11,271 results match your criteria rp-hplc methods

Chromatomembrane pre-concentration of phenols using a new 3D printed micro flow cell followed by RP HPLC determination.

J Sep Sci 2021 Apr 13. Epub 2021 Apr 13.

Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow, Moscow, 119991, Russian Federation.

Chromatomembrane process represents a universal approach to the separation of compounds in liquid-gas and liquid-liquid phases systems. However, the broad application of chromatomembrane separation methods in chemical analysis is restricted by the absence of serially produced chromatomembrane flow cells and the difficulties of their laboratory production. The present work addresses the preparation of chromatomembrane flow cell by using 3D printing. Read More

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Bioanalytical method development for momordicinin and its application to long term pharmacokinetics in diabetic rats.

Drug Dev Ind Pharm 2021 Apr 5:1-25. Epub 2021 Apr 5.

Department of Pharmaceutical chemistry, Poona College of Pharmacy, Bharati Vidyapeeth Deemed to be University, Pune, Maharashtra, India.

Objective: To develop and validate bioanalytical RP-HPLC method to evaluate pharmacokinetics and tissue distribution pattern of momordicinin (MRN).

Significance: MRN is one of the major cucurbitane triterpenoid found in linn (MC). However MRN has not been explored for its pharmacokinetic profile, tissue distribution and stability in order to establish it as an antidiabetic agent. Read More

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Selection of Gut-Resistant Bacteria and Construction of Microbial Consortia for Improving Gluten Digestion under Simulated Gastrointestinal Conditions.

Nutrients 2021 Mar 19;13(3). Epub 2021 Mar 19.

Faculty of Science and Technology, Free University of Bozen, 39100 Bolzano, Italy.

This work aimed to define the microbial consortia that are able to digest gluten into non-toxic and non-immunogenic peptides in the human gastrointestinal tract.

Methods: 131 out of 504 tested and lactic acid bacteria, specifically (64), lactobacilli (63), (1), and (3), showed strong gastrointestinal resistance and were selected for their PepN, PepI, PepX, PepO, and PepP activities toward synthetic substrates. Based on multivariate analysis, 24 strains were clearly distinct from the other tested strains based on having the highest enzymatic activities. Read More

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Antioxidant Properties of Pecan Shell Bioactive Components of Different Cultivars and Extraction Methods.

Foods 2021 Mar 27;10(4). Epub 2021 Mar 27.

School of Nutrition and Food Sciences, Louisiana State University AgCenter, 261 Knapp Hall, Baton Rouge, LA 70803, USA.

Pecan shells are a rich source of various bioactive compounds with potential antioxidant and antimicrobial properties. This study investigated the effect of pecan variety and method extraction on the antioxidant property of shell extracts. Twenty different varieties of pecan shells were subjected to either aqueous or ethanolic extraction and were examined for total phenolics and antiradical activity. Read More

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Chromatographic Analysis for Targeted Metabolomics of Antioxidant and Flavor-Related Metabolites in Tomato.

Bio Protoc 2021 Mar 5;11(5):e3929. Epub 2021 Mar 5.

Department of Molecular Biology and Genetics, Faculty of Science, Izmir Institute of Technology, Izmir, Turkey.

Targeted metabolomics is a useful approach to evaluate crop breeding studies. Antioxidant and flavor-related traits are of increasing interest and are considered quality traits in tomato breeding. The present study presents chromatographic methods to study antioxidants (carotenoids, vitamin C, vitamin E, phenolic compounds, and glutathione) and flavor-related characters (sugars and organic acids) in tomato. Read More

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Determination of adenine nucleotides by the modified method of high-performance liquid chromatography.

Klin Lab Diagn 2021 Mar;66(3):172-176

Institute of Physiology of Komi Science Centre of the Ural Branch of the Russian Academy of Sciences, FCR Komi SC UB RAS.

Adenine nucleotides (ATP, ADP and AMP) play a central role in the regulation of metabolism and energy: they provide the energy balance of the cell, determine its redox state, act as allosteric effectors of a number of enzymes, modulate signaling and transcription factors and activate oxidation or biosynthesis substrates. A large number of methods have been developed to determine the level of ATP, ADP and AMP, but the most universal and effective method for the separation and analysis of complex mixtures is the reversed-phase high-performance liquid chromatography method (RP-HPLC). The aim of this study is to determine the optimal conditions for the qualitative separation and quantitative determination of standard solutions of ATP (1 mmol/l), ADP (0,5 mmol/l) and AMP (0,1 mmol/l) by RP-HPLC. Read More

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Green micellar solvent-free HPLC and spectrofluorimetric determination of favipiravir as one of COVID-19 antiviral regimens.

Microchem J 2021 Jun 23;165:106189. Epub 2021 Mar 23.

Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Port-Said University, Egypt.

Quality control (QC) of pharmaceutical products requires fast, sensitive as well as economic methodologies in order to provide high through output at low cost which are the main aspects considered by such economic facilities. Meanwhile, the ecological impacts must be considered by researchers to minimize the hazardous effects of research laboratories. Favipiravir (FAV) is an antiviral agent recently approved for treatment of COVID-19 infections during 2020 pandemic crisis, so the size of its production by international pharmaceutical corporations evolved dramatically within the past few months. Read More

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Isolation of HLA Bound Peptides by Immunoaffinity Capture and Identification by Mass Spectrometry.

Curr Protoc 2021 Mar;1(3):e92

Department of Biochemistry and Molecular Biology and Infection and Immunity Program, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia.

This article describes the purification of HLA-bound peptides and their subsequent sequencing by mass spectrometry. These methods can be used for both HLA class I and class II molecules and can be adapted to different species depending on the availability of specific antibodies. Peptides can be successfully isolated from a variety of sample types, including in vitro cultured cells and primary tissues. Read More

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Development and validation of a simple, selective, and sensitive LC-MS/MS assay for the quantification of remdesivir in human plasma.

J Chromatogr B Analyt Technol Biomed Life Sci 2021 Mar 10;1171:122641. Epub 2021 Mar 10.

Clinical Pharmacology Program, Office of the Clinical Director, National Cancer Institute, Bethesda, MD, United States. Electronic address:

Remdesivir, formerly GS-5734, has recently become the first antiviral drug approved by the U.S. Food and Drug Administration (FDA) to treat COVID-19, the disease caused by SARS-CoV-2. Read More

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A validated HPLC-UV method for the analysis of phenolic compounds in Brazilian red propolis and Dalbergia ecastaphyllum.

J Pharm Biomed Anal 2021 May 16;198:114029. Epub 2021 Mar 16.

School of Pharmaceutical Sciences of Ribeirão Preto, Ribeirão Preto, University of São Paulo, Brazil. Electronic address:

Propolis is a natural product produced from the interaction between bees and plants. Brazilian red propolis results from Apis mellifera collection of resins from two plant species, being Dalbergia ecastaphyllum(L.) Taub, Fabaceae, the primary botanical source, containing isoflavonoids and other characteristic phenolic compounds. Read More

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Insulinotropic and antidiabetic properties of Eucalyptus citriodora leaves and isolation of bioactive phytomolecules.

J Pharm Pharmacol 2021 Mar 23. Epub 2021 Mar 23.

School of Biomedical Sciences, Ulster University, Coleraine, Northern Ireland, UK.

Objective: The aim of this study was to delineate the mechanisms of action of the plant Eucalyptus citriodora used traditionally for the treatment of type 2 diabetes.

Methods: Insulin secretion and signal transduction were measured using clonal pancreatic β-cells and mouse islets. Glucose uptake was assessed using 3T3-L1 adipocytes and in vitro systems assessed additional glucose-lowering actions. Read More

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Validation of plasma amino acid profile using UHPLC-mass spectrometer (QDa) as a screening method in a metabolic disorders reference centre: Performance and accreditation concerns.

Clin Biochem 2021 Mar 15. Epub 2021 Mar 15.

Laboratoire de Biochimie et Biologie Moléculaire, CHRU de Tours, Tours, France; Unité INSERM U1253, équipe "neurogénomique et physiopathologie neuronale", Université de Tours, Tours, France; Centre de référence des maladies héréditaires de métabolisme - filière G2M, France.

Introduction: Amino acid (AA) analysis in plasma is essential for diagnosis and monitoring of inborn errors of metabolism (IEM). The efficacy of patient management is governed by the rapidity of AA profile availability, along with the robustness of the method. French quality guidelines and progress made in analytical techniques have led biologists to develop AA profile exploration via mass spectrometry (MS). Read More

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Reverse Phase-high-performance Liquid Chromatography (RP-HPLC) Analysis of Globin Chains from Human Erythroid Cells.

Bio Protoc 2021 Jan 20;11(2):e3899. Epub 2021 Jan 20.

Université de Paris, Imagine Institute, Laboratory of chromatin and gene regulation during development, INSERM UMR 1163, F-75015, Paris, France.

β-hemoglobinopathies are severe genetic disorders characterized either by the abnormal synthesis of the adult β-globin chains of the hemoglobin (Hb) tetramer (β-globin chains) in sickle cell disease (SCD) or by the reduced β-globin production in β-thalassemia. The identification and quantification of globin chains are crucial for the diagnosis of these diseases and for testing new therapeutic approaches aimed at correcting the β-hemoglobinopathy phenotype. Conventional techniques to detect the different Hb molecules include cellulose-acetate electrophoresis (CEA), capillary electrophoresis (CE), isoelectric focusing (IEF), and cation-exchange-HPLC (CE-HPLC). Read More

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January 2021

Novel bioactive peptides of Achillea eriophora show anticancer and antioxidant activities.

Bioorg Chem 2021 Feb 24;110:104777. Epub 2021 Feb 24.

Center of Plant Virology Research, Shiraz University, Shiraz, Iran.

Despite the limitations of current methods in cancer treatment, the use of bioactive peptides can be as an alternative to treat today. Therefore, isolation and relative purification of bioactive peptides was carried out form Achillea eriophora using a Sep-Pak C18 SPE cartridge and Amicon® Ultra Centrifugal Filters. The presence of desired peptides was checked using RP-HPLC and confirmed using LC-MS. Read More

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February 2021

Determination of individual oligonucleotide impurities by small amine ion pair-RP HPLC MS and MS/MS: n - 1 impurities.

J Chromatogr B Analyt Technol Biomed Life Sci 2021 Apr 1;1169:122611. Epub 2021 Mar 1.

Ionis Pharmaceuticals, Carlsbad, CA 92010, United States.

Ion pair-reversed phase (IP-RP) HPLC is one of the most widely used methods for the analysis of oligonucleotide impurities. The method is compatible with mass spectrometry and has been used to guide the development of improved synthesis and purification approaches. The ability to detect and characterize impurities depends on the reagents and the IP buffer system employed, as each can directly affect the degree of chromatographic separation and the sensitivity of detection by MS. Read More

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Strategy for stereospecific characterization of natural triacylglycerols using multidimensional chromatography and mass spectrometry.

J Chromatogr A 2021 Mar 12;1641:461992. Epub 2021 Feb 12.

Food Chemistry and Food Development, Department of Life Technologies, University of Turku, FI-20014 Turku, Finland.

Stereoisomeric determination of individual triacylglycerols (TAGs) in natural oils and fats is a challenge due to similar physicochemical properties of TAGs with different fatty acid combinations. In this study, we present a strategy to resolve the enantiomeric composition of nutritionally important TAGs in sea buckthorn (Hippophaë rhamnoides) as an example food matrix. The targeted strategy combines 1) fatty acid profiling with GC, 2) separation of TAGs with RP-HPLC, 3) stereospecific separation with chiral-phase HPLC and 4) structural characterization with MS. Read More

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Development and validation of a stability indicating RP-HPLC-DAD method for the determination of bromazepam.

PLoS One 2021 10;16(3):e0244951. Epub 2021 Mar 10.

Faculty of Pharmacy, Pharmaceutical Analytical Chemistry Department, Beni-Suef University, Beni-Suef, Egypt.

A reliable, selective and sensitive stability-indicating RP-HPLC assay was established for the quantitation of bromazepam (BMZ) and one of the degradant and stated potential impurities; 2-(2-amino-5-bromobenzoyl) pyridine (ABP). The assay was accomplished on a C18 column (250 mm × 4.6 mm i. Read More

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Mass Spectrometry-Based Proteomics for Analysis of Hydrophilic Phosphopeptides.

Methods Mol Biol 2021 ;2259:247-257

Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, USA.

Protein phosphorylation is a critical posttranslational modification (PTM), with cell signaling networks being tightly regulated by protein phosphorylation. Despite recent technological advances in reversed-phase liquid chromatography (RPLC)-mass spectrometry (MS)-based proteomics, comprehensive phosphoproteomic coverage in complex biological systems remains challenging, especially for hydrophilic phosphopeptides that often have multiple phosphorylation sites. Herein, we describe an MS-based phosphoproteomics protocol for effective quantitative analysis of hydrophilic phosphopeptides. Read More

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Phytochemical and Antioxidant Activities of as Natural Functional Food from North Sulawesi Waters, Indonesia.

Pak J Biol Sci 2021 Jan;24(1):132-138

Background And Objective: Research to find functional food from new natural sources has caught the attention of many researchers through the characterization of phytochemicals and biological activities. One potential source of natural ingredients is the red alga Eucheuma spinosum, which has been used as a daily source of natural food. The purpose of this study was to obtain a prospective new source of natural antioxidants from various extracts of tropical red alga (E. Read More

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January 2021

Plasma Protein Binding Studies of Selected Group of Drugs Using TLC and HPLC Retention Data.

Pharmaceuticals (Basel) 2021 Feb 28;14(3). Epub 2021 Feb 28.

Department of Analytical Chemistry, Faculty of Pharmacy, Medical University of Lodz, 92-216 Lodz, Poland.

Plasma protein binding is an important determinant of the pharmacokinetic properties of chemical compounds in living organisms. The aim of the present study was to determine the index of protein binding affinity based on chromatographic experiments. The question is which chromatographic environment will best mimic the drug-protein binding conditions. Read More

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February 2021

Bioactive Phenolic Compounds from L.: Influence of the Extraction Conditions and Purification.

Molecules 2021 Feb 13;26(4). Epub 2021 Feb 13.

Department of Bioenergetics, Food Analysis and Microbiology, Institute of Food Technology and Nutrition, College of Natural Sciences, University of Rzeszów, 35-601 Rzeszów, Poland.

Our experiments may help to answer the question of whether cowslip ( L.) is a rich source of bioactive substances that can be obtained by efficient extraction with potential use as a food additive. A hypothesis assumed that the type of solvent used for plant extraction and the individual morphological parts of L. Read More

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February 2021

Analytical method development, validation and forced degradation studies for rutin, quercetin, curcumin, and piperine by RP-UFLC method.

Drug Dev Ind Pharm 2021 Apr 5:1-7. Epub 2021 Apr 5.

Department of Pharmaceutical Analysis, Sree Vidyanikethan College of Pharmacy, Tirupati, India.

Significance: Curcumin, rutin, and quercetin are well-known flavonoids and piperine is an alkaloid, commonly used as spices and traditionally used to treat a variety of conditions. In the current scenario, the stability problems of phytoconstituents are a major problem for regulators and because of the complex nature of the components of plant extracts.

Objective: A simple, fast, and sensitive ultra-force reverse phase liquid chromatography (RP-UFLC) has been developed, validated, and studied for degradation studies. Read More

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Identification of a novel proline-rich antimicrobial protein from the hemolymph of Antheraea mylitta.

Arch Insect Biochem Physiol 2021 Mar 28;106(3):e21771. Epub 2021 Feb 28.

Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, India.

Antimicrobial proteins (AMPs) are small, cationic proteins that exhibit activity against bacteria, viruses, parasites, fungi as well as boost host-specific innate immune responses. Insects produce these AMPs in the fat body and hemocytes, and release them into the hemolymph upon microbial infection. Hemolymph was collected from the bacterially immunized fifth instar larvae of tasar silkworm, Antheraea mylitta, and an AMP was purified by organic solvent extraction followed by size exclusion and reverse-phase high-pressure liquid chromatography. Read More

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Reduction of the extra-column band dispersion by a slow transport and splitting of a sample band in isocratic reversed-phase liquid chromatography.

J Chromatogr A 2021 Mar 13;1641:461996. Epub 2021 Feb 13.

Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan; GL Sciences Inc., 237-2 Sayamagahara, Iruma, Saitama 358-0032, Japan. Electronic address:

Sample introduction method was studied to reduce the extra-column effect in reversed-phase HPLC. Slow transport of a sample band (SToSB) in the pre-column space followed by the introduction of the band into the column at a near-optimum flow rate resulted in larger plate counts for a 1.0 mmID, 5 cm long column as much as 1. Read More

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Investigation into reversed-phase chromatography peptide separation systems Part IV: Characterisation of mobile phase selectivity differences.

J Chromatogr A 2021 Mar 9;1641:461986. Epub 2021 Feb 9.

Novo Nordisk A/S, Måløv, DK-2760, Denmark. Electronic address:

The differentiation of mobile phase compositions between sub-classes which exhibit distinct chromatographic selectivity (i.e. termed characterisation) towards a range of peptide probes with diverse functionality and hence the possibility for multi-modal retention mechanisms has been undertaken. Read More

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Optimization of pretreatment methods for cerebrospinal fluid metabolomics based on ultrahigh performance liquid chromatography/mass spectrometry.

J Pharm Biomed Anal 2021 Apr 29;197:113938. Epub 2021 Jan 29.

Department of Pharmaceutical Analysis, School of Pharmacy, Second Military Medical University, Shanghai, 200433, China; Shanghai Key Laboratory for Pharmaceutical Metabolite Research, Shanghai, 200433, China. Electronic address:

Sample pretreatment of cerebrospinal fluid (CSF) in metabolomics plays an important role in metabolic profiling study, especially for samples related to central nervous system diseases. However, there is few study about optimization of CSF metabolomics pretreatment. Therefore, it is an urgent need to optimize CSF pretreatment in order to promote the extraction efficiency of metabolites. Read More

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Beta-Alanine and Tris-(hydroxyl methyl) Aminomethane as Peak Modifiers in the Development of RP-HPLC Methods Using Aceclofenac and Haloperidol Hydrochloride as Exemplar Drugs.

J Chromatogr Sci 2021 Feb 23. Epub 2021 Feb 23.

Department of Pharmaceutical Analysis, JSS College of Pharmacy, Ooty (A Constituent College of JSS Academy of Higher Education & Research), Udhagamandalam, Tamilnadu-643001, India.

In the present analytical approach, beta-alanine (ALA) and tris-(hydroxyl methyl) aminomethane (TRIS) were investigated as peak modifiers due to their water solubility and their possible peak modifying a property. These reagents were tested for their efficacy on the elution of aceclofenac (ACF) and haloperidol hydrochloride (HLC) from C18 column (250 mm × 4.6 mm, 5 μ) equipped with a photodiode array detector. Read More

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February 2021

Standardization of chromatographic signals - Part II: Expanding instrument-agnostic fingerprints to reverse phase liquid chromatography.

J Chromatogr A 2021 Mar 8;1641:461973. Epub 2021 Feb 8.

Department of Analytical Chemistry, Faculty of Science, University of Granada, C/ Fuentenueva s/n, E-18071, Granada, Spain.

There is a large amount of literature relating to multivariate analytical methods using liquid chromatography together with multivariate chemometric/data mining methods in the food science field. Nevertheless, dating the obtained results cannot be compared as they are based on data acquired by a particular analytical instrument, thus they are instrument-dependant. Therefore, this creates difficulties in generating a database large enough to gather together all the variability of the samples. Read More

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