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https://www.readbyqxmd.com/read/27923199/the-importance-of-vial-composition-in-hplc-analysis-an-unusual-case-of-phosphorous-pseudorotation
#1
Rebecca Arvary, Ian Mangion
Glass HPLC vials are ubiquitous in analytical laboratories and vendors have developed many varieties to meet the various needs of scientists. As such there may be multiple types of vials being used simultaneously in a single laboratory without much consideration as to which is best suited for analytical method development and validation. This study highlights the possibility of vial composition as a potential factor that impacts solution stability. Here we describe a case where the type of HPLC vial used results in an interesting phosphorous pseudorotation driven by the mild alkalinity of glass...
October 6, 2016: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/27921399/antioxidant-and-antidiabetic-properties-of-tartary-buckwheat-rice-flavonoids-after-in-vitro-digestion
#2
Tao Bao, Ye Wang, Yu-Ting Li, Vemana Gowd, Xin-He Niu, Hai-Ying Yang, Li-Shui Chen, Wei Chen, Chong-de Sun
Oxidative stress and diabetes have a tendency to alter protein, lipid, and DNA moieties. One of the strategic methods used to reduce diabetes-associated oxidative stress is to inhibit the carbohydrate-digesting enzymes, thereby decreasing gastrointestinal glucose production. Plant-derived natural antioxidant molecules are considered a therapeutic tool in the treatment of oxidative stress and diabetes. The objective of this study was to identify tartary buckwheat rice flavonoids and evaluate the effect of in vitro digestion on their antioxidant and antidiabetic properties...
2016: Journal of Zhejiang University. Science. B
https://www.readbyqxmd.com/read/27921291/evaluation-of-capillary-electrophoresis-for-the-analysis-of-rooibos-and-honeybush-tea-phenolics
#3
William J Arries, Andreas G J Tredoux, Dalene de Beer, Elizabeth Joubert, André de Villiers
Rooibos and honeybush are popular herbal teas produced from the shrubs of Aspalathus linearis and Cyclopia spp., respectively, which are indigenous to South Africa. Both herbal teas are rich in polyphenols and their consumption is associated with several health benefits, partly ascribed to their phenolic constituents. Quantification of phenolics in extracts and teas for quality control and research purposes is generally performed using HPLC, although dedicated and often species-specific methods are required...
December 6, 2016: Electrophoresis
https://www.readbyqxmd.com/read/27920887/preliminary-study-on-cost-effective-l-tryptophan-production-from-indole-and-l-serine-by-e-coli-cells
#4
Tahereh Sadeghiyan-Rizi, Jamshid Fooladi, Sima Sadrai
BACKGROUND: L-tryptophan is used widespread in the pharmaceutical industry. The majority of L-Trp production depends on microbial processes that produce L-tryptophan from indole and L-serine. These processes are very costly due to the costs of precursors, especially L-serine. Use of inexpensive substitutions as the L-serine source of L-tryptophan production enables us to reach a cost-effective process. In this paper, effect of Triton X-100 on L-Trp production and the ability to use Iranian cane molasses as inexpensive L-serine source was investigated...
October 2016: Avicenna Journal of Medical Biotechnology
https://www.readbyqxmd.com/read/27920527/pharmacokinetics-and-safety-of-dts-108-a-human-oligopeptide-bound-to-sn-38-with-an-esterase-sensitive-cross-linker-in-patients-with-advanced-malignancies-a-phase-i-study
#5
Romain Coriat, Sandrine J Faivre, Olivier Mir, Chantal Dreyer, Stanislas Ropert, Mohammed Bouattour, Robert Desjardins, François Goldwasser, Eric Raymond
BACKGROUND: DTS-108 is a hydrosoluble prodrug, where the SN-38 moiety is covalently linked to a 20-amino acid vector peptide by a specific esterase-sensitive cross-linker, releasing 7-ethyl-10-hydroxycampthotecin (SN-38) by esterase bond cleavage. METHODS: The pharmacokinetics of DTS-108, adverse events graded according to NCI-CTCv3.1, dose-limiting toxicities at cycle 1, the maximum tolerated dose (MTD), and the recommended Phase II dose (RP2D) of intravenous DTS-108 (1-2 hours) every 2 weeks were evaluated in a first-in-human Phase I study in patients with advanced/metastatic carcinomas, according to an accelerated dose escalation design...
2016: International Journal of Nanomedicine
https://www.readbyqxmd.com/read/27919703/prediction-and-mechanism-elucidation-of-analyte-retention-on-phospholipid-stationary-phases-iam-hplc-by-in-silico-calculated-physico-chemical-descriptors
#6
Giacomo Russo, Lucia Grumetto, Francesco Barbato, Giulio Vistoli, Alessandro Pedretti
The present study proposes a method for an in silico calculation of phospholipophilicity. Phospholipophilicity is intended as the measure of analyte affinity for phospholipids; it is currently assessed by HPLC measures of analyte retention on phosphatidylcholine-like stationary phases (IAM - Immobilized Artificial Membrane) resulting in log kW(IAM) values. Due to the amphipathic and electrically charged nature of phospholipids, retention on these stationary phases results from complex mechanisms, being affected not only by lipophilicity (as measured by n-octanol/aqueous phase partition coefficients, log P) but also by the occurrence of polar and/or electrostatic intermolecular interaction forces...
December 2, 2016: European Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/27919520/the-nanjing-glycated-hemoglobin-standardization-program-2012-to-2015
#7
Kui Zhang, Yan Wang, Hongxia Wei, Zhiye Xu
PURPOSE: This study aims to investigate glycosylated hemoglobin (HbA1c), between-laboratory imprecision (%CV), and pass rates from 2012 to 2015 in Nanjing to provide evidence for improving the HbA1c measurement. METHODS: This was a retrospective, descriptive analysis of HbA1c levels obtained from participating hospitals in Nanjing from 2012 to 2015. The HbA1c levels of fresh whole blood samples taken from healthy and diabetic adults were determined within 24 hours...
December 2, 2016: Clinical Therapeutics
https://www.readbyqxmd.com/read/27919517/centrifugal-partition-chromatography-a-preparative-tool-for-isolation-and-purification-of-xylindein-from-chlorociboria-aeruginosa
#8
Anukul Boonloed, Genevieve L Weber, Kelly M Ramzy, Veronica R Dias, Vincent T Remcho
A centrifugal partition chromatography (CPC) method was developed for the preparative-scale isolation and purification of xylindein from the wood-staining fungi, Chlorociboria aeruginosa. Xylindein, a blue-green pigment naturally secreted from the hyphae and fruiting bodies of the fungus, has great value in the decorative wood industry and textile coloration. Xylindein has great potential for use as a fluorescent labeling agent as well as in organic semiconductor applications. However, a primary limitation of xylindein is its poor solubility in most common HPLC solvents...
November 18, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27918445/docetaxel-loaded-self-assembly-stearic-acid-modified-bletilla-striata-polysaccharide-micelles-and-their-anticancer-effect-preparation-characterization-cellular-uptake-and-in-vitro-evaluation
#9
Qingxiang Guan, Dandan Sun, Guangyuan Zhang, Cheng Sun, Miao Wang, Danyang Ji, Wei Yang
Poorly soluble drugs have low bioavailability after oral administration, thereby hindering effective drug delivery. A novel drug-delivery system of docetaxel (DTX)-based stearic acid (SA)-modified Bletilla striata polysaccharides (BSPs) copolymers was successfully developed. Particle size, zeta potential, encapsulation efficiency (EE), and loading capacity (LC) were determined. The DTX release percentage in vitro was determined using high performance liquid chromatography (HPLC). The hemolysis and in vitro anticancer activity were studied...
December 2, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/27917660/phytochemical-investigations-on-artemisia-alba-turra-growing-in-the-north-east-of-italy
#10
Gregorio Peron, Valeria Baldan, Stefania Sut, Marta Faggian, Lorenzo Roccabruna, Daniele Zanini, Paolo Manzini, Filippo Maggi, Stefano Dall'Acqua
Artemisia alba Turra (Asteraceae) is an Euro-Mediterranean plant used in Veneto (North-East of Italy) as traditional medicine for the treatment of various diseases. A. alba is a taxonomically problematic species, characterised by common polymorphism leading to a quite high variability in secondary metabolites content. Nonetheless, the phytochemical knowledge on its phytoconstituents, especially non-volatile components, is limited. In the present paper, the phytochemical composition of a tincture obtained from the aerial parts of A...
December 5, 2016: Natural Product Research
https://www.readbyqxmd.com/read/27917190/laser-microdissection-and-spatiotemporal-pinoresinol-lariciresinol-reductase-gene-expression-assign-the-cell-layer-specific-accumulation-of-secoisolariciresinol-diglucoside-in-flaxseed-coats
#11
Jingjing Fang, Aïna Ramsay, Sullivan Renouard, Christophe Hano, Frédéric Lamblin, Brigitte Chabbert, François Mesnard, Bernd Schneider
The concentration of secoisolariciresinol diglucoside (SDG) found in flaxseed (Linum usitatissimum L.) is higher than that found in any other plant. It exists in flaxseed coats as an SDG-3-hydroxy-3-methylglutaric acid oligomer complex. A laser microdissection method was applied to harvest material from different cell layers of seed coats of mature and developing flaxseed to detect the cell-layer specific localization of SDG in flaxseed; NMR and HPLC were used to identify and quantify SDG in dissected cell layers after alkaline hydrolysis...
2016: Frontiers in Plant Science
https://www.readbyqxmd.com/read/27916942/evidence-of-bioactive-compounds-from-vernonia-polyanthes-leaves-with-topical-anti-inflammatory-potential
#12
Kamilla C M Rodrigues, Lucas A Chibli, Bruna C S Santos, Vanessa S Temponi, Nícolas C C Pinto, Elita Scio, Glauciemar Del-Vechio-Vieira, Maria S Alves, Orlando V Sousa
Vernonia polyanthes Less. (Asteraceae), popularly known as "assa-peixe", is a plant species used in Brazilian traditional medicine for the treatment of cutaneous damage, cicatrization, inflammation, and rheumatism. Based on these ethnopharmacological findings, the current study evaluated the topical anti-inflammatory effects of the hexane (HEVP) and ethyl acetate (EAEVP) extracts from V. polyanthes leaves in experimental models of skin inflammation. Chemical characterization was carried out by HPLC-UV/DAD analysis...
December 1, 2016: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/27916854/fast-screening-of-antibacterial-compounds-from-fusaria
#13
Teis Esben Sondergaard, Marlene Fredborg, Ann-Maria Oppenhagen Christensen, Sofie K Damsgaard, Nikoline F Kramer, Henriette Giese, Jens Laurids Sørensen
Bio-guided screening is an important method to identify bioactive compounds from fungi. In this study we applied a fast digital time-lapse microscopic method for assessment of the antibacterial properties of secondary metabolites from the fungal genus Fusarium. Here antibacterial effects could be detected for antibiotic Y, aurofusarin, beauvericin, enniatins and fusaric acid after six hours of cultivation. The system was then used in a bio-guided screen of extracts from 14 different Fusarium species, which had been fractionated by HPLC...
November 29, 2016: Toxins
https://www.readbyqxmd.com/read/27916693/comparison-of-2-strategies-to-enhance-pyridoclax-solubility-nanoemulsion-delivery-system-versus-salt-synthesis
#14
A-C Groo, M De Pascale, A-S Voisin-Chiret, S Corvaisier, M Since, A Malzert-Fréon
Pyridoclax is an original oligopyridine lead, very promising in treatment of chemoresistant cancers. However, from solubility measurement and permeability evaluation, it appeared that this compound can be considered as a BCS II drug, with a poor water solubility. To overcome this unfavorable property, two strategies were proposed and compared: pyridoclax di-hydrochloride salt synthesis and formulation of pyridoclax-loaded nanoemulsions (PNEs) efficiently performed by transposing the spontaneous emulsification process previously developed by our team...
December 1, 2016: European Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/27916506/quantification-of-biologically-active-o-prenylated-and-unprenylated-phenylpropanoids-in-dill-anethum-graveolens-anise-pimpinella-anisum-and-wild-celery-angelica-archangelica
#15
Vito Alessandro Taddeo, Salvatore Genovese, Philippe de Medina, Roberta Palmisano, Francesco Epifano, Serena Fiorito
An analytical strategy based on different extraction methodologies and HPLC with spectrophotometric (UV-vis) detection has been developed to investigate the presence of and to quantitate biologically active selected unprenylated and O-prenylated phenylpropanoids, namely umbelliferone, 4'-geranyloxyferulic acid, 7-isopentenyloxycoumarin, auraptene, and umbelliprenin in dill (Anethum graveolens L.), anise (Pimpinella anisum L.), and wild celery (Angelica archangelica L.). Absolute ethanol or 7:3 water/ethanol mixtures were seen to be the most powerful extraction solvents to perform "classic" maceration or ultrasound-assisted one in terms of yields in secondary metabolites...
November 27, 2016: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/27916391/liquid-chromatography-electrospray-ionization-mass-spectrometry-for-the-simultaneous-quantitation-of-collagen-and-elastin-crosslinks
#16
Rafea Naffa, Geoff Holmes, Meekyung Ahn, David Harding, Gillian Norris
We have developed a novel chromatographic analytical method for the simultaneous quantitation of collagen crosslinks. Seven non-derivatised crosslinks could be separated on a Cogent Diamond Hydride HPLC column using either isocratic or gradient conditions then detected by mass spectrometry. The total run time was less than 10min which is significantly shorter than that previously reported. This is the first method in which histidinohydroxylysinonorleucine (HHL) and histidinohydroxymero-desmosine (HHMD) were separated and identified by mass spectrometry without the need for pre- or post-column derivatization...
November 29, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27916390/chromatographic-behavior-of-selected-antibiotic-drugs-supported-by-quantitative-structure-retention-relationships
#17
Malgorzata Szultka-Mlynska, Boguslaw Buszewski
As antibiotic drugs have a wide variety of applications, there is a growing demand for their selective determination, a task for which chromatographic methods seem to be appropriate. With this end in view, chromatographic measurements were performed with the use of six different HPLC columns (ACE 5C18, IAM.PC.DD.2, octadecyl, phenyl, alkylamide and cholesteryl-alkylamide) to determine the logkw of selected antibiotic drugs (amoxicillin, cefatoxime, ciprofloxacin, fluconazole, gentamicin, clindamycin, linezolid and metronidazole)...
November 29, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/27915331/screening-of-bioactive-ingredients-in-ligusticum-chuanxiong-hort-for-protection-against-myocardial-ischemia
#18
Xu Liu, Xiuzhong Li, Songgang Ji, Xiaobo Cui, Mingchun Li
BACKGROUND/AIMS: To study the spectrum-effect relationship and effective components of Ligusticum Chuanxiong Hort. (LCH) on the protection of canine myocardial ischemia. METHODS: Fingerprint spectrum of LCH extracts was developed using high performance liquid chromatography (HPLC), and a canine model of acute myocardial ischemia was established by ligating the coronary artery. Bivariate correlation analysis and multivariate regression analysis were used to correlate the pharmacodynamics of LCH extract and its common peaks in HPLC...
December 5, 2016: Cellular Physiology and Biochemistry
https://www.readbyqxmd.com/read/27915194/quantitative-determination-of-salbutamol-sulfate-impurities-using-achiral-supercritical-fluid-chromatography
#19
Amandine Dispas, Vincent Desfontaine, Bertyl Andri, Pierre Lebrun, Dorina Kotoni, Adrian Clarke, Davy Guillarme, Philippe Hubert
In the last years, supercritical fluid chromatography has largely been acknowledged as a singular and performing technique in the field of separation sciences. Recent studies highlighted the interest of SFC for the quality control of pharmaceuticals, especially in the case of the determination of the active pharmaceutical ingredient (API). Nevertheless, quality control requires also the determination of impurities. The objectives of the present work were to (i) demonstrate the interest of SFC as a reference technique for the determination of impurities in salbutamol sulfate API and (ii) to propose an alternative to a reference HPLC method from the European Pharmacopeia (EP) involving ion-pairing reagent...
November 27, 2016: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/27915192/the-profiling-of-the-metabolites-of-hirsutine-in-rat-by-ultra-high-performance-liquid-chromatography-coupled-with-linear-ion-trap-orbitrap-mass-spectrometry-an-improved-strategy-for-the-systematic-screening-and-identification-of-metabolites-in-multi-samples
#20
Jianwei Wang, Peng Qi, Jinjun Hou, Yao Shen, Min Yang, Qirui Bi, Yanping Deng, Xiaojian Shi, Ruihong Feng, Zijin Feng, Wanying Wu, Dean Guo
Drug metabolites identification and construction of metabolic profile are meaningful work for the drug discovery and development. The great challenge during this process is the work of the structural clarification of possible metabolites in the complicated biological matrix, which often resulting in a huge amount data sets, especially in multi-samples in vivo. Analyzing these complex data manually is time-consuming and laborious. The object of this study was to develop a practical strategy for screening and identifying of metabolites from multiple biological samples efficiently...
November 21, 2016: Journal of Pharmaceutical and Biomedical Analysis
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