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Abstract  

Infrared spectroscopy, thermogravimetry and differential scanning calorimetry techniques were used to study the metal-amino acid interactions for adducts of the general formula CdCl2 nL (n=1.0 or 1.5 and L=histidine or cysteine). After characterization the thermal degradation process was kinetically followed by a non-isothermal method. The infrared data confirmed that the cation is coordinated the carboxylic oxygen atoms of the amino acid molecules. The thermogravimetric results indicated that the main step of the thermal degradation of all amino acid adducts is connected to the rupture of the metal-ligand bonds, to give the associated activation energies values of 77, 44, 55 and 41 kJ mol-1 for CdCl2 nL, n=1.0 and 1.5, for histidine and cysteine, respectively.

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Abstract  

Solid complexes of M(His)2Cl2 nH2O (M=Mn, Co, Ni, Cu) of MnCl26H2O, CoCl26H2O, NiCl26H2O, CuCl22H2O and L-α-histidine (His) have been prepared in 95% ethanol solution and characterized by elemental analyses, chemical analyses, IR and TG-DTG. The constant-volume combustion energies of the complexes have been determined by a rotating-bomb calorimeter. And the standard enthalpies of formation of the complexes have been calculated as well.

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Abstract  

The enthalpies of solution in water of RE(His)(NO3)3 H2O (RE=La—Nd, Sm—Lu, Y) were measured calorimetrically at 298.15 K, and the standard enthalpies of formation of RE(His)aq 3+ (RE=La—Nd, Sm—Lu, Y) were calculated. The plot of the enthalpies of solution vs. the atomic numbers of the elements in the lanthanide series exhibits the tetrad effect.

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material as they share the properties of both organic and inorganic materials. Marcy et al. [ 7 ] reported that the nonlinearity of l -histidine tetrafluoroborate was at least five times higher than that of KDP. In the light of this, a series of l

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]. The basic amino acid l -histidine has been widely studied with the discovery of promising nonlinear optical NLO material l -histidine tetrafluoroborate [ 12 ]. Recently, several new salts of l -histidine have been reported with excellent NLO

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Abstract  

The enthalpy change of formation reaction of cobalt(II) histidine (His) complex in water has been determined by a microcalorimeter, using cobalt chloride with L-α-histidinein the temperature range of 25~50C. On the basis of experimental and calculated results, three thermodynamics parameters (the activation enthalpies, the activation entropies, the activation free energies), the rate constant, three kinetic parameters (the activation energies, the pre-exponential constant and the reaction order) are obtained. The results show that the titled reaction easily took place in the studied temperature.

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Abstract  

The reaction thermodynamic and kinetic equations for the non-reversible reactions are established. The enthalpy change of formation reaction of manganese(II) histidine (His) complex in water has been determined by microcalorimetry, using manganese chloride with L-a-histidine at 298.15-323.15 K. The standard enthalpy of formation of Mn(His)2 2+(aq) has been calculated. On the basis of experimental and calculated results, three thermodynamics parameters (the activation enthalpy, the activation entropy and the activation free energy), the rate constants, along with three kinetic parameters (the apparent activation energies, the pre-exponential constant and the reaction order) are obtained. The results show that the reaction easily takes place over the studied temperature range. The solid complex Mn(His)2Cl24H2O was prepared and characterized by IR and TG-DTG.

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Orvosi Hetilap
Authors: Katalin Molnár, István Karádi, István Sugár, Zoltán Sápi, Márta Marschalkó, Éva Pálinger, Zsuzsanna Darvas, Péter Pócza, András Falus, András Vereczkei, and Judit Várkonyi

Bencsáth M., Pálóczi K., Szalai Cs. és mtsai: Histidine decarboxylase in peripheral lymphocytes of healthy individuals and chronic lymphoid leukemia patients. Pathol. Oncol. Res., 1998, 4 , 121–124. Szalai Cs

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Fitzsimons, C. P., Lazar-Molnar, E., Tomoskozi, Z., Buzas, E., Rivera, E. S., Falus, A. (2001) Histamine deficiency induces tissue-specific down-regulation of histamine H2 receptor expression in histidine

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. (1993) Interleukin 3 promotes histamine synthesis in hematopoietic progenitors by increasing histidine decarboxylase mRNA expression. Biochem. Biophys. Res. Commun. 192 , 167-173. Interleukin 3 promotes histamine synthesis in

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