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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 31 for “"Coumarins"”.
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Direct arylation of 2-pyrones, coumarins, 2-pyridinones and 2-quinolones
… successful intermolecular direct arylation of coumarins. This is followed by a discussion on the development of two sets of conditions enabling selective intramolecular double C-H activation of both the 2-pyrone and coumarin motif. The potential pathways and mechanisms for each of the …
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Design and applications of 4-yl-(methyl)coumarins and their derivatives
Surface chemistry is a well-established area of research and is required in many commercial applications. However, most surface modifications are static in nature meaning a single treatment will produce a single, fixed surface state (eg: hydrophobic, hydrophilic, etc.). Dynamic systems, those that …
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Investigação dos efeitos antibacteriano e citotóxico de cumarinas
… of this plant have shown the presence of coumarins as one of the most abundant chemical components which is probably responsible, together with other substances, the beneficial effect of infusions of shells. Coumarins are derived from the metabolism of phenylalanine, taking as initial …
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Synthesis of 4-Azidocoumarins and Their Use in Copper-Catalyzed Azide-Alkyne Cycloaddition reactions
… future medicines. In this work, various 4-azido-coumarins were synthesized via the transformation of the 4-hydroxy derivatives to 4-benzotriazolyloxy coumarins by reaction with the peptide coupling agent (benzotriazol-1-yloxy)tris-(dimethylamino)phosphonium hexafluorophosphate (BOP), and …
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The arylation of 2-pyrones and related heterocycles
… and related heterocycles such as 2-pyridones, 2-coumarins and 2- quinolones, are useful model substrates to test a novel methodology due to their varied chemical properties. In addition, these moieties possess broad spectrum biological activity. Chapter 1 provides a review of C–H activation …
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Synthesis Of 1,4-Triazolyl Combretacoumarins As Potential Anticancer Agents
<p>Coumarins are natural compounds that have various physiological and therapeutic properties, making them pharmacologically important. Combretastatin A-4 (CA-4) is a microtubule-binding agent that has potent cytotoxic effects against human cell lines. In CA-4 the trimethoxyarene moiety plays a …
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A fragment based approach to the development of novel antibacterial agents inspired by the natural product simocyclinone D8
… by exploring chlorination reactions of dihydroxycoumarins and their corresponding starting reagents. Additionally, there was a need to establish a viable route towards the complex polyketide scaffold. Secondly, to generate a library of coumarins and screen for a low molecular weight fragment that …
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Phytochemical screening and antibacterial testing of selected Namibian medicinal plants against laboratory and clinical bacteria that cause Diarrhoea
… triterpenoids, saponins, flavonoids, steroids, coumarins, tannins and alkaloids by thin layer chromatography (TLC). Antibacterial activities of the organic and aqueous extracts were determined against laboratory strains of Escherichia coli, Shigella bodyii, Staphylococcus aureus and Listeria …
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A Comparison of Theoretical and Actual Coumarin Exudation Under Iron Limitation to Understand Root Exudation Mechanics
… weight metabolites, including iron-fixing coumarins (scopoletin, fraxetin, etc.) are primarily exuded passively, and high molecular weight metabolites follow an active exudation approach. Scopoletin and scopolin exudation from Arabidopsis thaliana in low-iron and replete conditions is …
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ΣΥΜΒΟΛΗ ΣΤΗ ΜΕΛΕΤΗ ΤΩΝ ΧΗΜΙΚΩΝ ΣΥΣΤΑΤΙΚΩΝ ΤΩΝ ΑΝΘΕΩΝ ΤΟΥ FRAXINUS ORNUS
… AND GLYCOSYLATION ON THE U.V. SPECTRA OF OXYCOUMARINS HAVE BEEN NOTED. THE RESEARCH ON THE CONSTITUENTS OF THE FLOWERS HAVE BEEN PERFORMED IN TWOSTAGES. A. PRELIMINARY TESTS. THE FOLLOWING GROUPS OF SUBSTANCES HAVE BEEN DETECTED: TANNINS, AMINO ACIDS (8 IDENTIFIED) POLYPHENOLS (FLAVONOID, …
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Evaluation of indigenous Namibian mushrooms and plants for antimalarial properties
… profiles (saponins, terpenoids, anthraquinones, coumarins, alkaloids, and flavonoids) using standard procedures; elucidation of active antiplasmodial compounds using Gas chromatography-Mass Spectrometry (GC-MS), Fourier Transform Infrared (FTIR) and Nuclear Magnetic Resonance spectroscopy (NMR) …
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Chemo-morphological characterisation and some biological activities of pelargonium sidoides DC.
… the morphotypes were selected and screened for coumarins (umckalin, esculin and scopoletin) using Thin Layer Chromatography (TLC) and High Performance Liquid Chromatography (HPLC). Coumarins are known to exhibit moderate antibacterial and significant immunomodulatory capabilities. Variation was …
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Palladium and manganese catalysis in C-H activation
… involving the C-H activation of 2-pyrones and 2-coumarins. The cyclisation of 2-pyrones and 2-coumarins via double C-H activation is described in Chapter 2 of this thesis. The synthesis of a library of 2-pyrone and 2-coumarin substrates was achieved using this methodology. Excellent yields were …
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Action of Allelochemicals on Algal Growth and Photosystem Ii Efficiency
… for other sesquiterpene lactones, alkaloids, coumarins, flavonoids, and quinones ranged between 10 and 100 μM. The inhibition threshold was 100 μM or higher for benzoic and cinnamic acids. Sesquiterpene lactones were PSII inhibitors that had a positive correlation between growth suppression …
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Estudo ficoquímico e avaliação da atividade microbiológica de algas marinhas do gênero sargassum.
… which we can mention: alginates, florotaninos, coumarins, chromones, quinones, and terpenoids feoftinas . Studies have shown that metabolites produced by algae of the genus Sargass umtiveram biological activities, such as anticoagulant, antioxidant, analgesic and antipyretic . It is important to …
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Antibacterial, antioxidant and phytochemical investigation of Acacia Arenaria, Aloe Esculenta and Pechuel-Loeschea Leubnitziae
… saponins, flavonoids, anthraquinones, coumarins, alkaloids, phenols and tannins. The results obtained in the present study indicated that the leaves, stem and roots of A. esculenta, and A. arenaria, P. leubnitziae are potential sources of natural antioxidants and antimicrobials. Further …
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Phytochemical and Antimicrobial Studies on Selected Medicinal Plants from The Iraqi Flora: Citrus grandis, Citrus sinensis and Ruta chalepensis
… three compounds including two novel ones, mainly coumarins and flavonoids, were isolated from the active extracts/fractions using a combination of thin layer chromatography (TLC), solid-phase extraction and reversed-phase high-performance liquid chromatography (HPLC). 1D and 2D nuclear magnetic …
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Structure guided discovery of inhibitors of indoleamine 2,3-dioxygenase (IDO1)
… indoles, indan‐1‐ones, quinolines, naphthalenes, coumarins, biphenyls, phenols, 4‐phenylimidazole, pyridines, hydroxyamidines and phenylpyruvic acids. Spectroscopic studies show that these compounds interact with the haem complex present in the IDO1 active site. Of these, 4‐phenylimidazole and a …
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Phytochemical studies on natural products and their biological activities against Trypanosoma
… phenolic aldehydes, sesquiterpene quinines, coumarins, amino acids, steroids and inorganic compounds.;The present study employed high-resolution LC-MS, HPLC-ELSD and NMR profiling to analyse the chemical composition of Holy Basil (Ocimum sanctum L.) and a range of types of propolis from …
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An investigation into the antineoplastic properties of Schinziophyton Rautanenii and Colophospermum mopane
… in vivo in Planaria, for toxicity. Alkaloids, coumarins, flavonoids and triterpenes were found in all plant extracts, except anthraquinones which were only found in the root extract of S. rautanenii. Antioxidant activity shown by plant extracts was in correlation with the observed alkaloid …
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