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Biological Chemistry

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https://www.readbyqxmd.com/read/28644042/a-review-on-recent-applications-of-high-performance-liquid-chromatography-in-metal-determination-and-speciation-analysis
#1
Susheela Rani, Neha Sharma, Ashok Kumar Malik
High performance liquid chromatography has several advantages over the conventional methods due to their operational simplicity. It is a vital tool to determine metal ions having same mass but different electronic configuration, to separate complex mixtures and to resolve ions that may be indistinguishable by mass spectrometry alone. Metal ions play vital role in many biological processes and involved in setting up of many diseases. Therefore the development of simple methods for the detection and quantification of metals in real samples might serve as diagnostic tools for various diseases...
June 23, 2017: Critical Reviews in Analytical Chemistry
https://www.readbyqxmd.com/read/28644007/cyclotides-as-tools-in-chemical-biology
#2
Simon J de Veer, Joachim Weidmann, David J Craik
Among the various molecules that plants produce for defense against pests and pathogens, cyclotides stand out as exceptionally stable and structurally unique. These ribosomally synthesized peptides are around 30 amino acids in size, and are stabilized by a head-to-tail cyclic peptide backbone and three disulfide bonds that form a cystine knot. They occur in certain plants of the Rubiaceae, Violaceae, Cucurbitaceae, Fabaceae, and Solanaceae families, with an individual plant producing up to hundreds of different cyclotides...
June 23, 2017: Accounts of Chemical Research
https://www.readbyqxmd.com/read/28643351/quality-specifications-of-routine-clinical-chemistry-methods-based-on-sigma-metrics-in-performance-evaluation
#3
Jun Xia, Su-Feng Chen, Fei Xu, Yong-Lie Zhou
INTRODUCTION: Sigma metrics were applied to evaluate the performance of 20 routine chemistry assays, and individual quality control criteria were established based on the sigma values of different assays. METHODS: Precisions were expressed as the average coefficient variations (CVs) of long-term two-level chemistry controls. The biases of the 20 assays were obtained from the results of trueness programs organized by National Center for Clinical Laboratories (NCCL, China) in 2016...
June 23, 2017: Journal of Clinical Laboratory Analysis
https://www.readbyqxmd.com/read/28642381/chemical-transformation-of-xenobiotics-by-the-human-gut-microbiota
#4
REVIEW
Nitzan Koppel, Vayu Maini Rekdal, Emily P Balskus
The human gut microbiota makes key contributions to the metabolism of ingested compounds (xenobiotics), transforming hundreds of dietary components, industrial chemicals, and pharmaceuticals into metabolites with altered activities, toxicities, and lifetimes within the body. The chemistry of gut microbial xenobiotic metabolism is often distinct from that of host enzymes. Despite their important consequences for human biology, the gut microbes, genes, and enzymes involved in xenobiotic metabolism are poorly understood...
June 23, 2017: Science
https://www.readbyqxmd.com/read/28641555/supervised-machine-learning-methods-applied-to-predict-ligand-binding-affinity
#5
Gabriela Sehnem Heck, Val Oliveira Pintro, Richard Rene Pereira, Mauricio Boff de Ávila, Nayara Maria Bernhardt Levin, Walter Filgueira de Azevedo
BACKGROUND: Calculation of ligand-binding affinity is an open problem in computational medicinal chemistry. The ability to computationally predict affinities has a beneficial impact in the early stages of drug development, since it allows a mathematical model to assess protein-ligand interactions. Due to the availability of structural and binding information, machine learning methods have been applied to generate scoring functions with good predictive power. OBJECTIVE: Our goal here is to review recent developments in the application of machine learning methods to predict ligand- binding affinity...
June 22, 2017: Current Medicinal Chemistry
https://www.readbyqxmd.com/read/28640998/oximes-and-hydrazones-in-bioconjugation-mechanism-and-catalysis
#6
Dominik K Kölmel, Eric T Kool
The formation of oximes and hydrazones is employed in numerous scientific fields as a simple and versatile conjugation strategy. This imine-forming reaction is applied in fields as diverse as polymer chemistry, biomaterials and hydrogels, dynamic combinatorial chemistry, organic synthesis, and chemical biology. Here we outline chemical developments in this field, with special focus on the past ∼10 years of developments. Recent strategies for installing reactive carbonyl groups and α-nucleophiles into biomolecules are described...
June 22, 2017: Chemical Reviews
https://www.readbyqxmd.com/read/28640526/development-and-characterisation-of-a-99m-tc-tricarbonyl-labelled-estradiol-derivative-obtained-by-click-chemistry-with-potential-application-in-estrogen-receptors-imaging
#7
María Emilia Tejería, Javier Giglio, Silvia Dematteis, Ana Rey
Assessment of the presence of estrogen receptors in breast cancer is crucial for treatment planning. With the objective to develop a potential agent for estrogen receptors imaging we present the development and characterization of a (99m) Tc tricarbonyl labelled estradiol derivative. Using ethinylestradiol as starting material, a estradiol derivative bearing a 1,4-disubstituted 1,2,3-triazole-containing tridentate ligand system was synthesized by "Click Chemistry" and fully characterized. Labelling with high yield and radiochemical purity was achieved through the formation of a (99m) Tc-tricarbonyl complex...
June 22, 2017: Journal of Labelled Compounds & Radiopharmaceuticals
https://www.readbyqxmd.com/read/28639657/exploring-the-catalytic-mechanism-of-dihydropteroate-synthase-elucidating-the-differences-between-the-substrate-and-inhibitor
#8
Warot Chotpatiwetchkul, Kanokthip Boonyarattanakalin, Duangkamol Gleeson, M Paul Gleeson
Dihydropteroate synthase (DHPS) catalyzes the condensation of 6-hydroxymethyl-7,8-dihydropterin pyrophosphate (DHPPP) with p-aminobenzoic acid (pABA) and is a well validated target for anti-malarial and anti-bacterial drugs. However, in recent years its utility as a therapeutic target has diminished considerably due to multiple mutations. As such, considerable structural biology and medicinal chemistry effort has been expended to understand and overcome this issue. To date no detailed computational analysis of the protein mechanism has been made despite the detailed crystal structures and multiple mechanistic proposals being made...
June 22, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28639641/incorporation-of-click-chemistry-glycomimetics-dramatically-alters-triple-helix-stability-in-an-adiponectin-model-peptide
#9
Katherine R Lutteroth, Paul W R Harris, Tom H Wright, Harveen Kaur, Kevin Sparrow, Sung-Hyun Yang, Garth J S Cooper, Margaret A Brimble
Adiponectin (Adpn) has been shown to be a possible therapeutic for Type II diabetes, however the production of a therapeutic version of Adpn has proved to be challenging. Biological studies have highlighted the importance of the glycosylated lysine residues for the formation of bioactive high molecular weight oligomers of Adpn. Through the use of 'click' glycopeptide mimetics, we investigated the role of glycosylated lysine and serine residues for the formation of triple helical structures of the collagenous domain of Adpn, in the context of a collagen model peptide scaffold...
June 22, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28638777/heterobifunctional-dyes-highly-fluorescent-linkers-based-on-cyanine-dyes
#10
Virginia Wycisk, Katharina Achazi, Ole Hirsch, Christian Kuehne, Jens Dernedde, Rainer Haag, Kai Licha
Herein, we present a new synthetic route to cyanine-based heterobifunctional dyes and their application as fluorescent linkers between polymers and biomolecules. The synthesized compounds, designed in the visible spectral range, are equipped with two different reactive groups for highly selective conjugation under physiological conditions. By applying indolenine precursors with functionalized benzenes, we achieved water-soluble asymmetric cyanine dyes bearing maleimido and N-hydroxysuccinimidyl functionalities in a three-step synthesis...
June 2017: ChemistryOpen
https://www.readbyqxmd.com/read/28638769/deeper-insight-into-the-six-step-domino-reaction-of-aldehydes-with-malononitrile-and-evaluation-of-antiviral-and-antimalarial-activities-of-the-obtained-bicyclic-products
#11
Christina M Bock, Gangajji Parameshwarappa, Simon Bönisch, Walter Bauer, Corina Hutterer, Maria Leidenberger, Oliver Friedrich, Manfred Marschall, Barbara Kappes, Andreas Görling, Svetlana B Tsogoeva
The straightforward and efficient synthesis of complex aza- and carbobicyclic compounds, which are of importance for medicinal chemistry, is a challenge for modern chemical methodology. An unprecedented metal-free six-step domino reaction of aldehydes with malononitrile was presented in our previous study to provide, in a single operation, these bicyclic nitrogen-containing molecules. Presented here is a deeper investigation of this atom-economical domino process by extending the scope of aldehydes, performing post-modifications of domino products, applying bifunctional organocatalysts and comprehensive NMR studies of selected domino products...
June 2017: ChemistryOpen
https://www.readbyqxmd.com/read/28637365/insight-into-the-c-f-bond-mechanism-of-molecular-analogs-for-antibacterial-drug-design
#12
Junna Liu, Biyu Lv, Huaqing Liu, Xin Li, Weiping Yin
The activities of biological molecules usually rely on both of intra-molecular and intermolecular interactions between their function groups. These interactions include interonic attraction theory, Van der Waal's forces and the function of geometry on the individual molecules, whether they are naturally or synthetic. The purpose of this study was to evaluate the antibacterial activity of C-F bond compound using combination of experiments verification and theoretical calculation. We target on the insect natural products from the maggots of Chrysomyis megacephala Fabricius...
June 21, 2017: Natural Product Research
https://www.readbyqxmd.com/read/28637351/tuning-surface-chemistry-of-polyetheretherketone-by-gold-coating-and-plasma-treatment
#13
Zdeňka Novotná, Silvie Rimpelová, Petr Juřík, Martin Veselý, Zdeňka Kolská, Tomáš Hubáček, Jakub Borovec, Václav Švorčík
Polyetheretherketone (PEEK) has good chemical and biomechanical properties that are excellent for biomedical applications. However, PEEK exhibits hydrophobic and other surface characteristics which cause limited cell adhesion. We have investigated the potential of Ar plasma treatment for the formation of a nanostructured PEEK surface in order to enhance cell adhesion. The specific aim of this study was to reveal the effect of the interface of plasma-treated and gold-coated PEEK matrices on adhesion and spreading of mouse embryonic fibroblasts...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28636761/molecular-tools-for-facilitative-carbohydrate-transporters
#14
Marina Tanasova, Joseph R Fedie
Facilitative carbohydrate transporters - Gluts - have received a wide attention over decades due to their essential role in the nutrient uptake and links with various metabolic disorders, including diabetes, obesity, and cancer. Endeavors into understanding mechanisms of Glut-mediated nutrient uptake have resulted in the multidisciplinary research field, branching protein chemistry, chemical biology, organic synthesis, crystallography, and biomolecular modeling. Gluts became attractive targets for cancer research and medicinal chemistry, leading to the development of new approaches to cancer diagnostics and providing avenues for cancer-targeting therapeutics...
June 21, 2017: Chembiochem: a European Journal of Chemical Biology
https://www.readbyqxmd.com/read/28636366/oxygenation-via-c-h-c-c-bond-activation-with-molecular-oxygen
#15
Yu-Feng Liang, Ning Jiao
The selective oxidation of organic molecules is a fundamentally important component of modern synthetic chemistry. In the past decades, direct oxidative C-H and C-C bond functionalization has proved to be one of the most efficient and straightforward methods to synthesize complex products from simple and readily available starting materials. Among these oxidative processes, the use of molecular oxygen as a green and sustainable oxidant has attracted considerable attention because of its highly atom-economical, abundant, and environmentally friendly characteristics...
June 21, 2017: Accounts of Chemical Research
https://www.readbyqxmd.com/read/28636358/transferable-atom-centered-potentials-for-the-correction-of-basis-set-incompleteness-errors-in-density-functional-theory
#16
Alberto Otero-de-la-Roza, Gino A DiLabio
Recent progress in the accurate calculation of non-covalent interactions has enabled density-functional theory (DFT) to model systems relevant in biological and supramolecular chemistry. The application of DFT methods using atom-centered Gaussian basis sets to large systems is limited by the number of basis functions required to accurately model thermochemistry and, in particular, weak intermolecular interactions. Basis-set incompleteness error (BSIE) arising from the use of incomplete basis sets leads to erroneous intermolecular energies, bond dissociation energies, and structures...
June 21, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28636349/water-dynamics-from-the-surface-to-the-interior-of-a-supramolecular-nanostructure
#17
Julia H Ortony, Baofu Qiao, Christina J Newcomb, Timothy J Keller, Liam C Palmer, Elad Deiss-Yehiely, Monica Olvera de la Cruz, Songi Han, Samuel I Stupp
Water within and surrounding the structure of a biological system adopts context-specific dynamics that mediate virtually all of the events involved in the inner workings of a cell. These events range from protein folding and molecular recognition to the formation of hierarchical structures. Water dynamics are mediated by the chemistry and geometry of interfaces where water and biomolecules meet. Here we investigate experimentally and computationally the translational dynamics of vicinal water molecules within the volume of a supramolecular peptide nanofiber measuring 6...
June 21, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28636311/insights-into-integrated-lead-generation-and-target-identification-in-malaria-and-tuberculosis-drug-discovery
#18
John Okombo, Kelly Chibale
New, safe and effective drugs are urgently needed to treat and control malaria and tuberculosis, which affect millions of people annually. However, financial return on investment in the poor settings where these diseases are mostly prevalent is very minimal to support market-driven drug discovery and development. Moreover, the imminent loss of therapeutic lifespan of existing therapies due to evolution and spread of drug resistance further compounds the urgency to identify novel effective drugs. However, the advent of new public-private partnerships focused on tropical diseases and the recent release of large data sets by pharmaceutical companies on antimalarial and antituberculosis compounds derived from phenotypic whole cell high throughput screening have spurred renewed interest and opened new frontiers in malaria and tuberculosis drug discovery...
June 21, 2017: Accounts of Chemical Research
https://www.readbyqxmd.com/read/28635265/metabolic-oligosaccharide-engineering-with-alkyne-sialic-acids-confers-neuraminidase-resistance-and-inhibits-influenza-reproduction
#19
Torben Heise, Christian Büll, Daniëlle M H Beurskens, Emiel Rossing, Marien de Jonge, Gosse J Adema, Thomas J Boltje, Jeroen Langereis
Metabolic incorporation of azide or alkyne modified sialic acids into the cellular glycosylation pathway enables the study of sialoglycan expression, localization and trafficking via bioorthogonal chemistry. Herein we report that such modifications of the sialic acid sugar can have a profound influence on their hydrolysis by neuraminidases (sialidase). Azidoacetyl modified sialic acids were prone to neuraminidase cleavage, whereas propargyloxycarbonyl (Poc) modified sialic acids were largely resistent to cleavage...
June 21, 2017: Bioconjugate Chemistry
https://www.readbyqxmd.com/read/28632928/n-acylsulfonamides-synthetic-routes-and-biological-potential-in-medicinal-chemistry
#20
REVIEW
Alessandra Ammazzalorso, Barbara De Filippis, Letizia Giampietro, Rosa Amoroso
Sulfonamide is a common structural motif in naturally occurring and synthetic medicinal compounds. The rising interest in sulfonamides and N-acyl derivatives is attested by the large number of drugs and lead compounds identified in last years, explored in different fields of medicinal chemistry and showing biological activity. Many acylsulfonamide derivatives were designed and synthesized as isosteres of carboxylic acids, being the characteristics of these functional groups very close. Starting from chemical routes to N-acylsulfonamides, this review explores compounds of pharmaceutical interest, developed as enzymatic inhibitors or targeting receptors...
June 20, 2017: Chemical Biology & Drug Design
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