The ortho effect makes manganese(III) meso-tetrakis(N-methylpyridinium-2-yl)porphyrin a powerful and potentially useful superoxide dismutase mimic

The ortho, meta, and para isomers of manganese(III) 5,10,15, 20-tetrakis(N-methylpyridyl)porphyrin, MnTM-2-PyP5+, MnTM-3-PyP5+, and MnTM-4-PyP5+, respectively, were analyzed in terms of their superoxide dismutase (SOD) activity in vitro and in vivo. The impact of their interaction with DNA and RNA on the SOD activity in vivo and in vitro has also been analyzed. Differences in their behavior are due to the combined steric and electrostatic factors. In vitro catalytic activities are closely related to their redox potentials. The half-wave potentials (E1/2) are +0.220 mV, +0.052 mV, and +0.060 V versus normal hydrogen electrode, whereas the rates of dismutation (kcat) are 6.0 x 10(7), 4.1 x 10(6), and 3.8 x 10(6) M-1 s-1 for the ortho, meta, and para isomers, respectively. However, the in vitro activity is not a sufficient predictor of in vivo efficacy. The ortho and meta isomers, although of significantly different in vitro SOD activities, have fairly close in vivo SOD efficacy due to their similarly weak interactions with DNA. In contrast, due to a higher degree of interaction with DNA, the para isomer inhibited growth of SOD-deficient Escherichia coli.     

Cytotoxicity of new Ho(III) and Pr(III) complexes

New complexes of coumarin-3-carboxylic acid (HCCA) with Ho(III) and Pr(III) were synthesized and their structures and spectral properties were investigated by elemental analysis, IR, Raman and NMR measurements. According to the experimental data the complexes' formula and geometries were suggested. Vibrational frequencies, IR intensities and Raman activities as well as ¹H NMR chemical shifts of HCCA and its Ho(III) and Pr(III) complexes were presented. The comparative experimental vibrational and NMR analyses of both the ligand and the Ln(III) complexes predicted the bidentate binding to Ho(III) and Pr(III) through the deprotonated carboxylic oxygen and the carbonylic oxygen of the ligand. The cytotoxic/cytostatic properties of the ligand and the newly synthesized complexes of coumarin-3-carboxylic acid with Ho(III) and Pr(III) were tested by MTT reduction assay against two mouse tumor cell lines: melanoma B16 and fibrosarcoma L929. They were also tested for cytotoxicity against normal mouse peritoneal macrophages. The proliferation inhibitory effect of the complexes compared to that of the ligand proved their cytotoxic/cytostatic properties against both the tumor cell lines. In addition, the complexes were less cytotoxic against normal mouse macrophages and were able to modulate NO release by activated macrophages. The obtained results were in accordance with our previously published data concerning the activity of lanthanide(III) complexes with other coumarin derivatives.     

Studies on some lanthanide（Ⅲ） complexes with 4-hydroxyantipyrine

Seven new lanthanide（Ⅲ） complexes with 4-hydroxyantipyrine were synthesized. These complexes were characterized by elemental analysis, molar conductance, magnetic moment measurements, FT-IR, electronic and 1HNMR spectra, X-ray powder diffraction, and thermogravimetric studies. The ligand, 4-hydroxyantipyrine （hap）, contained carbonyl oxygen and hydroxyl oxygen as potential donor sites. On coordination, deprotonation occurred and as a result, hap acted as a monobasic bidentate ligand. A coordination number 6 was assigned to the lanthanide（Ⅲ） ions in these complexes with orthorhombic structure. All the complexes were thermally stable-150℃ and underwent decomposition in three stages with the formation of Ln2O3 as the final residues.     

Resonance Raman spectra of iron(III)-, copper(II)-, cobalt(III)-, and manganese(III)-transferrins and of bis(2,4,6-trichlorophenolato)diimidazolecopper(II) monohydrate, a possible model for copper(II) binding to transferrins

Fe(III), Cu(II), Co(III), and Mn(III) complexes of ovo- and human serum transferrins show resonance enhanced Raman bands near 1600, 1500, 1270, and 1170 cm-1 upon excitation with laser frequencies which fall within the visible absorption bands of those metalloproteins. Comparison of the visible absorption and resonance Raman spectra of the Cu(II)-transferrin complexes with those for the Cu(II) model compound, bis(2,4,6-trichlorophenolato)diimidazolecopper(II) monohydrate, indicates that the resonance Raman bands are due to enhancement of phenolic vibrational modes. For the model (Cu(II) compound, a normal coordinate analysis was used to aid our assignment of the observed resonance bands at 1562, 1463, 1311, and 1122 cm-1 to A1 vibrational modes of the 2,4,6-trichlorophenolato moiety. These assignments are consistent with those made for Cu(II)-transferrins. The latter assignments were based upon calculated A1 frequencies for p-methylphenol (Cummings, D.L., and Wood, J.L. (1974), J. Mol. Struct. 20, 1). The wavelength shifts in the resonance bands for the model compound from those for Cu(II)-transferrins are due to the influence of the chloro substituents on the planar vibrations of phenol. These results clearly identify tyrosine as a ligand in copper binding to transferrins.     

Synthesis and crystal structures of La(III), Y(III) complexes of homoveratric acid with 1,10-phenanthroline

Two three-dimensional complexes [Ln(DMPA)₃phen]₂ (HDMPA=3,4-dimet hoxyphenylacetic acid, homoveratric acid; Ln=La, Y; phen=1,10-phenanthroline) were synthesized under hydrothermal conditions and characterized with IR and emission spectra. The crystal structures were determined with single crystal X-ray diffraction method. The two compounds were isostructural, and 3D supramolecule architectures were formed by hydrogen bonds and π–π stacking interactions. They strongly emitted upon excitation due to π^*→π transition of the ligands.     

铜锰渣酸浸及选择性硫化沉淀法回收铜工艺

系统开展了铜锰渣的H2SO4浸出及酸浸液Na2S2O3选择性沉铜研究,通过单因素实验,分别探究了2个工艺过程的影响因素.实验结果表明:铜锰渣酸浸的较优条件为:H2SO4用量200 g/L,液固体积质量比(mL/g)7:1,反应温度80℃,反应时间2 h,该条件下铜、钴、锌、锰的浸出率分别为99.81％,99.54％,9...     

Enthalpies of formation of liquid (copper + manganese) alloys

The enthalpies of formation of liquid (Cu + Mn) alloys were measured in the isoperibolic heat-flux calorimeter at 1573 K in the entire range of compositions. The integral molar enthalpy of mixing was found to be negative in the range of molar fractions 0 < x _Mn < 0.31, with ΔH(min) = −0.69 ± 0.27 kJ mol⁻¹ at x _Mn = 0.12, and positive in the range 0.31 < x _Mn < 1, with ΔH(max) = 3.67 ± 0.36 kJ mol⁻¹ at x _Mn = 0.75. Limiting partial molar enthalpies of manganese and copper were calculated as = −18.0 ± 6.6 kJ mol⁻¹ and = 29.1 ± 4.9 kJ mol⁻¹, respectively. The results are discussed in comparison with the thermodynamic data available in the literature and the equilibrium phase diagram.     

1-[(2,3,4-三羟基苯)偶氮]-4-苯甲酸分光光度法测定铋的研究与应用

研究了1-[(2,3,4-三羟基苯)偶氮]-4-苯甲酸(TKAB)与铋的显色反应,试验了5种不同表面活性剂及1种混合表面活性剂的增敏作用,选定Bi(Ⅲ)-TKAB-CTMAB显色体系.该体系在pH1.45～2 80形成稳定的红棕色络合物,在445nm处有最大吸收,表观摩尔吸光系数ε=5.45 ×104.铋的质量浓度在0～20μg/10mL范围内符合比尔定律.用于铜合金中痕量铋的直接测定,结果满意.     

Anti-inflammatory activity of (cresoxyacetate)copper complexes]

In groups of mononuclear aqua(cresoxyacetato)copper(II) complexes of the composition [Cu(ROCH2COO)2(H2O)n] (R= 2- and 3-methylphenyl, n = 2; 4-methylphenyl, n = 3) and binu- clear phenazone(o-, m-, p-cresoxyacetato)copper(II) complexes of the composition [Cu2(ROCH2COO)4(phz)2] the anti-inflammatory activity was assayed in rat paw carrageenan-induced edema. The effects of the complexes were compared with each other and with those of the free acids. Salicylic acid and its cupric salt (tetrahydrate) were used as standards of comparison. All copounds were applied i.p. in a single dose of 50 mumol/kg body weight (calculated for the RCOO-fragment). In general, all Cu(II) complexes tested were clearly more effective (71-88%) than the corresponding free isomeric cresoxyacetic acids (47, 37, 45%), with the exception of diaquabis (o-cresoxyacetato)copper(II) complex (43%). Copper(II) salicylate tetrahydrate (57%) and salicylic acid (41%) were less active, too. The observed activities of complexes are discussed in relation to their structures.     

Purification of manganese solutions containing copper and zinc by liquid-liquid extraction,using di-(2-ethylhexyl) phosphoric acid

Abstract

Extraction data are shown for the purification of a relatively high-grade, manganese sulphate solution containing zinc and copper as impurities. Copper can be removed by solvent extraction, using the mixed extractant consisting of the substituted oxime LIX-63 by General Mills Inc., together with di-(2-ethylhexyl) phosphoric acid in the pH range of 0.8 to 1.5. Zn has been shown to be selectively extracted by di-(2-ethylhexyl) phosphoric acid from such a solution in the pH range 3 to 5. Manganese and Zn can also be coextracted in the pH range 5.0 to 5.5. Processing costs for the liquid-liquid extraction of zinc are also given. The purified manganese sulphate solution would likely be amenable to the production electrolytic-grade managanese.

R;amp;#x00E9;sumé

Les auteurs donnent les résultants de la purification d'une solution à teneur relativement élevée de sulfate de manganése contenant, comme impuretés, du zinc et du cuivre. Le cuivre peut être enlevé par un solvant en utilisant un composé mixte d'oxyme LIX-63 de General Mills Inc. et d'acide phosphorique di-(2-éthylhexyl) avec un pH compris entre 0.8 et 1.5. Le zinc est extrait sélectivement par l'acide phosphorique di-(2-éthylhexyl) de cette solution avec un pH de 3 à 5. Le manganèse et le zinc peuvent également étre extraits simultanément quand le pH est de 5 à 5.5. Le coût du procédé pour l'extraction en milieu liquide du zinc est donné. La solution purifiée de sulfate de manganèse peut être amenée à la production de manganèse électrolytique.     

一价铜卤化物的设计合成与晶态结构研究

以1,2-双(二苯基膦)乙烷(dppe)、1,4-双(二苯基膦)丁烷(dppb)和卤化亚铜作为初始原料,合成得到1个三核铜(I)溴化物[{Cu2(μ-dppe)(μ-Br)2}(μ-dppe)2CuBr](1)和1个双核铜(I)碘化物[{Cu(dppb)I}2(μ-dppb)](2). X-射线单晶衍射表明:配合物1为三核铜配合物,Cu1和Cu2两原子采用常见的四配位方式,分别与2个Br原子和2个P原子连接构成1个变型四面体,而Cu3原子采取三配位模式,与1个Br和2个P原子相连接形成1个平面三角形, Cu1、Cu2和Cu3这3个铜原子又共同构成了1个近似等腰的平面三角形;配合物2为双核铜配合物,3个dppb配体表现出2种配位方式:2个以二齿螯合方式分别与1个Cu原子连接,1个以桥联方式与2个相同的{Cu(dppb)I}砌块相连接.     

Synthesis and characterization of terbium(III)-pyromellitic acid (H4L)-1,10-phenanthroline (phen) luminescent complex

The terbium(III)-pyromellitic acid(H₄L)-1,10-phenanthroline(phen) luminescent complex was synthesized using a co-precipitation method. The chemical composition of the synthesized complex was speculated to be Tb₄L₃(phen)_0.075·10H₂O by elemental analysis, inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and Fourier-transform infrared spectroscopy (FT-IR). The X-ray diffraction analytic results indicated that the synthesized complex is a new crystalline complex, whose structure was different from those of other two ligands. The scanning electron microscopy analytic results showed that the product was of spherical crystals with good dispersion property, and the mean diameter of the spheres was about 1-2 μm. The TG-DTA result showed that the complex had good stability below 489 °C. PL spectra showed that the complex emitted characteristic green fluorescence of Tb(III) ion under ultraviolet excitation.     

Microwave assisted synthesis, spectroscopy and biochemical aspects of lanthanum(Ⅲ) and praseodymium(Ⅲ) complexes with oxadiazole functionalised dithiocarbazinates

The new lanthanum (Ⅲ) and praseodymium (Ⅲ) complexes of the general formula [Ln(L)3] (Ln=La(Ⅲ) or Pr(Ⅲ); LK=potassium salt of dithiocarbazinates) were prepared by both, conventional thermal and by the use of microwave technology. Elemental analyses, elec-trical conductance, magnetic moment and electronic, infrared, far-infrared, 1H and 13C NMR spectral studies were used to characterize the complexes. The molecular weights of few complexes were determined by FAB-mass spectra. Nephelauxetic ratio, covalency parameter and bonding parameter for these complexes were also calculated. The probable structures of the complexes were proposed. The antifungal and antibacterial activities of the complexes were evaluated. The activities were correlated with the structures of the compounds.     

Twenty-four-hour heart preservation using continuous cold perfusion and copper (II) complexes

Spinocerebellar ataxia 7 (SCA7) is a neurodegenerative disorder characterized by degeneration of the cerebellum, brainstem and retina. The gene responsible for SCA7, located on chromosome 3p, recently was cloned and shown to contain a CAG repeat in the coding region of the gene, that is expanded in SCA7 patients of French origin. We examined the SCA7 repeat region in four Swedish SCA7 families as well as in 57 healthy controls. All Swedish SCA7 patients exhibited expanded CAG repeats with a strong negative correlation between repeat size and age of onset. The repeat length in SCA7 patients ranged from 40 to >200 repeats. The largest expansion was observed in a juvenile case with an age of onset of 3 months, and represents the longest polyglutamine stretch ever reported. In patients with 59 repeats or more, visual impairment was the most common initial symptom observed, while ataxia predominates in patients with <59 repeats. Two of the Swedish SCA7 families analysed in this study were shown to be related genealogically. The other two SCA7 families could not be traced back to a common ancestor. All four families shared the same allele on the disease chromosome at a locus closely linked to SCA7, suggesting the possibility of a founder effect in the Swedish population.     

Behavior of antimony(III) during copper electrowinning in chloride solutions

Contamination of cathodic copper by Sb during electrowinning in chloride solutions is a surface phenomenon. A digitized scanning electron microscopy (SEM) micrograph indicates that the Sb is concentrated on the surface of the cathode. Energy-dispersive X-ray (EDX) analysis reveals that the Sb-containing layer is a complex salt of Cu, Sb, Cl, and O. Electrochemical measurements show-that the adsorption of Sb or Cu species decreases with the increase of acidity of the solution when the solution contains antimony chloride or cuprous chloride. The adsorption increases with the increase of the acidity when the solution contains both Sb and Cu. The discharge of cuprous ions in the adsorbed complex salt releases antimonious ions and then forms a new layer of the complex salt with cuprous ions from the solution. This newly formed complex salt is readsorbed on the surface of the cathode. Thus, Sb concentrates on the surface of the cathode instead of being evenly distributed throughout the copper product. This suggested mechanism also explains the fact that the presence of Sb in the electrolyte enhances the electrodeposition of Cu.