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Summary  

Rare earth picrate (RE) complexes with L-lysine (Lys) were synthesized and characterized. Elemental analysis (CHN), EDTA titrations and thermogravimetry data suggest a general formula RE(pic)32Lys2H2O, where RE=La-Lu (without Pm) and Y, pic=picrate). IR spectra suggest that Lys is coordinated to the central ion through the nitrogen of the α-amino group. Parameters obtained from the absorption spectrum of the Nd compound indicated that the metal-ligand bonds are essentially electrostatic. Emission spectrum and biexponential behavior of the luminescence decay of the Eu compound suggest the existence of polymeric species. Thermogravimetric/derivative thermogravimetric (TG/DTG) and differential scanning calorimetry (DSC) curves of all complexes are very similar, with five events. The final products are the corresponding rare earth oxides and their X-ray diffraction patterns are identical to the calcinated oxides.</o:p>

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Abstract  

A new unsymmetrical solid Schiff base (LLi) was synthesized using L-lysine, o-vanillin and 2-hydroxy-l-naphthaldehyde. Solid lanthanum(III) complex of this ligand [LaL(NO3)]NO3·2H2O have been prepared and characterized by elemental analyses, IR, UV and molar conductance. The thermal decomposition kinetics of the complex for the second stage was studied under non-isothermal condition by TG and DTG methods. The kinetic equation may be expressed as: dα/dt=Ae−E/RT(1−α)2. The kinetic parameters (E, A), activation entropy ΔS # and activation free-energy ΔG # were also gained.

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Summary  

A new unsymmetrical Schiff base ligand (H2LLi) was synthesized using L-lysine, o-vanillin and salicylaladyde. Thorium(IV) complex of this ligand [Th(H2L)(NO3)](NO3)2 .3H2O have been prepared and characterized by elemental analyses, IR, UV and molar conductance. The thermal decomposition kinetics of the complex for the second stage was studied under non-isothermal condition by TG and DTG methods. The kinetic equation may be expressed as: dα/dt=A .e-E/RT.1/2 (1-α).[-ln(1-α)]-1. The kinetic parameters (E, A), activation entropy ΔS ¹ and activation free-energy ΔG ¹ were also calculated.

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Amino acids such as l -serine, l -threonine, l -phenylalanine, l -tryptophan, l -lysine, l -ornithine, l -arginine, l -valine, and l -leucine are widely used in medical practice, as drugs for parenteral and per-os feeding, in cattle breeding, and in poultry raising. It is shown that planar chromatography can separate these essential amino acids from accompanying amino acids contained in the culture liquids used for their manufacture. A method is proposed for quantitative determination of the concentration of the compounds by densitometric analysis. The method can be effectively used to check the various stages of amino acid production.

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JPC - Journal of Planar Chromatography - Modern TLC
Authors: Ágnes Móricz, Györgyi Horváth, Péter Molnár, Béla Kocsis, Andrea Böszörményi, Éva Lemberkovics, and Péter Ott

The composition of the essential oil of Thymus vulgaris L. has been determined by GC-FID and GC-MS. Because separation of thymol, carvacrol, and linalool, components of the essential oil, was more efficient by overpressured layer chromatography (OPLC) than by conventional thin-layer chromatography (TLC), the forced flow technique was used before biological detection. All three test compounds had antibacterial effect against the phytopathogenic bacterium Pseudomonas syringae pv. maculicola, in bioautography, although in essential oil thymol was present in sufficient quantity to produce an inhibiting zone in the adsorbent layer. In BioArena investigations, when reduced glutathione as a formaldehyde (HCHO) capturer was dissolved in the cell suspension before bioautographic exposure to the essential oil, the characteristic inhibiting activity of thymol and carvacrol against Bacillus subtilis soil bacteria was reduced, whereas the presence of the HCHO precursors NGmonomethyl-l-arginine or N ɛ-monomethyl-l-lysine enhanced their antibacterial effect. These results suggest that HCHO and its reaction products may be involved in the antibacterial activity of thymol and carvacrol.

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-tryptophan (13) (Roanal, Budapest, Hungary); dl -aspartic acid (2) (POCh, Gliwice, Poland); l -asparagine (4) (Ubichen Limited, Hampshire, Great Britain); dl -asparagine hydrate (5), d -glutamine (6) (Loba Feinchemie, Fischamend, Austria); l -lysine

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., Steiner, U. and Schönbeck, F. (1989): Induction of disease resistance by N ε η -trimethyl-L-lysine in bean plants against Uromyces phaseoli . J. Phytopathol. 126 , 253-256. Induction of disease resistance by Nεη-trimethyl-L-lysine

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Tyihák, E., Trézl, L., Rusznák, I. (1980) Spontaneous N-epsilon-methylation of L-lysine by formaldehyde. Pharmazie 35 , 18–20. Rusznák I. Spontaneous N-epsilon-methylation of L-lysine

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Behr-Roussel D, Rupin A, Simonet S, Bonhomme E, Coumailleau S, Cordi A, Serkiz B, Fabiani JN, Verbeuren TJ: Effect of chronic treatment with the inducible nitric oxide synthase inhibitor N-iminoethyl-L-lysine or with L-arginine on progression of

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