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This paper presents research on the use of coumarin derivatives as fluorescent molecular probes for monitoring cationic and free radical photopolymerization processes, using for that purpose modern FPT method (Fluorescence Probe Technology). Literature review on the main trends of applications and spectroscopic properties of coumarin derivatives was described. In the following part of publication, relations between change of fluorescence characteristic and physicochemical changes occurring in the polymerizable composition, (both microviscosity and polarity) were explained. This article also presented the basic methodology of studies on the control of the photopolymerization reaction on-line and off-line, using fluorescence spectroscopy and parameters such as: fluorescence intensity ratio R, number of progress of the reaction β and molecular probe sensitivity S.
Selected benzo[b]furan and coumarin derivatives with proven and potential antibacterial, anticancer and antiarrhythmic activities have been investigated [1–3] (Figs. 1 and 2). The stereochemical description of their molecules in the solid and gas phase as well as intra- and intermolecular-interactions in crystals have been determined [4–6]. The structural studies of analyzed molecules indicated the planarity of the benzo[b]furan and coumarin ring systems. The oxygen or carbon atoms of the substituents, –OH, –OCH3, –C(=O)CH3 and –COO H, are nearly coplanar with the aromatic ring. The hydroxyl and acetyl groups, being in the ortho position, are coplanar with the aromatic ring and the formation of the intramolecular O–H…O hydrogen bond in all three states of matter is observed. Its strength is around 18 kcal/mol. Several conformers of studied compounds, differing in the orientation of the methoxy, acetyl and/or carboxyl groups, were analyzed. Next, the electrochemical method was used to synthesize novel copper and zinc complexes with the oxygen donor benzo[b]furan and coumarin derivatives. The Cu(II) and Zn(II) complexes have been obtained with carboxylic acids as ligands whereas hydroxy ligands reacted only with copper [6]. The geometry of metal-ligand interaction of new compounds has been determined using a single crystal X-ray crystallography and an X-ray absorption spectroscopy [7, 8]. The combination of these two methods revealed that for some compounds cation environment could depend on the form of the solid sample. In the microcrystalline zinc complexes (studied by EXAFS) the cation is penta-coordinated (ZnO5) with the Zn–O distances being ca 1.98(3) Ĺ. In the recrystallized complex (analyzed by the X-ray diffraction) it was found that zinc is tetra-coordinated (ZnO4). The Cu(II) cation in the singlecrystal form of the complex with the carboxylic acid 5 is penta-coordinated to the carboxylate groups and the ethanol molecule. The bridging COO – groups stabilize the dinuclear complex center Cu2O10. The powdered form of this complex is based on the Cu2O8 units, indicating the absence of the ethanol molecule in the coordination sphere. In the series of the Cu(II) complexes with the hydroxy derivatives of benzo[b]furan and coumarin a centrosymmetric coordination polyhedron of metal exhibits a square-planar geometry (CuO4). Two ligands are bonded to the copper cation via the acetyl and deprotonated hydroxyl O atoms.
Content available remote Pochodne kumaryny stosowane w detekcji enzymów
W artykule przedstawiono przegląd pochodnych kumaryny stosowanych w nowoczesnych metodach detekcji enzymów, ze szczególnym uwzględnieniem analizy produktów żywnościowych. Opisano również metodykę syntezy wybranych związków z tej grupy.
In this article are presented review of coumarin derivatives applied in novel methods of enzymes' detection, with particular taking into consideration analysis of food products. Here is also described synthesis of selected compounds belong to this group.
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