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Micellar Liquid Chromatography

Ester Hernández-Corroto, Mª Luisa Marina, Mª Concepción García
This work proposes a method to separate proteins and polyphenols in a food byproduct with high bioactive properties and demonstrate by high performance liquid chromatography tandem mass spectrometry its efficiency. Bioactive substances were extracted using high intensity focused ultrasounds. Resulting extract (SR) was submitted to a step for the purification of proteins and to obtain a protein isolate (PI). Both extracts (SR and PI) were digested using two different enzymes (alcalase and thermolysin). Antioxidant, hypocholesterolemic, and antihypertensive properties of hydrolysates were explored...
February 7, 2019: Journal of Chromatography. A
Giuseppe Ermondi, Giulia Caron
Improving the interpretability of multivariate QSPR models is a major issue in modern drug discovery. In this study we applied three strategies to model and deconvolute the balance of intermolecular forces governing log KW SDS , a chromatographic descriptor of potential relevance in the prediction of ADME phenomena. A dataset of 77 compounds was set-up and an ad hoc pool of VS+ descriptors calculated. The data matrix was firstly submitted to a PCA run for a preliminary analysis and outliers detection. To model and interpret log KW SDS three chemoinformatic approaches implementing either variable selection or grouping tools were used: a) MLR and GA, b) PLSR combined with BR analysis and c) MBPLSR...
February 15, 2019: Molecular Informatics
Hany W Darwish, Ahmed H Bakheit, Nasser S Al-Shakliah, Ibrahim A Darwish
A highly sensitive and accurate novel response surface methodology (RSM)-assisted micellar enhanced synchronous spectrofluorimetric method was developed and validated for determination of vandetanib (VDB) in tablets, human plasma and urine. The method relied on enhancement of the fluorescence behavior of VDB in polyoxyethylene hydrogenated castor oil 40 (HCO 40) micellar medium and measuring the fluorescence using synchronous scan approach (Δλ = 50 nm). Key factors affecting VDB fluorescence were optimized by RSM using Box-Behnken design...
January 16, 2019: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Seishi Shimizu, Steven Abbott, Katarzyna Adamska, Adam Voelkel
Determinations of solute-cosolute interactions from chromatography have often resulted in problems, such as the "antibinding" (or a negative binding constant) between the solute and micelle in micellar liquid chromatography (MLC) or indeterminacy of salt-ligand binding strength in high-performance affinity chromatography (HPAC). This shows that the stoichiometric binding models adopted in many chromatographic analyses cannot capture the non-specific nature of solvation interactions. In contrast, an approach using statistical thermodynamics handles these complexities without such problems and directly links chromatographic data to, for example, solubility data via a universal framework based on Kirkwood-Buff integrals (KBI) of the radial distribution functions...
January 15, 2019: Analyst
Ning Li, N M El Zahar, Jack G Saad, Erik R E van der Hage, Michael G Bartlett
Alkylamines are commonly used to improve both chromatographic and mass spectral performance of electrospray ionization liquid chromatography mass spectrometry based methods for the analysis of oligonucleotides. Recently several new alkylamines have been introduced to enhance the electrospray mass spectral response for oligonucleotides; however, the chromatographic properties of these new alkylamines have not been rigorously assessed. We have investigated the retention, peak width, resolution and general chromatographic performance of fifteen different alkylamines for the separation of a model DNA, RNA and an antisense therapeutic oligonucleotide...
October 25, 2018: Journal of Chromatography. A
Hiroshi Habe, Toshiaki Taira, Tomohiro Imura
Bacillus licheniformis NBRC 104464 produces a cyclic lipopeptide different from surfactin. After we performed liquid chromatography fractionation and purification, we used structural analyses to identify the cyclic lipopeptide as lichenysin. Surface tension measurements of lichenysin sodium salt in water yielded a critical micelle concentration (CMC) of 1.0×10-5 M. The surface tension at the CMC was 28.9 mN/m. Comparative analysis of Ca2+ -influenced micellar aggregation of lichenysin and surfactin revealed that the formation rate of the lichenysin-Ca2+ complex aggregate remained low up to a [Ca2+ ]/[lichenysin] molar ratio of 80, whereas the surfactin-Ca2+ complex formed micellar aggregates at the same molar ratio...
2018: Journal of Oleo Science
Mirjam Kummer, Nela Šestáková, Regula Theurillat, Uyen Huynh-Do, Andrea Endimiani, Parham Sendi, Wolfgang Thormann
Cefepime monitoring in urine by micellar electrokinetic capillary chromatography with UV detection and liquid chromatography coupled to mass spectrometry via electrospray ionization is described. For micellar electrokinetic capillary chromatography, sample preparation comprised urine dilution and dodecyl-sulfate protein precipitation at pH 4.5, whereas diluted urines were analyzed in the other assay. Both approaches provided suitable conditions for cefepime analysis in urines of healthy volunteers that were spiked with cefepime...
November 2018: Journal of Separation Science
Feng Li, Huixia Zhang, Miao He, Jinhui Liao, Nianhang Chen, Yan Li, Simon Zhou, Maria Palmisano, Alex Yu, Manjunath P Pai, Hebao Yuan, Duxin Sun
Previous studies have shown that different paclitaxel formulations produce distinct anticancer efficacy and safety profiles in animals and humans. This study aimed to investigate the distinct pharmacokinetics and tissue distribution of various nanoformulations of paclitaxel, which may translate into potential differences in safety and efficacy. Four nanoparticle formulations ( nab-paclitaxel, mouse albumin nab-paclitaxel [m -nab-paclitaxel], micellar paclitaxel, and polymeric nanoparticle paclitaxel) as well as solvent-based paclitaxel were intravenously administered to mice...
October 1, 2018: Molecular Pharmaceutics
Federica Ianni, Lucia Pucciarini, Andrea Carotti, Serena Natalini, Gulnara Z Raskildina, Roccaldo Sardella, Benedetto Natalini
Chiral ligand-exchange chromatography is one of the elective strategies for the direct enantioresolution of small chelating compounds: amino acids, diamines, amino alcohols, diols, small peptides, etc. Unlike other methods, the interaction between chiral selector and analyte enantiomers is mediated by a cation, thus producing diastereomeric ternary complexes. Two main approaches are conventionally applied in chiral ligand-exchange chromatography. The first relies upon chiral stationary phases where the chiral selector is either covalently immobilized or physically adsorbed onto suitable packing materials (coated phases)...
August 27, 2018: Journal of Separation Science
Xuanxuan Wang, Xiao Li, Yuxiu Xiao
A novel hexafluoroisopropanol (HFIP)-octanol supramolecular solvent (SUPRAS) based dispersive liquid-liquid microextraction (DLLME) method was developed for the determination of 2,6-dimethylaniline (2,6-DMA) in lidocaine hydrochloride injection coupled with high performance liquid chromatography-ultraviolet detection (HPLC-UV). n -Octanol was selected as extraction solvent while HFIP was served as dispersing agent, self-assembly inducer of n -octanol as well as density-regulating agent of n -octanol. The HFIP-octanol SUPRAS displays reverse micellar aggregate structures (2-6 μm) with hydrophilic inner cores and is located in the bottom phase of the system after phase separation, which not only facilitates the efficient extraction and enrichment of polar 2,6-DMA, but also simplifies the extraction process...
March 8, 2018: Se Pu, Chinese Journal of Chromatography
Juan Peris-Vicente, Jesús Javier Iborra Millet, Jaume Albiol-Chiva, Samuel Carda-Broch, Josep Esteve-Romero
BACKGROUND: Micellar liquid chromatography - fluorescence detection was used to determine the antibiotics flumequine, marbofloxacin, difloxacin and sarafloxacin in porcine, bovine, poultry, ovine, caprine, rabbit and equine meat, to verify their compliance with the EU Regulation 37/2010 about the occurrence of veterinary drugs in food. RESULTS: The analytes were isolated from matrix by ultrasonication-assisted leaching in a micellar solution, and the supernatant was filtered and directly injected...
August 17, 2018: Journal of the Science of Food and Agriculture
Dina S Shokry, Laura J Waters, Gareth M B Parkes, John C Mitchell
Micellar liquid chromatography is a popular method used in the determination of a compound's lipophilicity. This study describes the use of the obtained micelle-water partition coefficient (log Pmw ) by such a method in the prediction of human intestinal absorption (HIA). As a result of the close resemblance of the novel composition of the micellar mobile phase to that of physiological intestinal fluid, prediction was deemed to be highly successful. The unique micellar mobile phase consisted of a mixed micellar mixture of lecithin and six bile salts, i...
July 30, 2018: Biomedical Chromatography: BMC
Isabel Cristina Celerino de Moraes Porto, Dayse Chaves Cardoso de Almeida, Gabriela Vasconcelos Calheiros de Oliveira Costa, Tayná Stéphanie Sampaio Donato, Letícia Moreira Nunes, Ticiano Gomes do Nascimento, José Marcos Dos Santos Oliveira, Carolina Batista da Silva, Natanael Barbosa Dos Santos, Maria Luísa de Alencar E Silva Leite, Irinaldo Diniz Basílio-Júnior, Camila Braga Dornelas, Pierre Barnabé Escodro, Eduardo Jorge da Silva Fonseca, Regianne Umeko Kamiya
BACKGROUND: Propolis is a natural substance produced by bees and is known to have antimicrobial activity. Our aim was to evaluate the antimicrobial effect of micellar nanocomposites loaded with an ethyl acetate extract of Brazilian red propolis as a cavity cleaning agent and its influence on the color and microtensile bond strength (μTBS) of the dentin/resin interface. METHODS: An ultra-performance liquid chromatography coupled with a diode array detector (UPLC-DAD) assay was used to determine the flavonoids and isoflavones present in an ethyl acetate extract of Brazilian red propolis (EARP) and micellar nanocomposites loaded with EARP (MNRP)...
July 18, 2018: BMC Complementary and Alternative Medicine
Fawzia Ibrahim, Asmaa Kamal El-Deen, Kuniyoshi Shimizu
In the present study, we compare the performance of two reversed-phase liquid chromatographic approaches using different eluents either conventional hydro-organic eluent or micellar one for simultaneous estimation of hydrocortisone acetate and pramoxine hydrochloride in presence of their degradants and process-related impurities; hydrocortisone and 4-butoxyphenol, respectively. For conventional reversed-phase liquid chromatography (RPLC), separation of the studied compounds was completed on an Inertsil ODS 3-C18 column (150 mm × 4...
July 2018: Journal of Food and Drug Analysis
Sarah Nasser, Paulo De Sa Peixoto, Anne Moreau, Thomas Croguennec, Fabrice Bray, Christian Rolando, Frédéric J Tessier, Alain Hédoux, Guillaume Delaplace
During storage, a series of changes occur for dairy powders, such as protein lactosylation and the formation of Maillard reaction products (MRPs), leading to powder browning and an increase of insoluble matter. The kinetics of protein lactosylation and MRP formation are influenced by the lactose content of the dairy powder. However, the influence of lactose in the formation of insoluble matter and its role in the underlying mechanisms is still a subject of speculation. In this study, we aim to investigate the role of lactose in the formation of insoluble matter in a more comprehensive way than the existing literature...
October 3, 2018: Journal of Agricultural and Food Chemistry
Ester Peris-García, Jorge Rodríguez-Martínez, Juan J Baeza-Baeza, María Celia García-Alvarez-Coque, María José Ruiz-Angel
Most reports in reversed-phase liquid chromatography (RPLC) with micellar mobile phases make use of the anionic sodium dodecyl sulfate. This surfactant masks efficiently the silanol groups that are the origin of the poor efficiencies and tailing peaks observed for basic compounds in conventional RPLC. However, it has the handicap of yielding excessive retention, which forces the addition of an organic solvent to reduce the retention times to practical values. Other surfactants, such as the non-ionic polyoxyethylene(23)lauryl ether (Brij-35), are rarely used...
June 19, 2018: Analytical and Bioanalytical Chemistry
Jessica Fiori, Benedetta Pasquini, Claudia Caprini, Serena Orlandini, Sandra Furlanetto, Roberto Gotti
Monomeric catechins are important compounds in green tea accounting for potential bioactivity against a wide range of diseases. Besides catechins, l-Theanine (γ-glutamylethylamide), a characteristic amino acid in tea leaves, has become a further focus of the phytochemical research for the reported beneficial effects mainly on cognitive performance, emotional state and sleep quality. In the present study has been developed a CD-MEKC method based on sodium dodecyl sulfate (SDS) and Heptakis (2,6-di-O-methyl)-β-cyclodextrin for the separation of six major green tea catechins and enantiomers of theanine...
August 10, 2018: Journal of Chromatography. A
F Belal, F Ibrahim, Z A Sheribah, H Alaa
A method based on micellar liquid chromatography to quantify levodopa, carbidopa and entacapone in plasma is reported. The sample pretreatment was a simple dilution in a pure micellar solution then filtration and direct injection, without requiring extraction or purification steps. The three drugs were resolved from the matrix in 7 min, using an aqueous solution of 0.1 M sodium dodecyl sulphate-10% n-propanol-0.3 tiethylamine, adjusted at pH 2.8 with 0.02 M orthophosphoric acid as mobile phase, running under isocratic mode at 1...
August 1, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Samereh Ranjbar Bandforuzi, Mohammad Reza Hadjmohammadi
The extraction of phthalate esters (PEs) from aqueous matrices using two-phase solvent bar microextraction by organic micellar phase was investigated. A short hollow fiber immobilized with reverse micelles of Brij 35 surfactant in 1-octanol was served as the solvent bar for microextraction. Experimental results show that the extraction efficiency were much higher using two-phase solvent bar microextraction based on non-ionic surfactant than conventional two-phase solvent bar microextraction because of a positive effect of surfactant-containing extraction phase in promoting the partition process by non-ionic intermolecular forces such as polar and hydrophobicity interactions...
August 3, 2018: Journal of Chromatography. A
Qing Yang, Beibei Chen, Man He, Bin Hu
A rapid, simple, and effective method has been developed for the determination of seven triazine herbicides (terbutryn, prometryn, ametryn, prometon, propazine, atrazine, simazine) by coupling off-line hollow fiber liquid liquid liquid microextraction (HF-LLLME) with on-line sweeping micellar electrokinetic chromatography (sweeping-MEKC). In HF-LLLME, seven target triazines in hydrophobic form were extracted from the sample solution into decane impregnated in the pores of the hollow fiber, and then back-extracted into 1 mol L-1 H3 PO4 inside the hollow fiber lumen...
August 15, 2018: Talanta
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