新型含葡萄糖基手性Salen配体及其Mn3+、Fe3+、Co2+、Cu3+配合物的合成与表征

A novel chiral Salen ligand with a glucose moiety was synthesized from the condensation of 1,2:5,6-di-O-isopropylidene-3-O-methylene-[5-(3-tert-butyl-2-hydroxy benzaldehyde)]-α-D-glucofuranose with (1R,2R)-1,2-diaminocyclohexane. Several chiral complexes of Mn³⁺, Fe³⁺, Co²⁺ and Cu²⁺ were prepared from this ligand. Both the ligand and the complexes were characterized by elemental analysis, NMR, IR, MS, and UV-Vis.     

Simultaneous determination of zinc and copper(II) with 1-(2-pyridylazo)2-naphthol in micellar media by spectrophotometric H-point standard addition method

The H-point standard addition method (HPSAM) was applied to handling spectrophotometric data for simultaneous determination of Zn²⁺ and Cu²⁺ or selective determination of Zn²⁺ in the presence of Cu²⁺. The ligand 1-(2-pyridylazo)2-naphthol (PAN) and its metal complexes (Zn-PAN and Cu(II)-PAN) were made water-soluble by the neutral surfactant Triton X-100, and therefore, no extraction with organic solvents was required. The method is based on the difference in absorbance of formed complexes between Zn²⁺ and PAN, at two different wavelengths at pH = 9.2. The formation of both the complexes was complete within five minutes. Zn²⁺ can be determined in the range of 0.2–25 μg/mL with satisfactory accuracy and precision in the presence of excess of Cu²⁺ and most other metal ions. Interference effects of common anions and cations were studied. Under working conditions, the proposed method was successfully applied to the simultaneous determination of Zn²⁺ and Cu²⁺ in several real and synthetic mixtures with different concentration ratio of Zn²⁺ and Cu²⁺. The text was submitted by the authors in English.     

锌(Ⅱ)-氨基酸水杨醛席夫碱-α-氨基酸三元配合物的稳定性

The stability constants of binary complexes of Zn(Ⅱ)-α-amino acid and ternary complexes of Zn(Ⅱ)-N-Salicylideneaminio acid (ligand A)-α-amino acid(ligand B) at (25±0.1)℃ and in the presence of 0.1 mol·L^-1 KNO₃ have been determined by pH method. The α-amino acid(Aa) used were Glycine(Gly), L-Serine(Ser), L-Leucine(Leu), L-Proline(Pro) and L-Phenylalanine(Phe). It was found that the linear free energy relationship (LFER) exists nicely between the following parameter pairs logβ₁₀₂ and pK^B₂, logβ₁₁₁ and pK^B₂, and logβ₁₁₁ and pK^A₂. The ΔlgK was used to characterize the stability of ternary complexes related to the stability of parent binary complexes. The hydrophobic interaction between ligands in the ternary complexes was studied.     

外源Cu2+与烟草CuZnSODⅢ的相互作用

In this paper， we have studied the interaction of CuZnSODⅢ and Outer-Copper， enzyme activity experiments expressed that 0.1mmol·L^-1 Cu²⁺ addition reduced the enzyme activity sharply， but this reduced action had not been found for the additions of 0.1mmol·L^-1 1∶1 Cu²⁺ and Zn²⁺， and 0.1mmol·L^-1 Zn²⁺， respectively. This was due to the Cu²⁺ exchanged the Zn²⁺ in CuZnSODⅢ，and it was proved by the experiment of determination of metal content. Meanwhile， the static fluorescence quenching mechanism revealed the exist of molecular complex of CuZnSOD with Cu²⁺. The binding constant was obtained from lineweaver-burk and double-lg plot. The distance of active site to Trp is about 2.83nm， was calculated according to F?rster theory.     

α-十四烷基-DOTA及其钆(Ⅲ)螯合物的合成与表征(英)

Synthesis and characterization of the ligand, [10-(α-tetradecylcarboxymethyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid, H₄L] and its Gd(Ⅲ) chelate are described. Protonation constants for H₄L(lgK_i^H = 10.62, 9.50, 4.74, 4.12) and the stability constant for GdL^-(lgK_GdL^-= 24.60) were determined by potentiometric titrations. The results obtained show that the basicity of the ligand is not significantly altered and the ligand still maintains the strong chelating properties of the parent DOTA after introduction of a linear chain tetradecyl group at the acetic side chain of DOTA.     

2-十四烷基-DTPA及其钆(Ⅲ)螯合物的合成与表征(英)

Synthesis and characterization of the ligand, [2-tetradecyl-3,6,9-tris(carboxymethyl)-3,6,9-triazaundecan-1,11-dioic acid, H₅L] and its Gd(Ⅲ) chelate are described. Protonation constants for H₅L (lgK_i^H = 10.80, 8.40, 4.30, 2.80, 2.15) and the stability constant for GdL^2- (lgK_GdL^2-= 22.75) were determined by potentiometric titration and are similar with the related values of DTPA and Gd-DTPA respectively. The results obtained show that the basicity of the ligand and the stability constant of its Gd(Ⅲ) chelate are not obviously altered after introduction of a linear chain tetradecyl group at the terminal acetic acid residue of DTPA.     

手性双核Salen配合物的合成与谱学性质

Six novel chiral dinuclear Salen complexes [Cu₂L₁·H₂O (3a), Cu₂L₂(3b), Ni₂L₁·2H₂O (4a), Ni₂L₂(4b), Mn₂Cl₂L₁·H₂O (5a), Mn₂Cl₂L₂ (5b)] have been synthesized(L₁ and L₂ are chiral dimeric Salen ligands with different chain length which were synthesized from (R,R)-diaminocyclohexane, salicylaldehyde, 4,4′-(1,10-decaneoxy)salicylaldehyde, 4,4′-(1,6-hexyloxy)salicylaldehyde). These compounds were charactered by elemental analysis, ¹H NMR, FT-IR, UV-Vis and CD spectra. The FT-IR, UV-Vis and CD spectra were discussed and compared with those of monomeric ligand and complex in detail. It was found that the spectra properties of compounds of different chain length were almost alike, and the properties of dimeric and monomeric compound were similar too. Furthermore Cotton effect and Cotton split of CD spectra of these chiral compounds were explained by the exciton interaction theory. It seemed that the direction of Cotton split depend on the configuration of diaminohexane. (R,R)-diaminohexane determine the chirality of Salen compounds as negative, and the positive and negative component of Cotton split lie at higher and lower energy respectively.     

金属离子与卟啉的嵌入反应动力学研究——邻苯二甲酸缓冲溶液中溴化间-四(N-乙酸甲酯基-3-吡啶基)卟啉与Cu(Ⅱ)的配位反应

Kinetics of the coordination reaction of tetrakis(N-carbomethoxymethyl-3-pyridyl) porphyrin(abbr. H₂T_β-N-ACMSPyP) with Cu(Ⅱ) ion has been studied in o-phthalic acid buffer system in an ionic strength of 0.5mol·dm^-3(KCI) at 35.0±0.1℃.The reaction is catalyzed by o-phthalic ion. The effect of concentration of the cata-lyst, metal ion and pH value of solution was discussed. The kinetics equation of the reaction were obtained as d[CuP⁴⁺]/dt=16.15{(1.0+3.35×10⁵[PT^2-]²)/1.0+1.57×10^-4[H⁺]²}[Cu²⁺][P]_T. The mechanism of the reaction was proposed. The deformation of the ring of porphyrins is the general condition in the reaction.     

Dioxygen reactivity of laccase

A study was carried out on the dioxygen reactivity of the laccases from Trametes villosa, Rhizoctonia solani, Myceliophthora thermophila, Scytalidium thermophilum, and Coprinus cinereus. At pH 5.5, these laccases showed an apparently constant K _m (about 20–50 μM) for O₂ with either 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) or methyl syringate as the reducing substrate, in contrast to the k _cat , which varied up to 100-fold. O₂ reactivity of the Trametes and Myceliophthora laccases was also studied at various pH and NaF concentrations. The apparent K _m of Trametes and Myceliophthora laccases varied only slightly when pH changed from 3.0 to 8.0 or when the laccases were inhibited by F⁻ at pH 5.5, although the apparent k _cat were more significantly affected by both factors. The dependence of the apparent K _m on the source of laccase, pH, and F⁻ inhibition suggested that the fungal laccases might have a conserved O₂ pocket and that the F⁻ or OH⁻ inhibition might affect the O₂ reduction step (k _cat ) more than the O₂ binding step (K _m ) under steady-state conditions.     

L-苏糖酸锰的制备及标准生成焓

The pink powder of manganese L-threonate was obtained by extracting with alcohol the concentrated solution derived from the reaction between L-threonic acid solution prepared by double decomposition reaction of calcium L-threonate with oxalic acid and superfluous manganese oxide at 80℃ for certain time. The composition of the new compound was determined by chemical and elemental analyses and its formula fits Mn(C₄H₇O₅)₂·H₂O, the IR spectra indicated that Mn²⁺ in the compound coordinates to oxygen atom of the carboxyl group, while the proton of the carboxyl group is dissociated, it was assumed that the coordination number of Mn²⁺ was 4. The results of TG-DTG showed that the compound have fairish stability, the intermediate and final product of the thermal de-composition of the compound are Mn(C₄H₇O₅)₂ and MnO₂, respectively. The constant volume combustion energy of the compound, Δ_cE, were determined by a precise rotating-bomb calorimeter at 298.15K, it was (-3384.30±1.21)kJ·mol^-1, its standard enthalpy of Combustion,Δ_cH_m^?,and standard enthalpy of formation,Δ_fH_m^? , were calculated. They are (-3383.07±1.21)kJ·mol^-1 and (-2 571.68±1.63)kJ·mol^-1, respectively.