chromatography coupled with tandem mass spectrometry method to quantify concentrations of tramadol and paracetamol simultaneously in human plasma. Sample preparation involved single-step protein precipitation using methanol and two deuterated internal standards, tramadol D6 and paracetamol D4. Agilent Poroshell 120 EC-C18 (100 × 2.1 mm, 2.1 µm) analytical column was employed to achieve chromatographic separation. Detection was in positive ion multiple reaction monitoring mode. A tailing factor (Tf) of <1.2, separation factor (K prime) of >1.5 from the column dead time and signal-to-noise (S/N) ratio >10, were obtained for analytes and internal standards. The standard curve was linear over the concentration range of 2.5-500.00 ng/mL for tramadol and 0.025-20.00 μg/mL for paracetamol. A small injection volume of 1 µL, low flow rate of 440 µL/min and short analysis time of 3.5 min reduced the solvent consumption, analysis cost and system contamination. The results of method validation parameters fulfilled the acceptance criteria of bioanalytical guidelines. The method was successfully applied to a bioequivalence study of fixed-dose combination products of tramadol and paracetamol in Malaysian healthy subjects.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
  8. Fulltext Fast and Sensitive HPLC-ESI-MS/MS Method for Etoricoxib Quantification in Human Plasma and Application to Bioequivalence Study
    Loh GOK, Wong EYL, Tan YTF, Heng SC, Saaid M, Cheah KY, et al.
    Molecules, 2022 Sep 04;27(17).
    PMID: 36080473 DOI: 10.3390/molecules27175706
    Etoricoxib is a non-steroidal anti-inflammatory drug (NSAID) used to treat pain and inflammation. The objective of the current study was to develop a sensitive, fast and high-throughput HPLC-ESI-MS/MS method to measure etoricoxib levels in human plasma using a one-step methanol protein precipitation technique. A tandem mass spectrometer equipped with an electrospray ionization (ESI) source operated in a positive mode and multiple reaction monitoring (MRM) were used for data collection. The quantitative MRM transition ions were m/z 359.15 > 279.10 and m/z 363.10 > 282.10 for etoricoxib and IS. The linear range was from 10.00 to 4000.39 ng/mL and the validation parameters were within the acceptance limits of the European Medicine Agency (EMA) and Food and Drug Analysis (FDA) guidelines. The present method was sensitive (10.00 ng/mL with S/N > 40), simple, selective (K prime > 2), and fast (short run time of 2 min), with negligible matrix effect and consistent recovery, suitable for high throughput analysis. The method was used to quantitate etoricoxib plasma concentrations in a bioequivalence study of two 120 mg etoricoxib formulations. Incurred sample reanalysis results further supported that the method was robust and reproducible.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
  9. Development and validation of a gradient HPLC-UV method for mitragynine following in vitro skin permeation studies
    Sim YS, Chong ZY, Azizi J, Goh CF
    J Chromatogr B Analyt Technol Biomed Life Sci, 2022 Jul 15;1204:123316.
    PMID: 35700649 DOI: 10.1016/j.jchromb.2022.123316
    Mitragynine is a promising candidate for pain relief and opiate replacement but the investigations for drug delivery are lacking. This study aims to investigate the potential of mitragynine to be delivered through the skin with an emphasis on developing and validating a gradient HPLC-UV analytical method to determine mitragynine in the samples collected during in vitro skin permeation studies. The optimised method involves a gradient elution using a C18 column with a mobile phase comprising acetonitrile and 0.1 %v/v of formic acid (0-1 min: 30:70 to 70:30 (v/v) and hold up to 4 min; 4-6 min: return to 30:70 (v/v) and hold up to 10 min) at a flow rate of 1.2 mL/min. This method was validated based on the standards set by the International Council on Harmonisation guidelines. The method showed mitragynine elution at ∼ 4 min with adequate linearity (R2 ≥ 0.999 for concentration ranges of 0.5-10 and 10-175 μg/mL) and acceptable limits of detection and quantification at 0.47 and 1.43 μg/mL, respectively. The analytical performance is robust with excellent precision and accuracy. This method was used to evaluate the in vitro skin permeation of mitragynine (5 %w/v) from simple solvent systems over 48 hr. The results showed a cumulative amount of mitragynine permeated at ∼ 11 μg/cm2 for dimethyl sulfoxide and ∼ 4 μg/cm2 for propylene glycol. The study not only addressed the issues of the currently available HPLC-UV methods that limit the direct application but also affirmed the potential of mitragynine to be delivered through the skin.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
  10. Magnetic molecularly imprinted polymer nanoparticles for the extraction and clean-up of thiamethoxam and thiacloprid in light and dark honey
    Abdulhussein AQ, Jamil AKM, Bakar NKA
    Food Chem, 2021 Oct 15;359:129936.
    PMID: 33957328 DOI: 10.1016/j.foodchem.2021.129936
    In this work, new selective and sensitive dual-template molecularly imprinted polymer nanoparticles (MIPs) were synthesized and characterized. Sorbent MIPs were investigated for simultaneous extraction and clean-up of thiamethoxam and thiacloprid from light and dark honey samples. In this study, ultra-high-performance liquid chromatography-tandem mass spectrometry triple-quadrupole (UHPLC-MS/MS) (QQQ) was used to detect and quantify the pesticides. The kinetic model with adsorption kinetics of sorbent was investigated. The optimal adsorption conditions were 80 mg of polymer MIPs, a 30-min extraction time, and a pH of 7. The detection limit (LOD) and the quantification limit (LOQ) varied from 0.045 to 0.070 µg kg-1 and from 0.07 to 0.10 µg kg-1, respectively. The intra-day and inter-day precision (RSD, %) ranged from 1.3 to 2.0% and from 8.2 to 12.0%, respectively. The recovery of thiamethoxam and thiacloprid ranged from 96.8 to 106.5% and 95.3 to 104.4%, respectively, in light and dark honey samples.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
  11. Evaluation of role of HPLC (Merits & Pitfalls), in the diagnosis of various hemoglobinopathies & thalassemic syndromes
    Baig MA, Swamy KB, Baksh AD, Bahashwan A, Moshrif Y, Al Sawat A, et al.
    Indian J Pathol Microbiol, 2021 8 4;64(3):518-523.
    PMID: 34341263 DOI: 10.4103/IJPM.IJPM_709_20
    Background: : HPLC is one of the most important tools for accurate diagnosis of hemoglobinopathies and thalassemias. The advantage of the HPLC system is the excellent resolution, reproducibility &quantification of several normal and abnormal hemoglobin.

    Results: BIO RAD Variant II analyzer was used. Sickle cell syndromes including double heterozygous states accounted for 56.13% of total cases. HbSS, HbS/β0-th, HbS/β+-th β-thal trait comprises 29%, 6.5%, 5.1%& 10% of total cases respectively with mean MCV (fl) = 84, 68,71,64 respectively. The Mean HbA2 for β-thal trait, HbE trait &HbE-β thal showed 5.1 ± 1.1, 19 ± 9 & 24 ± 8 respectively. HbF is increased in 8.6% case (excluding SC syndromes & β-thal disorders), of these 5.5% were infants & 12 cases of Aplastic Anemias. Peak P2 >7% (2.4% cases) was seen in uncontrolled diabetes mellitus which on quantification showed HbA1C = 8 ± 2.1 mmol/L.

    Discussion: : HPLC in correlation with CBC parameters & family studies can aid in the diagnosis of majority of Hemoglobinopathies and thalassemic syndrome. The CBC & HPLC parameters of the present study are in good correlation with the research conducted by Tejinder Sing, RiouJ & Alla Joutovsky. Present study showed HPLC comprehensively characterizing HbS, A, A2, F, S, C, D from each other & was also applicable for the quantification of HbA1c for the monitoring of Diabetes Mellitus.

    Conclusion: : The merits of HPLC are small quantity of sample required, economical, less TAT, accurate categorization of HbS, HbA2 & F. But one has to be aware of the limitations and problems associated with this method due to variant hemoglobin within the same retention windows. The present findings show HPLC as an excellent & powerful diagnostic tool for the direct identification of hemoglobin variants with a high degree of precision in the quantification of normal and abnormal hemoglobin fractions.

    Matched MeSH terms: Chromatography, High Pressure Liquid/methods*
  12. Solid-phase extraction of non-steroidal anti-inflammatory drugs in human plasma and water samples using sol-gel-based metal-organic framework coating
    Amiri A, Ghaemi F
    J Chromatogr A, 2021 Jul 05;1648:462168.
    PMID: 33984648 DOI: 10.1016/j.chroma.2021.462168
    In this research, the Cu-based metal-organic framework (MOF-199) was fabricated and coated on the stainless steel mesh as substrates through sol-gel procedure. Then the coated substrates were placed in a small column known as solid-phase extraction cartridge. The SPE based coated stainless steel mesh coupled with high-performance liquid chromatography-UV detector (HPLC-UV) was used for the fast extraction, and quantification of non-steroidal anti-inflammatory drugs (NSAIDs) from human plasma and water samples. To find optimum extraction conditions, the impacts of effective parameters on analytical performance like sample pH, sample volume, type, and volume of desorption solvent were optimized. At the optimized conditions, calibration graphs of analytes were linear in the concentration range of 0.03-300 ng mL-1 for water samples, and 0.1-200 ng mL-1 for plasma samples. The correlation coefficients were in the range of 0.9938 to 0.9989. Also, the limits of detection (LODs) were from 0.01 to 0.02 ng mL-1 for water samples and 0.03 to 0.1 ng mL-1 for plasma samples. The cartridge repeatability was studied at different values, and the relative standard deviations (RSDs%) were achieved between 3.5 and 5.1%. Consequently, this procedure was successfully used in the extraction and detection of NSAIDs in real water and plasma samples with relative recoveries ranged from 93.6 to 99.6%.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
  13. LC-PDA-MS/MS-Based Characterization of Key Phytochemicals in Eurycoma Longifolia Roots
    Chua LS, Segaran A, Wong HJ
    J Chromatogr Sci, 2021 Jun 21;59(7):659-669.
    PMID: 33876232 DOI: 10.1093/chromsci/bmab041
    The objective of the study was to fractionate the crude extract of Eurycoma longifolia (E. longifolia) roots and identify the intense peaks using HPLC-PDA-MS/MS, UPLC-MS/MS and H-NMR. Column chromatography was used to fractionate the crude extract into individual fractions using six solvent systems ranged from ethyl acetate, methanol and water in increasing polarity. Two fractions with nearly pure and intense peaks were selected for compound identification. Chromenone (coumarin) and chromone derivatives were putatively identified, besides several previously reported quassinoid glycosides (eurycomanone derived glycoside, 2,3-dehydro-4α-hydroxylongilactone glucoside, eurycomanol glycoside and eurycomanol trimer) in the fraction 11 of 100% methanol. A newly reported compound, namely hydroxyl glyyunanprosapogenin D (838 g/mol) was proposed to be the compound detected in the fraction 11 of 50% ethyl acetate and 50% methanol. This is also the first study to report the identification of chromenones and chromones in E. longifolia extract.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods*
  14. Fulltext UHPLC-UV/PDA Method Validation for Simultaneous Quantification of Luteolin and Apigenin Derivatives from Elaeis guineensis Leaf Extracts: An Application for Antioxidant Herbal Preparation
    Che Zain MS, Osman MF, Lee SY, Shaari K
    Molecules, 2021 Feb 19;26(4).
    PMID: 33669484 DOI: 10.3390/molecules26041084
    Luteolin and apigenin derivatives present in oil palm (Elaeis guineensis) leaves (OPL) are reported to possess excellent antioxidant properties relating to numerous health benefits. To meet the global demand for flavonoids, OPL, which is plentifully generated as an agricultural by-product from oil palm plantations, can be further exploited as a new source of natural antioxidant compounds. However, to produce a standardized herbal preparation, validation of the quantification method for these compounds is required. Therefore, in this investigation, we developed and validated an improved and rapid analytical method, ultra-high-performance liquid chromatography equipped with ultraviolet/photodiode array (UHPLC-UV/PDA) for the quantification of 12 luteolin and apigenin derivatives, particularly focusing on flavonoid isomeric pairs: orientin/isoorientin and vitexin/isovitexin, present in various OPL extracts. Several validation parameters were assessed, resulting in the UHPLC-UV/PDA technique offering good specificity, linearity, accuracy, precision, and robustness, where the values were within acceptable limits. Subsequently, the validated method was employed to quantify luteolin and apigenin derivatives from OPL subjected to different drying treatments and extraction with various solvent systems, giving total luteolin (TLC) and apigenin content (TAC) in the range of 2.04-56.30 and 1.84-160.38 µg/mg extract, respectively. Additionally, partial least square (PLS) analysis disclosed the combination of freeze dry-aqueous methanol yielded OPL extracts with high TLC and TAC, which are strongly correlated with antioxidant activity. Therefore, we provide the first validation report of the UHPLC-UV/PDA method for quantification of luteolin and apigenin derivatives present in various OPL extracts, suggesting that this approach could be employed in standardized herbal preparations by adopting orientin, isoorientin, vitexin, and isovitexin as chemical markers.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods*
  15. Fulltext Mechanistic Studies of the Antiallergic Activity of Phyllanthus amarus Schum. & Thonn. and Its Compounds
    Abd Rani NZ, Lam KW, Jalil J, Mohamad HF, Mat Ali MS, Husain K
    Molecules, 2021 Jan 28;26(3).
    PMID: 33525733 DOI: 10.3390/molecules26030695
    Phyllanthus amarus Schum. & Thonn. (Phyllanthaceae) is a medicinal plant that is commonly used to treat diseases such as asthma, diabetes, and anemia. This study aimed to examine the antiallergic activity of P. amarus extract and its compounds. The antiallergic activity was determined by measuring the concentration of allergy markers release from rat basophilic leukemia (RBL-2H3) cells with ketotifen fumarate as the positive control. As a result, P. amarus did not stabilize mast cell degranulation but exhibited antihistamine activity. The antihistamine activity was evaluated by conducting a competition radioligand binding assay on the histamine 1 receptor (H1R). Four compounds were identified from the high performance liquid chromatography (HPLC) analysis which were phyllanthin (1), hypophyllanthin (2), niranthin (3), and corilagin (4). To gain insights into the binding interactions of the most active compound hypophyllanthin (2), molecular docking was conducted and found that hypophyllanthin (2) exhibited favorable binding in the H1R binding site. In conclusion, P. amarus and hypophyllanthin (2) could potentially exhibit antiallergic activity by preventing the activation of the H1 receptor.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
  16. Simple and fast LC-MS/MS method for quantification of terazosin in human plasma and application to bioequivalence study
    Loh GOK, Wong EYL, Tan YTF, Ong LM, Ng RS, Wee HC, et al.
    J Chromatogr B Analyt Technol Biomed Life Sci, 2021 Jan 15;1163:122517.
    PMID: 33429127 DOI: 10.1016/j.jchromb.2020.122517
    A simple, fast and sensitive LC-MS/MS method was developed to quantify terazosin in human plasma. The mobile phase consisted of acetonitrile-0.1% (v/v) formic acid (70:30, v/v). Prazosin was used as internal standard (IS). As deproteinization agent, acetonitrile produced a clean sample. A higher response intensity with more symmetrical peak was obtained using Agilent Poroshell 120 EC-C18 - Fast LC column (100 × 2.1mmID, 2.7 μm) compared with Kinetex XB-C18 (100 × 2.1 mm, 2.6 µm) column. The response of terazosin and IS were approximately two times in citrate phosphate dextrose (CPD) plasma compared with dipotassium ethylenediaminetetraacetic acid (K2EDTA) plasma. Plasma calibration curve was linear from 1.0 to 100.0 ng/mL, with coefficient of determination r2 ≥ 0.99. The within-run and between-run precision values (CV, %) were <5.2% and <7.8%, while accuracy values were 102.8-112.7% and 103.4-112.2%. The extended run accuracy was 98.6-102.8% and precision (CV, %) 4.3-10.4%. The recovery of analyte was >98% and IS >94%. Terazosin in plasma kept at benchtop was stable for 24 h, in autosampler tray for 48 h, in instrumentation room for 48 h, for 7 freeze-thaw cycles and in freezer for 140 days. Terazosin and IS stock standard solutions were stable for 140 days at room temperature and in the chiller. The high throughput method was successfully utilized to measure 935 samples in a bioequivalence study of terazosin.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods*
  17. Latanoprost Quantification in Ocular Implants and Tissues: HPLC-Fluorescence vs HPLC-UV
    Soliman K, Jirjees F, Sonawane R, Sheshala R, Wang Y, Jones D, et al.
    J Chromatogr Sci, 2021 Jan 01;59(1):64-70.
    PMID: 33047781 DOI: 10.1093/chromsci/bmaa078
    Anti-glaucoma latanoprost-loaded ocular implants provide prolonged delivery and enhanced bioavailability relative to the conventional eye drops. This study aims at the development and validation of a reversed-phase high-performance liquid chromatography method for quantitative analysis of nanogram levels of latanoprost in the eye, and for the first time, compares the use of fluorescence vs ultraviolet (UV) detectors in latanoprost quantification. The mobile phase was composed of acetonitrile:0.1% v/v formic acid (60:40, v/v) with a flow rate of 1 mL/min and separation was done using a C18 column at temperature 40°C. The fluorescence excitation and emission wavelengths were set at 265 and 285 nm, respectively, while the UV absorption was measured at 200 nm. The latanoprost concentration-peak area relationship maintained its linearity (R2 = 0.9999) over concentration ranges of 0.063-10 μg/mL and 0.212-10 μg/mL for the fluorescence and UV detectors, respectively. The UV detector showed better precision, while the fluorescence detector exhibited higher robustness and greater sensitivity, with a detection limit of 0.021 μg/mL. The fluorescence detector was selected for quantification of latanoprost released from ocular implants in vitro and in porcine ocular tissues. The developed method is a robust, rapid and cost-effective alternative to liquid chromatography-mass spectrometry for routine analysis of latanoprost released from ocular implants.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods*
  18. Simple and rapid LC-MS/MS method for determination of sitagliptin in human plasma and application to bioequivalence study
    Loh GOK, Wong EYL, Tan YTF, Lee YL, Pang LH, Chin MC, et al.
    J Chromatogr B Analyt Technol Biomed Life Sci, 2020 Nov 30;1159:122337.
    PMID: 32905988 DOI: 10.1016/j.jchromb.2020.122337
    A simple, rapid, sensitive, and reproducible liquid chromatography-tandem mass spectrometry method was developed to determine sitagliptin in human plasma. Diphenhydramine HCl was used as internal standard (IS). The chromatographic separation was achieved using Agilent Poroshell 120 EC-C18 - Fast LC column (100 × 2.1mmID, 2.7) fitted with UHPLC Guard Poroshell 120 EC-C18 (5 × 2.1mmID, 2.7 µm). The mobile phase consisted of 0.1% v/v formic acid and methanol (45:55, v/v) run at a flow rate of 0.45 mL/min at 30 °C. Methanol produced relatively cleaner plasma sample as deproteinization agent. Polytetrafluoroethylene membrane was preferred over nylon membrane as the former produced clear plasma samples. The standard calibration curve was linear over the concentration range of 5-500.03 ng/mL. The within-run precision was 0.53-7.12% and accuracy 87.09-105.05%. The between-run precision was 4.74-11.68% and accuracy 95.02-97.36%. The extended run precision was 3.60-6.88% and accuracy 93.18-95.82%. The recovery of analyte and IS was consistent. Sitagliptin in plasma was stable at benchtop (short term) for 24 h, in autosampler tray for 48 h, in instrumentation room for 48 h (post-preparative), after 7 freeze-thaw cycles (-20 ± 10 °C), and 62 days in the freezer (-20 ± 10 °C). Both sitagliptin (analyte) and IS stock solutions were stable for 62 days when kept at room temperature (25 ± 4 °C) and in chiller (2-8 °C). The validated method was successfully applied to a bioequivalence study of two sitagliptin formulations involving 26 healthy Malaysian volunteers.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods*
  19. Occurrence and potential risk of organophosphorus pesticides in urbanised Linggi River, Negeri Sembilan, Malaysia
    Zainuddin AH, Wee SY, Aris AZ
    Environ Geochem Health, 2020 Nov;42(11):3703-3715.
    PMID: 32488800 DOI: 10.1007/s10653-020-00604-4
    The application of organophosphorus pesticides (OPPs) increased gradually because of the rise in global food demand that triggered the agriculture sector to increase the production, leading to OPP residues in the surface water. This study elucidated the presence of OPPs and estimated its ecological risk in the riverine ecosystem of the urbanised Linggi River, Negeri Sembilan, Malaysia. The OPP concentration in surface water was determined using solid-phase extraction method and high-performance liquid chromatography coupled with diode array detection. Further, the ecological risk was estimated by using the risk quotient (RQ) method. The three OPPs, i.e. chlorpyrifos, diazinon, and quinalphos were detected with mean concentrations of 0.0275 µg/L, 0.0328 µg/L, and 0.0362 µg/L, respectively. The OPPs were at high risk (in general and worst cases) under acute exposure. The estimated risk of diazinon was observed as medium for general (RQm = 0.5857) and high for worst cases (RQex = 4.4678). Notably, the estimated risk for chlorpyrifos was high for both general and worst cases (RQm = 1.9643 and RQex = 11.5643) towards the aquatic ecosystem of the Linggi River. Chronic risk of quinalphos remains unknown because of the absence of toxicity endpoints. This study presented clear knowledge regarding OPP contamination and possible risk for aquatic ecosystems. Hence, OPPs should be listed as one of the main priority contaminants in pesticide mitigation management in the future.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods
  20. Fulltext Development of HPLC Method for Quantification of Sinigrin from Raphanus sativus Roots and Evaluation of Its Anticancer Potential
    Nair AB, Gandhi D, Patel SS, Morsy MA, Gorain B, Attimarad M, et al.
    Molecules, 2020 Oct 26;25(21).
    PMID: 33114598 DOI: 10.3390/molecules25214947
    Sinigrin, a precursor of allyl isothiocyanate, present in the Raphanus sativus exhibits diverse biological activities, and has an immense role against cancer proliferation. Therefore, the objective of this study was to quantify the sinigrin in the R. sativus roots using developed and validated RP-HPLC method and further evaluated its' anticancer activity. To achieve the objective, the roots of R. sativus were lyophilized to obtain a stable powder, which were extracted and passed through an ion-exchange column to obtain sinigrin-rich fraction. The RP-HPLC method using C18 analytical column was used for chromatographic separation and quantification of sinigrin in the prepared fraction, which was attained using the mobile phase consisting of 20 mM tetrabutylammonium: acetonitrile (80:20%, v/v at pH 7.0) at a flow rate of 0.5 mL/min. The chromatographic peak for sinigrin was showed at 3.592 min for pure sinigrin, where a good linearity was achieved within the concentration range of 50 to 800 µg/mL (R2 > 0.99), with an excellent accuracy (-1.37% and -1.29%) and precision (1.43% and 0.94%), for intra and inter-day, respectively. Finally, the MTT assay was performed for the sinigrin-rich fraction using three different human cancer cell lines, viz. prostate cancer (DU-145), colon adenocarcinoma (HCT-15), and melanoma (A-375). The cell-based assays were extended to conduct apoptotic and caspase-3 activities, to determine the mechanism of action of sinigrin in the treatment of cancer. MTT assay showed IC50 values of 15.88, 21.42, and 24.58 µg/mL for DU-145, HCT-15, and A-375 cell lines, respectively. Increased cellular apoptosis and caspase-3 expression were observed with sinigrin-rich fraction, indicating significant increase in overexpression of caspase-3 in DU-145 cells. In conclusion, a simple, sensitive, fast, and accurate RP-HPLC method was developed for the estimation of sinigrin in the prepared fraction. The data observed here indicate that sinigrin can be beneficial in treating prostate cancer possibly by inducing apoptosis.
    Matched MeSH terms: Chromatography, High Pressure Liquid/methods*
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