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https://www.readbyqxmd.com/read/28545167/synthesis-of-s-2-s-3-4-chlorophenyl-n-4-chlorophenyl-sulfonyl-4-phenyl-4-5-dihydro-1h-pyrazole-1-carboximidamido-3-methyl-d3-butanamide-d5-octa-deuterated-jd5037
#1
Malliga R Iyer, Resat Cinar, Nathan J Coffey, Robert J Chorvat, George Kunos
JD5037 (1) is a potent and selective, peripherally acting inverse agonist of the cannabinoid (CB1 R) receptor. Peripheral CB1 receptor antagonists/inverse agonists have great potential in the treatment of metabolic disorders like type 2 diabetes, obesity and NASH. We report the synthesis of octa-deuterated [(2) H8 ]-JD5037 (S, S) (8) along with its (S, R) diastereomer (13) from commercially available L-valine-d8 starting material. The [(2) H8 ]-JD5037 compound will be used to quantitate unlabeled JD5037 during clinical ADME studies and will be used as an LC-MS/MS bioanalytical standard...
May 25, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
https://www.readbyqxmd.com/read/28544884/a-validated-uhplc-qtof-ms-method-for-quantification-of-metformin-and-teneligliptin-in-rat-plasma-application-to-pharmacokinetic-interaction-study
#2
David Paul, Lingesh Allakonda, Nanjappan Satheeshkumar
In this study a sensitive UHPLC-QTOF-MS method was developed and validated for the quantitation of the metformin (MET) and teneligliptin (TEN) in rat plasma using dapagliflozin as an internal standard (IS). Chromatographic separation were carried out on a Acquity UPLC HSS Cyano column (100mm x 2.1mm, 1.8μm) using gradient mobile phase system consisting of 0.1% formic acid and acetonitrile at a flow rate of 0.4mL/min, within a run time of 6min. Protein precipitation method was used as sample preparation approach...
May 15, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28544266/pcr-incorporation-of-polyoxometalate-modified-deoxynucleotide-triphosphates-and-their-application-in-molecular-electrochemical-sensing-of-yersinia-pestis
#3
Ciara K O'Sullivan, Mayreli Ortiz, Ahmed Debela Mehdi, Marketa Svobodova, Serge Thorimbert, Denis Lasage, Richard Cole, Bernold Hasenknopf
Redox-labeled nucleotides are of increasing interest for the fabrication of next generation molecular tools and should meet requirements of being thermally stable, sensitive, and compatible with polymerase-mediated incorporation whilst also being electrochemically discriminable. The synthesis and characterization of Keggin and Dawson polyoxometalate-deoxynucleotide (POM-dNTP) bioconjugates linked through 7-deaza-modified purines is described. The modified POM-dNTPs were used for polymerase based amplification of a DNA sequence specific for Yersinia pestis and the amplified DNA detected via an electrochemical DNA sensor...
May 22, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28541189/deep-reaching-hydrodynamic-flow-confinement-micrometer-scale-liquid-localization-for-open-substrates-with-topographical-variations
#4
Ali Oskooei, Govind V Kaigala
We present a method for nonintrusive localization and reagent delivery on immersed biological samples with topographical variation on the order of hundreds of micrometers. Our technique, which we refer to as the deep-reaching hydrodynamic flow confinement (DR-HFC), is simple and passive: it relies on a deep-reaching hydrodynamic confinement delivered through a simple microfluidic probe design to perform localized microscale alterations on substrates as deep as 600 μm. Designed to scan centimeter-scale areas of biological substrates, our method passively prevents sample intrusion by maintaining a large gap between the probe and the substrate...
June 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28538205/a-rapid-microextraction-by-packed-sorbent-liquid-chromatography-tandem-mass-spectrometry-method-for-the-determination-of-dexamethasone-disodium-phosphate-and-dexamethasone-in-aqueous-humor-of-patients-with-uveitis
#5
Federica Bianchi, Monica Mattarozzi, Nicolò Riboni, Paolo Mora, Stefano A Gandolfi, Maria Careri
A new method based on microextraction by packed sorbent (MEPS) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed and validated for the determination of dexamethasone and dexamethasone disodium phosphate in human aqueous humor. A central composite design was applied to investigate the effects of both loading and eluting cycles in the MEPS procedure; subsequently the multicriteria method of the desirability functions allowed to find the best conditions for the simultaneous extraction of both the analytes...
May 15, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28536716/on-chip-hydrodynamic-chromatography-of-dna-through-centimeters-long-glass-nanocapillaries
#6
Lian Duan, Levent Yobas
This study demonstrates hydrodynamic chromatography of DNA fragments in a microchip. The microchip contains a highly regular array of nanofluidic channels (nanocapillaries) that are essential for resolving DNA in this chromatography mode. The nanocapillaries are self-enclosed robust structures built inside a doped glass layer on silicon using low-resolution photolithography and standard semiconductor processing techniques. Additionally, the unique nanocapillaries feature a cylindrical inner radius of 600 nm maintained over a length scale of 5 cm...
May 24, 2017: Analyst
https://www.readbyqxmd.com/read/28534415/sequence-and-structure-dual-dependent-interaction-between-small-molecules-and-dna-for-the-detection-of-residual-silver-ions-in-as-prepared-silver-nanomaterials
#7
Zhaoyin Wang, Jian Zhao, Zijun Li, Jianchun Bao, Zhihui Dai
Investigations on interaction between small molecules and DNA are the basis of designing advanced bioanalytical systems. We herein propose a novel interaction between heterocyclic aromatic compounds (HACs) and single-stranded DNA (ssDNA). Taking methylene blue (MB) as a typical HAC, it is found that MB can interact with cytosine (C)-rich ssDNA in an enthalpy-driven process. The interaction between MB and C-rich ssDNA is sequence and structure dual-dependent: at least three consecutive C and single-stranded structure are necessary...
May 23, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28531124/the-occurrence-and-diversity-of-waterborne-fungi-in-african-aquatic-systems-their-impact-on-water-quality-and-human-health
#8
REVIEW
Nontokozo M Magwaza, Edward N Nxumalo, Bhekie B Mamba, Titus A M Msagati
Currently, there is a worldwide growing interest in the occurrence and diversity of fungi and their secondary metabolites in aquatic systems, especially concerning their role in water quality and human health. However, this concern is hampered by the scant information that is available in the literature about aquatic fungi and how they affect water quality. There are only few published reports that link certain species of aquatic fungi to human health. The common aquatic fungal species that have been reported so far in African aquatic systems belong to the hyphomycetes kingdom...
May 20, 2017: International Journal of Environmental Research and Public Health
https://www.readbyqxmd.com/read/28524734/capillary-microsampling-in-nonclinical-safety-assessment-practical-sampling-and-bioanalysis-from-a-cro-perspective
#9
David Coleman, Graeme Smith, Rachel Lawrence, Deborah McManus, Sunetha Diaram, Joanna Edwards
Microsampling has the 3R benefits of refining blood collection techniques while reducing the number of animals required for rodent safety assessment studies. There are significant scientific benefits of correlating study findings with systemic exposure and consequently, there is an industry drive to utilize microsampling in regulatory toxicology studies. This article will focus on capillary microsampling and will discuss the initial considerations before using capillary microsampling, study design and some practicalities of sample collection...
May 19, 2017: Bioanalysis
https://www.readbyqxmd.com/read/28521623/enzyme-linked-immunoassay-based-quantitative-measurement-of-apolipoprotein-b-apob-in-dried-blood-spots-a-biomarker-of-cardiovascular-disease-risk
#10
Geeta N Eick, Paul Kowal, Tyler Barrett, Elizabeth A Thiele, J Josh Snodgrass
Apolipoprotein B (ApoB) is a strong predictor of cardiovascular disease, which remains the leading cause of mortality in both higher and lower income countries. Here, we adapted an enzyme-linked immunosorbent assay (ELISA) development kit for quantitative determination of ApoB levels in serum and plasma for use with dried blood spots (DBS). After confirming the dilution linearity of the assay for DBS, we measured ApoB in 208 venous DBS samples. Then, using Passing-Bablok regression analysis and Spearman rank correlation analysis, we evaluated the correspondence in ApoB values between matched plasma and finger-prick DBS samples from 40 individuals who had ApoB values spanning the range of ApoB values observed in the 208 vDBS samples...
2017: Biodemography and Social Biology
https://www.readbyqxmd.com/read/28521276/an-atmospheric-pressure-ionization-source-using-a-high-voltage-target-compared-to-electrospray-ionization-for-the-lc-ms-analysis-of-pharmaceutical-compounds
#11
Arnaud Lubin, Ronald De Vries, Deirdre Cabooter, Patrick Augustijns, Filip Cuyckens
The type and design of an ionization source can have a significant influence on the performances of a bioanalytical method. It is, therefore, of high interest to evaluate the performances of newly introduced sources to highlight their benefits and limitations in comparison to other well established sources. In this paper, liquid chromatography - mass spectrometry (LC/MS) performances of a new atmospheric pressure ionization (API) source, commercialized as UniSpray, is evaluated. The dynamic range of 24 pharmaceutical and biological compounds is compared between the new API source and electrospray ionization (ESI) for 3 different mobile phase conditions...
May 4, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28520459/feedback-from-the-ebf-focus-workshop-bringing-assay-validation-and-analysis-of-biomarkers-into-practice
#12
Philip Timmerman, Marianne Scheel Fjording, John Allinson, Cecilia Arfvidsson, Begoña Barroso, Ulf Diczfalusy, Adrian Freeman, Elizabeth Hickford, Hamza Kandousi, Sidath Katugampola, Ulrich Kunz, Robert Nelson, John Smeraglia
European Bioanalysis Forum, Lisbon, Portugal, 9-10 June 2016 At the recent European Bioanalysis Forum's Focus Workshop 'Bringing Assay Validation and Analysis of Biomarkers into Practice', the discussion on best practice for biomarker assay validation continued. Both the presentations and the adjacent panel discussions yielded valuable food for thought for the broader bioanalytical community. The present conference report summarizes the essence from these discussions and from the proposals or conclusions made by all delegates on how to increase the necessary connectivity of the stakeholders involved in the bioanalysis of biomarkers...
May 18, 2017: Bioanalysis
https://www.readbyqxmd.com/read/28518128/an-in-vitro-caseum-binding-assay-that-predicts-drug-penetration-in-tuberculosis-lesions
#13
Jansy P Sarathy, Hsin-Pin Ho Liang, Danielle Weiner, Jacqueline Gonzales, Laura E Via, Véronique Dartois
The eradication of tuberculosis disease requires drug regimens that can penetrate the multiple layers of complex pulmonary lesions. Drug distribution in the caseous cores of cavities and lesions is especially crucial because they harbor subpopulations of drug-tolerant bacteria also commonly referred to as persisters. Existing methods for the measurement of drug penetration in tuberculosis lesions involve costly and time-consuming in vivo pharmacokinetic studies coupled to bioanalytical or imaging techniques...
May 8, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28513744/high-affinity-recognition-of-the-human-c-reactive-protein-independent-of-phosphocholine
#14
Jie Yang, Anna-Lena Gustavsson, Martin Haraldsson, Göran Karlsson, Thomas Norberg, Lars Baltzer
A high-affinity polypeptide conjugate 4-C25L22-DQ, has been developed for the molecular recognition of the human C-reactive protein, CRP, a well-known inflammation biomarker. CRP is one of the most frequently quantified targets in diagnostic applications and a target in drug development. With the exception of antibodies, most molecular constructs take advantage of the known affinity for CRP of phosphocholine that depends on Ca(2+) for its ability to bind. 4-C25L22-DQ which is unrelated to phosphocholine binds in the absence of Ca(2+) with a dissociation constant of 760 nM, an order of magnitude lower than that of phosphocholine, the KD of which is 5 μM...
May 17, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28511118/simultaneous-determination-of-selective-serotonin-reuptake-inhibitors-and-their-main-metabolites-in-human-breast-milk-by-liquid-chromatography-electrospray-mass-spectrometry
#15
Etienne Weisskopf, Alice Panchaud, Kim An Nguyen, Delphine Grosjean, Jean-Michel Hascoët, Chantal Csajka, Chin B Eap, Nicolas Ansermot
A bioanalytical method by high performance liquid chromatography coupled to electrospray mass spectrometry (HPLC-ESI-MS), adapted from a previously published method in plasma, was validated in breast milk for the simultaneous quantification of all antidepressants belonging to the class of selective serotonin reuptake inhibitors (citalopram, fluoxetine, fluvoxamine, paroxetine and sertraline) and their major metabolites (desmethylcitalopram and norfluoxetine). Milk samples (250μl) first underwent protein precipitation followed by solid-phase extraction on a reversed phase/cation exchange sorbent...
July 1, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28504570/saliva-a-reliable-sample-matrix-in-bioanalytics
#16
Michael Gröschl
Saliva is gaining increasing attention as a bioanalytical sample matrix. Mostly because of the easy and noninvasive collection, it is not only beneficial in endocrinological and behavioral science, but also in pediatrics. Saliva also has the advantage of being the only body fluid which can be collected even during physical exercise, for example, during sportive activities, and there are physiological characteristics that make it superior to serum/plasma or urine for specific scientific questions. This review provides an insight into the physiology of saliva formation, explaining how certain compounds enter this bodily fluid, and gives advice for collection, storage and analytical methods...
May 15, 2017: Bioanalysis
https://www.readbyqxmd.com/read/28504549/determination-of-naloxegol-in-human-biological-matrices
#17
Yan Li, Mark Hoffmann, Paul Severin
AIM: Naloxegol is an oral peripherally acting μ-opioid receptor antagonist approved for the treatment of opioid-induced constipation. Sensitive, robust, bioanalytical methods were required to quantitate naloxegol in human biological matrices as part of the clinical development program. Results/methodology: Analytical plasma samples were prepared using Solid Phase Extraction (SPE) coupled with concentration. The method's linearity was established at 0.1-50 ng/ml with up to 100-fold dilution...
May 15, 2017: Bioanalysis
https://www.readbyqxmd.com/read/28499151/biphenyl-based-stationary-phases-for-improved-selectivity-in-complex-steroid-assays
#18
Johanna M Lindner, Michael Vogeser, Stefanie H Grimm
The measurement of steroid hormones and their corticoid precursors is an important aspect in endocrinology since these analytes are biomarkers for several endocrine disorders. Over the last few years, HPLC-MS/MS has become the method of choice to analyze these compounds. There are already several methods using stationary phases modified with C18 groups. However, since these columns sometimes do not enable sufficient separation of some isobaric steroids, we investigated the potential of a different RP modification using biphenyl groups for the separation of challenging isobars such as corticosterone, 11- and 21-deoxycortisol...
April 19, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28496063/fabrication-of-water-soluble-fluorescent-polymeric-micelles-for-selective-detection-of-hg-2-in-blood-serum
#19
Hong Wang, Jian Chen, Yongxiang Hong, Kun Lv, Maolin Yu, Peisheng Zhang, Yunfei Long, Pinggui Yi
In this study, amphiphilic diblock copolymers were designed and synthesized via the incorporation of reversible addition-fragmentation chain transfer radical polymerization (RAFT) and a subsequent grafting technique. Subsequently, Hg(2+)-sensitive water-soluble fluorescent polymeric micelles (FNs) were prepared by a reprecipitation strategy. The spectroscopic characteristics demonstrate that the fluorescein isothiocyanate (FITC) was successfully linked into the polymer. Due to the promoted reaction of desulfurization cyclization by Hg(2+), the fluorescence of fluorescein in FNs was obviously quenched...
2017: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
https://www.readbyqxmd.com/read/28494515/potent-and-selective-inhibitors-of-11%C3%AE-hydroxysteroid-dehydrogenase-type-1-labeled-with-carbon-13-and-carbon-14
#20
Bachir Latli, Matt Hrapchak, Jolaine Savoie, Yongda Zhan, Carl A Busacca, Chris H Senanayake
(S)-6-(2-Hydroxy-2-methylpropyl)-3-((S)-1-(4-(1-methyl-2-oxo-1,2-dihydropyridin-4-yl)phenyl)ethyl)-6-phenyl-1,3-oxazinan-2-one (1) and (4aR,9aS)-1-(1H-benzo[d]midazole-5-carbonyl)-2,3,4,4a,9,9a-hexahydro-1-H-indeno[2,1-b]pyridine-6-carbonitrile hydrochloride (2) are potent and selective inhibitor of 11β-hydroxysteroid dehydrogenase type 1 enzyme. These two drug candidates developed for the treatment of type-2 diabetes were prepared labeled with carbon-13 and carbon-14 to enable drug metabolism, pharmacokinetics, bioanalytical, and other studies...
May 11, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
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