Eu（Ⅲ） Indirect Probe to Investigate Interaction of DOPA （3, 4, Di-Hydroxyphenylalanine） and Dopamine （3, 4-Dihydroxy Phenyl Ethyl Amine） Using Electrochemical Methods

Eu（ Ⅲ ） can be utilized as an indirect electrochemical probe to investigate the interaction of bio-molecules such as DOPA and Dopamine with Ca（ Ⅱ ） in vitro. The interaction of DOPA and Dopamine with Eu（ Ⅲ ）-Eu（ Ⅱ ） redox pair was investigated by electrochemical techniques. Both the neurotransmitters are structurally related and undergo interaction with Eu （Ⅲ ）. Eu （ Ⅲ ） coordinates with DOPA and Dopamine through five-member chelate tings via carboxylic oxygen and amino nitrogen. The electrode kinetic parameters viz, transfer coefficient （αna）, diffusion coefficient （D）, forward heterogeneous rate constant （ k^0 fh） were evaluated for Eu（ Ⅲ ）-DOPA/Eu（ Ⅲ ）-Dopamine. The results obtained were used to investigate the nature of interaction of Eu （Ⅲ） with muhi-donor biomolecules. The possible mechanism was also proposed.     

4，4’－二（二乙氨基）－二苯硫酮分光光度法测定痕量铜

本文系统地研究了４,４’－二（二乙氨基）－二苯硫酮（ＢＤＰＴＫ）与铜（Ⅰ）的显色反应,在ＴｒｉｔｏｎＸ－１００增溶作用下,其摩尔吸光系数可达９．７４×１０６Ｌ·ｍｏｌ（－１）·ｃｍ（－１）。这是迄今发现的关于铜的最灵敏的显色反应。该反应的一个突出优点就是可以允许１０６倍的Ｎｉ存在。据此拟定了在水相直接测定痕量铜的分光光度法,并试用于高纯镍和血清样中痕量铜的测定,取得满意结果     

(3R,4S)-3-[4-(4-fluorophenyl)-4-hydroxypiperidin-1-yl]chroman-4,7-diol: a conformationally restricted analogue of the NR2B subtype-selective NMDA antagonist (1S,2S)-1-(4-hydroxyphenyl)-2-(4-hydroxy-4-phenylpiperidino)- 1-propanol

(1S,2S)-1-(4-Hydroxyphenyl)-2-(4-hydroxy-4-phenylpiperidino)-1-propanol (CP-101,606, 1) is a recently described antagonist of N-methyl-D-aspartate (NMDA) receptors containing the NR2B subunit. In the present study, the optimal orientation of compounds of this structural type for their receptor was explored. Tethering of the pendent methyl group of 1 to the phenolic aromatic ring via an oxygen atom prevents rotation about the central portion of the molecule. Several of the new chromanol compounds have high affinity for the racemic [3H]CP-101,606 binding site on the NMDA receptor and protect against glutamate toxicity in cultured hippocampal neurons. The new ring caused a change in the stereochemical preference of the receptor-cis (erythro) compounds had better affinity for the receptor than the trans isomers. Computational studies suggest that steric interactions between the pendent methyl group and the phenol ring in the acyclic series determine which structures can best fit the receptor. The chromanol analogue, (3R,4S)-3-[4-(4-fluorophenyl)-4-hydroxypiperidin-1- yl]chroman-4,7-diol (12a, CP-283,097), was found to possess potency and selectivity comparable to CP-101,606. Thus 12a is a new tool to explore the function of the NR2B-containing NMDA receptors.     

Acid dissolution of willemite (Zn,Mn)2 SiO4) and hemimorphite (Zn4Si2O7(OH)2 H2O)

The influence of temperature, pH, acid type, and surface area on the kinetics of the acid dissolution of natural and synthetic willemites and natural hemimorphites has been investigated. Specific rate constants, based upon areas determined by krypton adsorption measurements, were estimated from the experimental data obtained. For both willemite and hemimorphite, the rates of dissolution in different acids are shown to be related to the relative strengths of zinc-acid anion complexes. The reactivity of willemite toward acids increases with increasing replacement of zinc by manganese. Mixed chemical/diffusion control is responsible for the observed rates of willemite dissolution under the conditions studied (HNO₃, HCl, HClO₄, H₃PO₄, H₂SO₄, pH 0.31 to 3.00,T 21 to 94 °C). Estimates of the relative contributions of chemical and diffusional resistances to the overall rate have been made for the dissolution of manganese-free willemite in sulfuric acid solutions. The experimentally measured rates have been demonstrated to be in reasonable agreement with predicted overall dissolution rates. Proposals are made regarding the nature of the diffusion and chemical steps involved in the dissolution process. Hemimorphite was found to be considerably more reactive than willemite and its dissolution is primarily diffusion controlled under the conditions studied (T 20 to 76 °C, pH 2 to 3.5). Formerly a Postgraduate Research Student, Department of Metallurgy and Materials Science, Royal School of Mines, Imperial College, London     

5,10,15-三(对氯苯基)20-丙氧苯基卟啉三乙基溴化铵显色剂与铜的显色反应

研究了新显色剂5,10,15三(对氯苯基)20丙氧苯基卟啉三乙基溴化铵与铜的显色反应。结果表明:在中性介质中,沸水浴加热10min形成1:1的络合物,λmax=417nm,在0～12μg/10mL范围内吸光度与铜浓度的关系符合比尔定律,表观摩尔吸光系数ε=3.58×105。该法具有灵敏度高及选择性好的特点,用于水样实际测定,结果满意。     

Biotransformation, excretion, and nephrotoxicity of the hexachlorobutadiene metabolite (E)-N-acetyl-S-(1,2,3,4, 4-pentachlorobutadienyl)-L-cysteine sulfoxide

The disposition of ethyl 4-(3,4-dimethoxyphenyl)-6,7-dimethoxy-2-(1,2,4- triazol-1-ylmethyl) quinoline-3-carboxylate (CAS 158146-85-1, TAK-603) after single oral dosing of 14C-labeled TAK-603 ([14C]TAK-603) at 10 mg/kg to rats and dogs was studied. In rats, the concentration of unchanged drug in plasma reached a peak (Cmax, 0.31 microgram/ml) 2 h (Tmax) after dosing of TAK-603 and declined biphasically with apparent half-lives (t 1/2 alpha, t 1/2 beta) of 1.5 and 3.6 h. In dogs, Tmax, Cmax, T 1/2 alpha, and t 1/2 beta were 1.7 h, 0.36 microgram/ml, 1.2, and 10.8 h, respectively. [14C]TAK-603 dosed orally was absorbed quantitatively in rats, while the extent of absorption in dogs was 54%. The bioavailability of TAK-603 was 53% and 42% in rats and dogs, respectively. In rats, 14C was distributed widely in various tissues, with relatively high concentrations in the liver, adrenal gland, and gut. The elimination of 14C from the thyroid was slower than that from other tissues. Unchanged TAK-603 and its pharmacologically active metabolite, M-I, which has the same potency as TAK-603, were distributed in articular soft tissues and synovial fluids, as target tissues, in rats and dogs, respectively. After oral administration of [14C]TAK-603, most of the 14C dosed was excreted within 48 h in rats and within 96 h in dogs. In both animals, a greater amount of the 14C dosed was excreted in feces than in urine. In biliary duct cannulated rats given [14C]TAK-603 intraduodenally, 69% of the dose was excreted in bile, and biliary 14C in part underwent enterohepatic circulation.     

Studies on NaLn(WO_4)_2 Single Crystals(Ln=La,Pr,Nd)

The crystals of NaLn(WO4)_2(Ln=La,Pr,Nd)are grown from a melt of LiCl-Na_2WO_4 flux by slowcooling method.The chemical analysis data show that the crystals are NaLa(WO_4)_2,NaPr(WO4)_2 andNaNd(WO_4)_2 respectively.The structures of the crystals are ascertained that they belong to scheelite structureof the tetragonal system with a space group of 14_1/a.The lattice parameters of the crystals have beencalculated.It is found that the cell volume of NaLn(WO_4)_2 crystals decrease with a decrease of Ln~(3 )radius.The bond distances and their angles in NaLa(WO_4)_2 and NaNd(WO_4)_2 are given.It is found that inaccordance with the decrease of ionic radii of Ln~(3 )due to increase of atomic number,the bond distances betweenLn-O,Ln-Ln and W-O decrease regularly.The infrared spectra of NaLn(WO_4)_2 are measured.Thetetrahedra characteristic absorptions of WO_4~(2-)are shown.The sensitization of host lattice is observed from theexcitation and fluorescent spectra of NaLa(WO_4)_2 and NaPr(WO_4)_2.     

三元配合物[RE(Gly)4(Im)(H2O)](ClO4)3(RE=La,Pr)的热化学研究

利用自行研制的新型恒温环境反应量热计,以2mol·L-1HCl做溶剂,分别测定了LaCl3·7H2O、PrCl3·6H2O、[La(Gly)4(Im)(H2O)](ClO4)3、[Pr(Gly)4(Im)(H2O)](ClO4)3、Im、NaClO4、Gly、NaCl在298.15K时的溶解焓,再通过设计的热化学循环求得化学反应的摩尔反应焓,利用这些结果和其它辅助数据,计算出两种配合物的标准摩尔生成焓分别为:ΔfH m{[Prm{[La(Gly)4(Im)(H2O)](ClO4)3,s}=-3459.3±0.2kJ·mol-1;ΔfH (Gly)4(Im)(H2O)](ClO4)3,s}=-3460.63±0.18kJ·mol-1。