2,838 results match your criteria products rp-hplc


New stability chiral RP-HPLC method for degradation products determination in midodrine hydrochloride.

Drug Dev Ind Pharm 2021 Apr 5:1-21. Epub 2021 Apr 5.

Department of Pharmaceutical Analysis, JSS Academy of Higher Education and Research, JSS College of Pharmacy, Ooty, Nilgiris, Tamil Nadu, India.

Enantiomeric resolution of the drug and complete separation from its degradation products were successfully achieved on a PAK IG-3 (150 × 4.6 mm i.d, 3 µm particle size) column, using UV detector at a wavelength of 290 nm, with mobile phase consisting of acetonitrile, 20 mM ammonium bicarbonate at the ratio of 95:05 (v/v), and a flow rate of 0. Read More

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Pepsin Hydrolysis of Orange By-Products for the Production of Bioactive Peptides with Gastrointestinal Resistant Properties.

Foods 2021 Mar 23;10(3). Epub 2021 Mar 23.

Instituto de Agroquímica y Tecnología de Alimentos (CSIC), Avenue Agustín Escardino 7, Paterna, 46980 Valencia, Spain.

Recently, the use of bioactive compounds in improving human health has received more attention. The aim of the present study was to hydrolyze orange seed proteins using pepsin enzyme to obtain bioactive peptides as well as to study the stability of such activity after simulated gastrointestinal digestion conditions. The method was optimized using different enzyme concentrations from 1% to 3%, hydrolysis times between 2 and 5 h, and an optimal temperature of 33 °C. Read More

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Maillard Reaction Products in Gluten-Free Bread Made from Raw and Roasted Buckwheat Flour.

Molecules 2021 Mar 4;26(5). Epub 2021 Mar 4.

Department of Food Technology of Plant Origin, Poznań University of Life Sciences, 31 Wojska Polskiego St., 60-624 Poznań, Poland.

The formation of Maillard reaction products (MRPs) in gluten-free bread made from roasted and raw buckwheat flour was examined. The levels of phenolic compounds such as flavonoids (catechin, naringenin, quercetin, rutin, and others) and phenolic acids (like 4-hydroxybenzoic, caffeic, dihydroxybenzoic, ferulic, gallic, syringic, vanillic, and -coumaric) were measured using reversed-phase ultra-high performance liquid chromatography-electrospray ionization mass spectrometry (RP-UHPLC-ESI-MS). Early and advanced Maillard reaction products were analyzed using HPLC, whereas spectrofluorimetric analysis was used to determine the levels of fluorescent intermediate compounds (FIC). 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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A Metabolomics and Molecular Networking Approach to Elucidate the Structures of Secondary Metabolites Produced by Strains.

Front Chem 2021 16;9:633870. Epub 2021 Mar 16.

Department of Microbiology, Faculty of Science, Stellenbosch University, Stellenbosch, South Africa.

An integrated approach that combines reverse-phase high-performance liquid chromatography (RP-HPLC), electrospray ionization mass spectrometry, untargeted ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS) and molecular networking (using the Global Natural Products Social molecular network platform) was used to elucidate the metabolic profiles and chemical structures of the secondary metabolites produced by pigmented (P1) and non-pigmented (NP1) () strains. Tandem mass spectrometry-based molecular networking guided the structural elucidation of 18 compounds for the P1 strain (including 6 serratamolides, 10 glucosamine derivatives, prodigiosin and serratiochelin A) and 15 compounds for the NP1 strain (including 8 serratamolides, 6 glucosamine derivatives and serratiochelin A) using the MS fragmentation profiles. The serratamolide homologues were comprised of a peptide moiety of two L-serine residues (cyclic or open-ring) linked to two fatty acid chains (lengths of C, C, or C). Read More

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[Research on chemical constituents from Artemisia annua Ⅰ].

Zhongguo Zhong Yao Za Zhi 2021 Mar;46(5):1160-1167

Institute of Traditional Chinese Medicine and Natural Products,College of Pharmacy,Jinan University Guangzhou 510632,China.

Chemical constituents were isolated and purified from the water extract of Artemisia annua by column chromatography of HP-20 macroporous resin, silica gel, ODS, Sephadex LH-20, HW-40, and semi-preparative RP-HPLC. Their structures were elucidated by physicochemical properties and spectral analyses. As a result, Fifteen compounds were isolated and identified as vitexnegheteroin M(1), sibricose A5(2), securoside A(3), citrusin D(4), annphenone(5), E-melilotoside(6), esculetin(7), scopoletin-7-O-β-D-glucoside(8), eleutheroside B_1(9), chrysosplenol D(10), patuletin-3-O-β-D-glucopyranoside(11), quercetin-7-O-β-D-glucoside(12), rutin(13), apigenin 6,8-di-C-β-D-glucopyranoside(14), isoschaftoside(15), among them, compounds 1-4 were identified from Artemisia for the first time. 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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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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Nonclinical Toxicological Studies of Brazilian Red Propolis and Its Primary Botanical Source .

Chem Res Toxicol 2021 Mar 15. Epub 2021 Mar 15.

Laboratory of Pharmacognosy, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Av. do Café S/N, Ribeirão Preto, SP 14040-930, Brazil.

Propolis is one of the most widely used products in traditional medicine. One of the most prominent types of Brazilian propolis is the red one, whose primary botanical source is (L.) Taub. Read More

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Near Infrared Spectroscopy as a PAT tool for monitoring and control of protein and excipient concentration in ultrafiltration of highly concentrated antibody formulations.

Int J Pharm 2021 Mar 9;600:120456. Epub 2021 Mar 9.

Department of Chemical Engineering, Indian Institute of Technology Delhi, 110016 Hauz Khas, India. Electronic address: http://www.biotechcmz.com.

Excipient concentrations are critical quality attributes of monoclonal antibody (mAb) drug products and affect their safety and efficacy. In manufacturing processes, mAb products are formulated into the buffer containing the desired excipients using ultrafiltration (UF) and diafiltration (DF). Control of excipient concentrations is a challenge during high concentration UF due to electrostatic interactions which lead to excipient concentration drifts. Read More

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A Pipeline towards the Biochemical Characterization of the GT14 Family.

Int J Mol Sci 2021 Jan 29;22(3). Epub 2021 Jan 29.

Sino-Australia Plant Cell Wall Research Centre, The State Key Laboratory of Subtropical Silviculture, College of Forestry and Biotechnology, Zhejiang A & F University, Lin'an 311300, China.

Glycosyltransferases (GTs) catalyze the synthesis of glycosidic linkages and are essential in the biosynthesis of glycans, glycoconjugates (glycolipids and glycoproteins), and glycosides. Plant genomes generally encode many more GTs than animal genomes due to the synthesis of a cell wall and a wide variety of glycosylated secondary metabolites. The genome is predicted to encode over 573 GTs that are currently classified into 42 diverse families. Read More

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January 2021

Screening, Optimization, and Bioavailability Research of Natural Deep Eutectic Solvent Extracts from .

Molecules 2021 Jan 31;26(3). Epub 2021 Jan 31.

College of Life Science, Zhejiang Chinese Medical University, Hangzhou 310057, China.

Natural deep eutectic solvent (NaDES) is generally considered as a greener alternative to fossil solvent, with great potential in various areas. In the present work, 25 different NaDESs were screened for the extraction of puerarin (PUE) and its two natural derivatives from (RP). As the main isoflavone in RP, PUE has a wide range of biological activities. Read More

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January 2021

Antagonistic Activity of Antimicrobial Metabolites Produced from Seaweed-Associated Bacillus amyloliquefaciens MTCC 10456 Against Malassezia spp.

Probiotics Antimicrob Proteins 2021 Feb 1. Epub 2021 Feb 1.

Praj-Matrix - R&D Centre (Division of Praj Industries Limited) 402/403/1098, Urawade, Pirangut, Mulshi, Pune, 412115, Maharashtra, India.

Members of the genus Malassezia are known to be opportunistic pathogens responsible for causing skin disorders such as seborrheic dermatitis or dandruff, pityriasis versicolor, folliculitis, atopic dermatitis, and psoriasis. Due to the side effects caused by prolonged use of current topical antifungal agents, development of an alternative treatment is necessary. Fermentative production of antimicrobial metabolites from Bacillus amyloliquefaciens MTCC 10456 was carried out, and their antagonistic activity against Malassezia furfur and Malassezia globosa was evaluated. Read More

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February 2021

Dissolution Profile at Different Biological pH Conditions of Hydroxychloroquine Sulfate Tablets Is Available for the Treatment of COVID-19.

Front Mol Biosci 2020 14;7:613393. Epub 2021 Jan 14.

Discipline of Pharmacy, Graduate School of Health, University of Technology Sydney, Ultimo, NSW, Australia.

Hydroxychloroquine sulfate is one of an extensive series of 4-aminoquinolines with antimalarial activity. Moreover, it is used for the treatment of rheumatoid arthritis. Sometimes, hydroxychloroquine sulfate is beneficial for the treatment of autoimmune diseases. Read More

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January 2021

Angiotensin-I converting enzyme inhibitory peptide derived from the shiitake mushroom ().

J Food Sci Technol 2021 Jan 15;58(1):85-97. Epub 2020 May 15.

Research Unit in Bioconversion/Bioseparation for Value-Added Chemical Production, Institute of Biotechnology and Genetic Engineering, Chulalongkorn University, 254 Phayathai Road, Wangmai, Pathumwan, Bangkok, 10330 Thailand.

Abstract: Angiotensin-I converting enzyme (ACE) inhibitors are widely used to control hypertension. In this study, protein hydrolysates from shiitake mushroom were hydrolyzed to prepare ACE-inhibitory peptides. Optimum process conditions for the hydrolysis of shiitake mushrooms using Alcalase were optimized using response surface methodology. Read More

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January 2021

Exploitation of HPLC Analytical Method for Simultaneous Determination of Six Principal Unsaturated Fatty Acids in Based on Quantitative Analysis of Multi-Components by Single-Marker (QAMS).

Molecules 2021 Jan 18;26(2). Epub 2021 Jan 18.

School of Pharmaceutical Sciences, Jilin University, Changchun 130021, Jilin, China.

As one of the featured products in northeast China, has been widely used as a nutritious food, which contains a variety of bioactive unsaturated fatty acids (UFAs). It is necessary to establish a scientific and reliable determination method of UFA contents in . In this work, six principal UFAs in , namely eicosapentaenoic acid (EPA), linolenic acid (ALA), docosahexaenoic acid (DHA), arachidonic acid (ARA), linoleic acid (LA) and oleic acid (OA), were identified using UPLC-MS/MS. Read More

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January 2021

Oxidative degradation profile studies of tavaborole by a validated stability indicating RP-UPLC method: Isolation and characterization of novel degradant using 2D-NMR and HRMS.

Biomed Chromatogr 2021 Jan 16:e5070. Epub 2021 Jan 16.

Analytical Research and Development Laboratory, GVK Biosciences Private Limited, No. 28A, IDA Nacharam, Hyderabad, Telangana, India.

The current research work reports a study on the degradation profile of tavaborole, which is an oxaborole antifungal drug used to treat infections in the toenails. This work also reports the chemical stability of tavaborole in different stress conditions along with the isolation and characterization of degradation products by high-resolution mass spectrometry and two-dimensional nuclear magnetic resonance techniques. A sensitive and reproducible stability-indicating ultra-performance liquid chromatography method was developed and validated for quantification of tavaborole bulk drug in the presence of degradation products. Read More

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January 2021

Quality and Stability Profile Assessment of the Recent Antidiabetic Omarigliptin by Using Different Chromatographic Methods.

J Chromatogr Sci 2021 Jan 13. Epub 2021 Jan 13.

Analytical Chemistry Department, Faculty of Pharmacy, Cairo University, Kasr el Aini Street, 11562, Cairo, Egypt.

In a contribution to stability profiling of the recent antidiabetic drug, omarigliptin (OMR), two stability-indicating chromatographic methods were developed and validated. Stability profiling was performed for OMR under different stress conditions as acidic, alkaline, oxidative, photolytic and thermal degradations. Structures elucidation to all formed degradation products were identified using IR and mass spectrometry. Read More

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January 2021

A QuEChERS-HPLC-MS/MS Method with Matrix Matching Calibration Strategy for Determination of Imidacloprid and Its Metabolites in (Crayfish) Tissues.

Molecules 2021 Jan 7;26(2). Epub 2021 Jan 7.

Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China.

We developed a method for determination of imidacloprid and its metabolites 5-hydroxy imidacloprid, olefin imidacloprid, imidacloprid urea and 6-chloronicotinic acid in (crayfish) tissues using quick, easy, cheap, effective, rugged, and safe (QuEChERS) and high-performance liquid chromatography-triple quadrupole mass spectrometry. Samples (plasma, cephalothorax, hepatopancrea, gill, intestine, and muscle) were extracted with acetonitrile containing 0.1% acetic acid and cleaned up using a neutral alumina column containing a primary secondary amine. Read More

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January 2021

Chemical profiling and separation of bioactive secondary metabolites in Maca (Lepidium peruvianum) by normal and reverse phase thin layer chromatography coupled to desorption electrospray ionization-mass spectrometry.

J Mass Spectrom 2021 Feb;56(2):e4690

Centre for Research in Mass Spectrometry, Department of Chemistry, York University, Toronto, Ontario, Canada.

Maca is a Peruvian tuberous root of the Brassicaceae family grown in the central Andes between altitudes of 4000 and 4500 m. The medicinal plant is a nutraceutical with important biological activities and health effects. In this study, we report a rapid high-performance thin layer chromatography (HPTLC)-(-)desorption electrospray ionization (DESI)-mass spectrometry (MS) method to profile and separate intact glucosinolates without prior biochemical modifications from the hydromethanolic extracts of two phenotypes, red and black Maca (Lepidium peruvianum) seeds. Read More

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February 2021

Bifidobacterium animalis F1-7 in combination with konjac glucomannan improves constipation in mice via humoral transport.

Food Funct 2021 Jan 4;12(2):791-801. Epub 2021 Jan 4.

College of Food Science and Engineering, Ocean University of China, Qingdao, 266000, China.

Probiotics and natural products can promote humoral transport and effectively relieve intestinal motility. This study investigated the effects of probiotics in combination with konjac glucomannan (KGM) and an aqueous extract of Prunus persica on constipation. The growth promotion effect of these natural products on probiotics was investigated using co-culture in vitro. Read More

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January 2021

Plant Extract and Herbal Products as Potential Source of Sorbent for Analytical Purpose: An Experimental Study of Morphine and Codeine Determination Using HPLC and LC-MSMS.

J Chromatogr Sci 2021 Jan 4. Epub 2021 Jan 4.

Medical Toxicology Research Center, Mashhad University of Medical Sciences, Mashhad 9177948564, Iran.

Solid-phase microextraction (SPME) is an analytical method for microextraction of analytes, in which the analytes bind to the sorbent on the surface of the SPME fiber. Many types of chemical agents are used as sorbent; however, many of these sorbents cause secondary contamination or are not cost-effective. Here, aqueous extract of Ferula gummosa was evaluated as potential source of sorbent for simultaneous microextraction of morphine and codeine. Read More

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January 2021

Ameliorative potential of Adhatoda vasica against anti-tubercular drugs induced hepatic impairments in female Wistar rats in relation to oxidative stress and xeno-metabolism.

J Ethnopharmacol 2021 Apr 31;270:113771. Epub 2020 Dec 31.

Department of Zoology, Panjab University, Chandigarh, 160014, India. Electronic address:

Ethnopharmacological Relevance: Adhatoda vasica Nees is widely used herb of indigenous system to treat various ailments especially upper respiratory tract infections. Not only, anti-tubercular efficacy of crude extract and phytoconstituents of A. vasica has been documented but its hepatoprotective role against various drugs mediated hepatic alterations in different animal models has also been observed. Read More

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Comprehensive Workflow for Mapping Disulfide Linkages Including Free Thiols and Error Checking by On-Line UV-Induced Precolumn Reduction and Spiked Control.

Anal Chem 2021 01 30;93(3):1544-1552. Epub 2020 Dec 30.

Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan.

Mapping highly complicated disulfide linkages and free thiols via liquid chromatography-tandem mass spectrometry (LC-MS) is challenging because of the difficulties in optimizing sample preparation to acquire critical MS data and detecting mispairings. Herein, we report a highly efficient and comprehensive workflow using an on-line UV-induced precolumn reduction tandem mass spectrometry (UV-LC-MS) coupled with two-stage data analysis and spiked control. UV-LC-MS features a gradient run of acetonitrile containing a tunable percentage of photoinitiators (acetone/alcohol) that drives the sample to the MS through a UV-flow cell and reverse phase column to separate UV-induced products for subsequent fragmentation via low energy collision-induced dissociation. Read More

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January 2021

Structural Analysis of Oxidized Cerebrosides from the Extract of Deep-Sea Sponge sp.: Occurrence of Amide-Linked Allylically Oxygenated Fatty Acids.

Molecules 2020 Dec 21;25(24). Epub 2020 Dec 21.

G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch of the Russian Academy of Sciences, Pr. 100 let Vladivostoku 159, 690022 Vladivostok, Russia.

The structural elucidation of primary and secondary peroxidation products, formed from complex lipids, is a challenge in lipid analysis. In the present study, rare minor oxidized cerebrosides, isolated from the extract of a far eastern deep-sea glass sponge, sp., were analyzed as constituents of a multi-component RP-HPLC (high-performance liquid chromatography on reversed-phase column) fraction using NMR (nuclear magnetic resonance) spectroscopy, mass spectrometry, GC (gas chromatography), and chemical transformations (including hydrogenation or derivatization with dimethyl disulfide before hydrolysis). Read More

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December 2020

Identification and Antihypertension Study of Novel Angiotensin I-Converting Enzyme Inhibitory Peptides from the Skirt of Fermented with .

J Agric Food Chem 2021 Jan 24;69(1):146-158. Epub 2020 Dec 24.

College of Life Sciences, Qingdao University, Qingdao 266071, China.

The aim of this study was to isolate the angiotensin I-converting enzyme (ACE) inhibitory peptides from the skirt of fermented with and to explore the antihypertension effect through studies. ACE inhibitory peptides were purified from the fermentation mixture by ultrafiltration, gel filtration chromatography, and reversed-phase high-performance liquid chromatography sequentially. The amino acids' sequence of the five novel ACE inhibitory peptides were identified by liquid chromatography-tandem mass spectrometry. Read More

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January 2021

Charge variant analysis of protein-based biopharmaceuticals using two-dimensional liquid chromatography hyphenated to mass spectrometry.

J Chromatogr A 2021 Jan 8;1636:461786. Epub 2020 Dec 8.

Pharmaceutical (Bio-)Analysis, Institute of Pharmaceutical Sciences, University of Tübingen, Auf der Morgenstelle 8, 72076 Tübingen, Germany. Electronic address:

The profile of charge variants represents an important critical quality attribute of protein-based biopharmaceuticals, in particular of monoclonal antibodies, and must therefore becontrolled. In this work, 2D-LC methods for charge variant analysis were developed using a strong cation-exchange chromatography (SCX) as first dimension (D) separation. Non-porous SCX (3 µm) particle columns and different mobile phases were evaluated using a test mixture of some standard proteins of different size and pI (comprising myoglobin, bovine serum albumin, cytochrome c, lysozyme and β-lactoglobulin) and two monoclonal IgG1 antibodies (NIST mAb and Secukinumab). Read More

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January 2021

Flavonol Glycosides: In Vitro Inhibition of DPPIV, Aldose Reductase and Combating Oxidative Stress are Potential Mechanisms for Mediating the Antidiabetic Activity of .

Molecules 2020 Dec 11;25(24). Epub 2020 Dec 11.

Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt.

Diabetes is a major health problem that is associated with high risk of various complications. Medicinal plants hold great promise against diabetes. The traditional use of as an antidiabetic agent was correlated to its flavonol glycosides content. Read More

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December 2020