Global ETD Search

21	Quantenchemische Berechnung von Übergangsmetallkomplexen in der Gasphase Diefenbach, Martin Ansgar. Unknown Date (has links) (PDF) Techn. Universiẗat, Diss., 2003--Berlin.
22	Aromatische Sulfonate Untersuchungen zum Stoffverhalten in Industrieabwasser und aquatischer Umwelt mit HPLC-MS / Storm, Thomas. Unknown Date (has links) (PDF) Techn. Universiẗat, Diss., 2002--Berlin.
23	Enhancing hypothiocyanite production by lactoperoxidase – mechanism and chemical properties of promotors Gau, Jana, Furtmüller, Paul-Georg, Obinger, Christian, Arnhold, Jürgen, Flemmig, Jörg 30 June 2016 (has links) (PDF) Background: The heme enzyme lactoperoxidase is found in body secretions where it significantly contributes to the humoral immune response against pathogens. After activation the peroxidase oxidizes thiocyanate to hypothiocyanite which is known for its microbicidal properties. Yet several pathologies are accompanied by a disturbed hypothiocyanite production which results in a reduced immune defense. Methods: The results were obtained by measuring enzyme-kinetic parameters using UV–vis spectroscopy and a standardized enzyme-kinetic test system as well as by the determination of second order rate constants using stopped-flow spectroscopy. Results: In this study we systematically tested thirty aromatic substrates for their efficiency to promote the lactoperoxidase-mediated hypothiocyanite production by restoring the native ferric enzyme state. Thereby hydrophobic compounds with a 3,4-dihydroxyphenyl partial structure such ashydroxytyrosol and selected flavonoids emerged as highly efficient promotors of the (pseudo-)halogenating lactoperoxidase activity. Conclusions: This study discusses important structure-function relationships of efficient aromatic LPO substrates and may contribute to the development of new agents to promote lactoperoxidase activity in secretory fluids of patients. Significance: This study may contribute to a better understanding of the (patho-)physiological importance of the (pseudo-)halogenating lactoperoxidase activity. The presented results may in future lead to the development of new therapeutic strategies which, by reactivating lactoperoxidase-derived hypothiocyanite production, promote the immunological activity of this enzyme. 3 4-dihydroxylierte Verbindungen aromatische Verbindungen Hypothiocyanit Entzündung Lactoperoxidase (LPO) Peroxidasen 3 4-dihydroxylatedcompounds aromatic compounds hypothiocyanite inflammation lactoperoxidase peroxidases ddc:540 ddc:610
24	Functional Aromatic Amino Ketones as UV/Vis probes for various liquid and solid environments El-Sayed, Mohamed 01 April 2003 (has links) Zum gegenwärtigen Kenntnisstand bezüglich Solvatochromie, Sol-Gel Prozesse, und der Synthese von Polyketonen wird eine kurze Einführung gegeben. Die Synthesekonzeptionen funktionalisierter aromatischer Aminoketone wereden vorgestellt. Die neun Verbindungen wurden mittels Elementaranalyse, Röntgenstrukturanalyse, und spektroskopischen (NMR, UV/Vis, MS) Methoden aufgeklärt. Im Mittelpunkt der Untersuchungen steht die Untersuchung des Einflusses von unterschiedlichen Medien (Lösungmittel, Oberflächen, Sol-Gel Materialien und Nachbarnmoleküle im Kristall) auf die Lage der UV/Vis-Absorptionsmaxima verschiedener aromatischer Aminoketone. Die Ergebnisse der Untersuchungen liefern Informationen in Bezug auf das spezifische Solvatationsvermögen, die Polarität von Feststoffoberflächen, der Einfluss funktionaler Gruppen in aromatischen Aminoketonen auf die intermolekulare Wasserstoffbrückenbindungen in Kristallen, und über die Natur der Gast-Host-Wechselwirkungen. Auf der Basis von nucleophilen Substitutionsreaktionen wurden zwei verschiedene Prozesse für die Synthese von Ploy(benzophenone-co-piperazin) und der Kompositform entwickelt. Molekulare Strukturen und Eigenschaften konnten durch Elementaranalyse, mehrere spektroskopische (IR, Festkörper-NMR, UV/Vis, MALDI-TOF) Methoden, Zetapotentialmessungen in wässeriger Phase und thermogravimetrischen Bestimmungen charakterisiert werden. info:eu-repo/classification/ddc/540 ddc:540 Aromatische Verbindungen Basizität Sol-Gel-Verfahren Solvatochromie Dipolarität/Polarisierbarkeit Poly(benzophenone-co-piperazine) Wasserstoffbrückenbindungen
25	Sulfur-doped Nanographenes Containing Multiple Subhelicenes Niu, Wenhui, Fu, Yubin, Komber, Hartmut, Ma, Ji, Feng, Xinliang, Mai, Yiyong, Liu, Junzhi 13 May 2022 (has links) In this work, we describe the synthesis and characterization of three novel sulfur-doped nanographenes (NGs) (1–3) containing multiple subhelicenes, including carbo[4]helicenes, thieno[4]helicenes, carbo[5]helicenes, and thieno[5]helicenes. Density functional theory calculations reveal that the helicene substructures in 1–3 possess dihedral angles from 15° to 34°. The optical energy gaps of 1–3 are estimated to be 2.67, 2.45, and 2.30 eV, respectively. These three sulfur-doped NGs show enlarged energy gaps compared to those of their pristine carbon analogues. info:eu-repo/classification/ddc/540 ddc:540
26	Enhancing hypothiocyanite production by lactoperoxidase – mechanism and chemical properties of promotors Gau, Jana, Furtmüller, Paul-Georg, Obinger, Christian, Arnhold, Jürgen, Flemmig, Jörg January 2015 (has links) Background: The heme enzyme lactoperoxidase is found in body secretions where it significantly contributes to the humoral immune response against pathogens. After activation the peroxidase oxidizes thiocyanate to hypothiocyanite which is known for its microbicidal properties. Yet several pathologies are accompanied by a disturbed hypothiocyanite production which results in a reduced immune defense. Methods: The results were obtained by measuring enzyme-kinetic parameters using UV–vis spectroscopy and a standardized enzyme-kinetic test system as well as by the determination of second order rate constants using stopped-flow spectroscopy. Results: In this study we systematically tested thirty aromatic substrates for their efficiency to promote the lactoperoxidase-mediated hypothiocyanite production by restoring the native ferric enzyme state. Thereby hydrophobic compounds with a 3,4-dihydroxyphenyl partial structure such ashydroxytyrosol and selected flavonoids emerged as highly efficient promotors of the (pseudo-)halogenating lactoperoxidase activity. Conclusions: This study discusses important structure-function relationships of efficient aromatic LPO substrates and may contribute to the development of new agents to promote lactoperoxidase activity in secretory fluids of patients. Significance: This study may contribute to a better understanding of the (patho-)physiological importance of the (pseudo-)halogenating lactoperoxidase activity. The presented results may in future lead to the development of new therapeutic strategies which, by reactivating lactoperoxidase-derived hypothiocyanite production, promote the immunological activity of this enzyme. info:eu-repo/classification/ddc/540 ddc:540 info:eu-repo/classification/ddc/610 ddc:610
27	Untersuchungen zur Synthese von Yohimban- und Campthoteca-Alkaloiden durch Domino-Knoevenagel-Hetero-Diels-Alder-Reaktion / Efforts toward the total synthesis of yohimban and campthoteca alkaloids via domino Knoevenagel-hetero-Diels-Alder reaction Klapa, Katharina Anna 17 January 2007 (has links) No description available. 540 Chemie Mathematics and Computer Science organische Synthese Domino-Reaktionen Alkaloide Yohimbin Camptothecin organic synthesis domino reactions alkaloids yohimbin camptothecin 35.50 Organische Chemie: Allgemeines 35.51 Organische Reaktionen Stereochemie 35.59 Heterocyclische Verbindungen 35.66 Terpene Steroide Alkaloide 35.68 Organische Verbindungen: Sonstiges 35.69 Organische Chemie: Sonstiges SUD 350: Hydrierungs- SUK 350: Amine -NH2- Amide Enamine Imine {Organische Chemie}

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