meso-四(4-甲基-3-磺基苯)卟啉与镍显色反应的研究

本文研究了meso-四(4-甲基-3-磺基苯)卟啉[T(4M-3SP)P]与镍(Ⅱ)的显色反应.在表面活性剂氯化十六烷基吡啶(CPC)与吐温-60,镉盐和咪唑存在下,在pH8.0～9.0的弱碱性介质中,沸水浴加热,镍(Ⅱ)与T(4M-3SP)P形成灵敏度很高的1:1配合物,ε_(418)=2.27×10~5.在0～1.5μg Ni(Ⅱ)/10ml范围内符合比尔定律.应用本法测定了工业废水及合金中低含量镍,获得了满意的结果.     

新试剂5-(4-胂酸基苯偶氮)-8-氨喹啉与铜的显色反应及应用研究

本文研究了新显色剂5-(4-胂酸基苯偶氮)-8-氨基喹啉(APAQ)与铜(Ⅱ)的显色反应.在溴化十六烷基三甲铵(CTMAB)存在下,试剂与铜(Ⅱ)形成1:3的蓝紫色络合物,λmsx=580nm,摩尔吸光系数为8.9×10~4.铜量在0～15μg/25ml范围内遵守比尔定律.方法已用于锌、铝合金中铜的测定,结果良好.     

1-(2-羟基3,5-二硝基苯基)-3-[4-(苯基偶氮)苯基]-三氮烯与镍的显色反应及其分析应用

研究了新合成的 1-( 2-羟基-3,5- 二硝基苯基 )- 3-[4 -(苯基偶氮 )苯基 ] - 三氮烯 (HDNPAPT)试剂与镍的显色反应。在Na2 B4 O7 NaOH介质中 (pH10. 0～ 10. 6)及乳化剂OP存在下 ,镍与HDNPAPT形成稳定的 1:1红色络合物 ,λmax=5 45nm ,表观摩尔吸光系数ε545=1.45× 10 5,镍浓度在 0～ 8μg/2 5mL范围内符合比尔定律。拟定的新方法已应用于铝合金中微量镍的测定 ,结果满意     

4-(4-氯苯重氮氨基)-4'-硝基偶氮苯的合成及其与镉(Ⅱ)的显色反应

合成了一种新显色剂4-(4-氯苯重氮氨基)-4'-硝基偶氮苯(简称CDANA),并研究了该试剂与Cd(Ⅱ)的高灵敏显色反应。在60~65℃温度下,亚硫酸氢钠与甲醛反应半小时之后滴入苯胺生成苯胺基甲基磺酸钠,另将硝基苯胺重氮化得到重氮盐溶液滴入苯胺基甲基磺酸钠中得到4'-硝基-4-氨基偶氮苯,然后将其滴入氯苯胺重氮化后的重氮盐溶液中,得经红外光谱检验和元素分析证实的目标产物。分光光度的研究结果表明,在Triton X-100存在下,于pH 10.5的Na2B4O7-NaOH缓冲介质中,镉(Ⅱ)与试剂形成1∶2的橙红色络合物,其最大吸收波长位于558 nm处,表观摩尔吸光系数为1.42×105L.mol-1.cm-1,镉(Ⅱ)的质量浓度在0~0.75μg/mL范围内服从比尔定律。所拟方法用于废水中微量镉的直接测定,结果与原子吸收光谱法一致。     

2-(2-苯并咪唑基)-6-甲基吡啶铜(Ⅰ) 铁(Ⅱ) 异双核配合物的合成与表征

以1, 1′-双(二苯基膦) 二茂铁(dppf)、2-(2-苯并咪唑基)-6-甲基吡啶(Hbmp) 和[Cu (CH₃CN)₄](ClO₄) 作为起始原料,合成得到一个铜(Ⅰ) 铁(Ⅱ) 杂金属双核配合物[Cu (Hbmp)(dppf)](ClO₄)(1). X-射线单晶衍射结果表明:配合物1是一个铜(Ⅰ) 铁(Ⅱ) 异双核配合物,其中铜(Ⅰ) 离子以四配位方式,分别与2个氮原子和2个磷原子相连接形成一个变形的四面体构型,而铁(Ⅱ) 离子镶嵌在2个环戊二烯基之间构成一个交错式夹心饼干构型.配合物1在355~460 nm有一个弱的低能量宽吸收峰,来源于铜(Ⅰ) 离子到Hbmp配体的金属到配体电荷转移跃迁(MLCT),含有一些dppf到Hbmp的配体到配体电荷转移跃迁(LLCT).      

1-(2-吡啶基)-5-苯基-3-(2-呋喃基)甲分光光度法测定锌

锌的分光光度测定方法较多,显色剂也很多,但选择性较差.甲(?)类试剂是有色金属的优良显色剂,近年在甲(?)骨架上接上不对称基、杂环基等,可以改善这类试剂的选择性和灵敏度.我们新合成的1-(2-吡啶基)-5-苯基-3-(2-呋喃基)甲(?)(PPFF)就是含有呋喃基的不对称甲(?),其合成反应式如下:它能与锌结合成较稳定的络合物,在吐温-20存在下,可在水溶液中进行光度测     

1,2-双(1′-苯基-3′-甲基-5′-氧代吡唑-4′-基)乙二酮-〔1,2〕与三正辛基氧化膦协同萃取RE(Ⅲ)的性能和机理研究

研究了 1,2 -双 ( 1′-苯基 - 3′-甲基 - 5′-氧代吡唑 - 4′-基 )乙二酮 -〔1,2〕( H2 A )与三正辛基氧化膦 ( TOPO )协同萃取 RE( ) ( RE=L a、Pr、Nd、Gd、Dy和 Y)的性能。通过考察萃取剂浓度、溶液酸度和温度对 RE( )萃取平衡的影响 ,确定了萃取机理和萃合物组成 ,求得了半萃取 p H1 /2 值和萃取反应平衡常数 Ks.e.。     

1-(2,6-二氯-4-硝基苯)-3-(4-硝基苯)-三氮烯分光光度法测定钴

研究了新试剂1-(2,6-二氯-4-硝基苯)-3-(-4-硝基苯)-三氮烯(DCNPNPT)与钴(Ⅱ)显色反应的适宜条件.在表面活性剂Triton X-100存在下,Na2B4O7-NaOH缓冲液(pH.9.3)介质中,钴(Ⅱ)与DCNPNPT形成黄色络合物(12),其最大吸收波长为545nm,用双峰双波长法测定络合物的表观摩尔吸光系数ε=1.08×105,钴在0～240μg/L范围内符合比尔定律.此法已用于VB12针剂和矿样中微量钴(Ⅱ)的测定,结果满意.     

1，2-双(1′-苯基-3′-甲基-5′-氧代吡唑-4′-基)乙二酮-[1，2]与三正辛基氧化膦协同萃取RE(Ⅲ)的性能和机理研究

研究了1，2-双(1′-苯基-3′-甲基-5′-氧代吡唑-4′-基)乙二酮-[1，2](H     

1,6-双(1′-苯基-3′-甲基-5′-氧代吡唑-4′-基) 己二酮与UO_2(Ⅱ),Th(Ⅳ)及Ce(Ⅳ)的配合物合成及性质

本文用电导滴定和pH滴定法研究了乙醇—水液溶中UO_2(Ⅱ),Th(Ⅳ)及Ce(Ⅳ)与1,6—双(1′苯基-3′-甲基-5′-氧代吡唑-4′-基)已二酮的配合反应。合成了固态配合物:UO_2L·H_2O,ThL_2·2H_2O和Ce_2L_3(NO_3)_2·4H_2O,研究了它们的UV,IR,~1HNMR,荧光光谱及热稳定性。     

(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.     

N-[4-(1,1''-biphenyl)methyl]-4-(4-thiomorpholinylmethyl) benzenamines as non-oxazolidinone analogues of antimycobacterial U-100480

Twenty-three patients underwent conventional arteriography and 3D contrast enhanced magnetic resonance angiography explorations. The study was limited to the iliofemoral arteries (13 segments for each patient). Each segment was classified as having 0-49%, 50-99% or 100% stenosis. Overall results were excellent with K = 0.822, sensitivity 92% and specificity 93%. Segment by segment analysis corroborated the overall results except for the internal iliac arteries and the deep femoral arteries, demonstrating the limitations of this technique in this series.     

Preparation and antirheumatic activity of optically active 2-acetylthiomethyl-4-(4-methylphenyl)-4-oxobutanoic acid (KE-298)

2-Acetylthiomethyl-4-(4-methylphenyl)-4-oxobutanonic acid (KE-298) is an antirheumatic agent. To elucidate the effects of optically active KE-298, we resolved the racemic acid and obtained the two optical isomers. (+)-KE-298 was converted to the 4-bromobenzyl ester derivative and the absolute structure was confirmed as (S) by X-ray crystallographic analysis. The pharmacological activities of the optical isomers and racemic KE-298 were compared by using the characteristic tests for KE-298. Though (+)-KE-298 showed a stronger suppressive effect on rat adjuvant arthritis than (-)-KE-298, no difference between the two isomers was detected in in vitro tests (enhancing effect on lymphocyte transformation, IL-1 antagonistic effect).     

Dual inhibition of human type 4 phosphodiesterase isostates by (R, R)-(+/-)-methyl 3-acetyl-4-[3-(cyclopentyloxy)-4-methoxyphenyl]-3- methyl-1-pyrrolidinecarboxylate

Purified recombinant human type 4 phosphodiesterase B2B (HSPDE4B2B) exists in both a low- and a high-affinity state that bind (R)-rolipram with Kd's of ca. 500 and 1 nM, respectively [Rocque, W. J., Tian, G., Wiseman, J. S., Holmes, W. D., Thompson, I. Z., Willard, D. H., Patel, I. R., Wisely, G. B., Clay, W. C., Kadwell, S. H., Hoffman, C. R., and Luther, M. A. (1997) Biochemistry 36, 14250-14261]. Since the tissue distribution of the two isostates may be significantly different, development of inhibitors that effectively inhibit both forms may be advantageous pharmacologically. In this study, enzyme inhibition and binding of HSPDE4B2B by (R, R)-(+/-)-methyl 3-acetyl-4-[3-(cyclopentyloxy)-4-methoxyphenyl]-3-methyl-1-pyrrolidin ecarboxylate (1), a novel inhibitor of phosphodiesterase 4 (PDE 4), were investigated. Binding experiments demonstrated high-affinity binding of 1 to HSPDE4B2B with a stoichiometry of 1:1. Inhibition of PDE activity showed only a single transition with an observed Ki similar to the apparent Kd determined by the binding experiments. Deletional mutants of HSPDE4B2B, which have been shown to bind (R)-rolipram with low affinity, were shown to interact with 1 with high affinity, indistinguishable from the results obtained with the full-length enzyme. Bound 1 was completely displaced by (R)-rolipram, and the displacement showed a biphasic transition that resembles the biphasic inhibition of HSPDE4B2B by (R)-rolipram. Theoretical analysis of the two transitions exemplified in the interaction of (R)-rolipram with HSPDE4B2B indicated that the two isostates were nonexchangeable. Phosphorylation at serines 487 and 489 on HSPDE4B2B had no effect on the stoichiometry of binding, the affinity for binding, or the inhibition of the enzyme by 1. These data further illustrate the presence of two isostates in PDE 4 as shown previously for (R)-rolipram binding and inhibition. In contrast to (R)-rolipram, where only one of the two isostates of PDE 4 binds with high affinity, 1 is a potent, dual inhibitor of both of the isostates of PDE 4. Kinetic and thermodynamic models describing the interactions between the nonexchangeable isostates of PDE 4 and its ligands are discussed.     

Absence of metabolism of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) by flavin-containing monooxygenase (FMO)

The N-nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a potent lung carcinogen present in tobacco and tobacco smoke. Carbonyl reduction, alpha-carbon hydroxylation (activation) and N-oxidation of the pyridyl ring (detoxification) are the three main pathways of metabolism of NNK. In this study, metabolism of NNK was studied with lung and liver microsomes from F344 rats, Syrian golden hamsters and pigs and cloned flavin-containing monooxygenases (FMOs) from human and rabbit liver. Thermal inactivation at 45 degrees C for 2 min reduced FMO S-oxygenating activity but did not affect N-oxidation of NNK, leading to the conclusion that FMOs are not implicated in the detoxification of NNK. Detoxification of NNK was not increased by n-octylamine or by incubation at pH 8.4, supporting the conclusion that FMOs are not involved in the metabolism of NNK. SKF-525A (1 mM) significantly reduced N-oxidation and alpha-carbon hydroxylation, suggesting that these two pathways were catalyzed by cytochromes P450. Metabolism of NNK was lower with lung microsomes than with liver microsomes. Inhibition of metabolism of NNK by SKF-525A was also observed with rat lung microsomes, leading to the conclusion that cytochromes P450 are involved in pulmonary metabolism of NNK. Cloned FMOs did not metabolize NNK. In conclusion, cytochromes P450 rather than FMOs are involved in N-oxidation of NNK. The high capacity of hamster liver microsomes to activate NNK does not correlate with the resistance of this tissue to NNK-induced hepatocarcinogenesis.     

Pharmacodynamics of 2-(4-benzyl-piperidino)-1-(4-hydroxyphenyl)-1-propanol (Ifenprodil). (3) Effects on the autonomic, peripheral and central nervous systems

Effects of ifenprodil tartrate, a potent vasodilator, on the autonomic, peripheral and central nerve system were studied in experimental animals. In isolated vas deferens of guinea pigs, the contraction in response to noradrenaline and sympathetic nerve stimulation was competetively antagonized by ifenprodil 10(-7)--10(-5) M (pA2: 7.69 against noradrenaline). Ifenprodil (50 approximately 1,000 mug/kg i.v.) inhibited the contraction of cat nictitating membrane and dog urinary bladder induced by sympathetic nerve stimulation. Ifenprodil (250 approximately 1,000 mug/kg i.v.) lowered adrenaline-induced lethality (ED50: 360 mug/kg). The drug produced a hypermotility of guinea pig uterus, and showed a transient hypertonus of dog gut which was abolished by atropine. Ifenprodil (10 approximately 20 mg/kg i.v.) inhibited the propulsion of charcoal meal in mice. In Shay rats, more than 10 mg/kg i.m. of the drug inhibited the secretion of acid gastric juice and the ulceration. Ifenprodil showed a potent local anesthetic action in the guinea pig cornea and skin. The spontaneous EEG of rabbits showed a resting pattern (0.25 approximately 2 mg/kg i.v.) followed by an arousal pattern (5 approximately 10 mg/kg). Ifenprodil (20 approximately 100 mg/kg p.o.) potentiated a hypnosis induced by barbital, and potentiated pentylenetetrazol, strychnine and picrotoxin induced convulsion. The drug (20 and 100 mg/kg p.o.) lowered the body temperature of rats. From these results it is concluded that ifenprodil produces a blocking action of alpha-adrenoceptors in various smooth muscle preparations and a direct relaxation of the smooth muscle itself without affecting the motor and central nerve systems.