单取代色氨酸四苯基卟啉稀土配合物的合成与表征

单取代色氨酸四苯基卟啉稀土配合物的合成与表征倪春林王静秋秦子斌（湖北三峡师范学院化学系宜昌４４３０００）（武汉大学化学系武汉４３００７２）自从第一个镧系卟啉配合物问世以来，人们对其衍生物的合成和性质进行了广泛研究。到目前为止，有关取代四苯基卟啉与稀...     

单取代甘缬二肽四苯基卟啉稀土配合物的合成研究

首次合成了五种新的单取代甘缬二肽四苯基卟啉稀土配合物，即乙酰丙酮－５－（对甘缬二肽苯基）－１０，１５，２０－三苯基卟啉钐、铕、铒、镱和镥配合物，用元素分析、红外光谱、激光拉曼光谱、电子光谱和氢核磁共振谱进行了表征。     

二乙基二硫代氨基甲酸稀土配合物的合成及促进橡胶硫化性能研究

于空气中一步合成出二乙基二硫代氨基甲酸稀土 (镧、钕、铕和混合稀土 )共四种配合物 ,产率达 90 %以上 ,本文首次报道了该系列稀土配合物促进橡胶硫化性能和应用于胶鞋大底生产的配方试验 ,结果表明 ,除混合稀土配合物外 ,镧、钕、铕配合物均具有对橡胶硫化促进作用。选择镧配合物在胶鞋大底生产上试用 ,生产的胶鞋物理机械性能均达国家一级品标准。     

水杨醛氨基酸Schiff碱与硫酸钕配合物的研究

本文合成了未见文献报道的水杨醛缩 DL—亮氨酸 Schiff碱钕配合物和水杨醛缩 L—异亮氨酸 Schiff碱的钕配合物。通过元素分析、摩尔电导、红外光谱、紫外光谱、荧光光谱、差热—热重分析等手段对配合物的组成和性质进行了确定和表征 ,两种配合物的组成可能为 Nd2 (Sal- L ue) 2 (SO4) 2 、Nd3 (Sal- IL ue) 2 (SO4) 2 · 2 H2 O。     

聚(苯乙烯-丙烯酰胺)负载氯化钕配合物在4-乙烯吡啶聚合反应中的催化性能

本文对聚 (苯乙烯 -丙烯酰胺 ) (PSAM)负载氯化钕配合物催化剂催化 4-乙烯吡啶极性单体聚合反应进行了研究。考察了 Al/ Nd摩尔比、催化剂浓度、反应时间和温度对聚合的影响。结果表明 ,聚合物负载氯化钕配合物的催化性能高于同类小分子体系和稀土氯化物。聚合物负载氯化钕配合物催化活性与载体中功能基团(CONH2 )含量的多少及所形成的稀土钕配合物中钕含量的多少有关。当 PSAM· Nd Cl3 中的钕含量为 2 .7× 10 - 4mol/ g,钕含量与功能团含量摩尔比在 0 .2 5左右时 ,配合物的催化活性达到最佳值     

一系列功能性四苯基卟啉衍生物的合成及表征

以苯甲醛和吡咯为原料通过Adler缩合的方法合成了四苯基卟啉(TPP),以此为母体,采用Vilsmeier甲酰化反应合成了2-甲酰基-5,10,15,20-四苯基卟啉(FTPP),以此为中间体,通过Wittig反应合成了一系列四苯基卟啉衍生物.用傅里叶变换红外光谱、核磁共振氢谱、碳谱及MALDITOF质谱等手段对目标产物的结构进行了表征.并且初步研究了化合物L3的光学性质,其主要发射峰在650 nm,是纯正的红光材料.     

光度法二元稀土混合物中钕、钐的同时测定

本文研究了钕、钐与半二甲酚橙及氯化十六烷基吡啶配合物的吸收光谱和导数吸收光谱。发现钕、钐配合物的最大吸收波长均位于６０６ｎｍ，二者的吸光度具有良好的加合性。钕配合物的４ｆ电子跃迁峰在５８５ｎｍ有显著增强，用四阶导数光谱测定钕。基于此，发展了一个光度法同时测定钕、钐的新方法，对合成样进行分析，结果令人满意。     

Eu(bpy)2(NO3)3(H2O)2/Nafion修饰于金电极上的电化学发光性质研究

本文合成了铕-联吡啶的二元配合物Eu(bpy)2(NO3)3(H2O)2,用元素分析、红外及紫外光谱对配合物进行了表征.采用循环伏安法,研究了用Nafion将Eu(bpy)2(NO3)3(H2O)2修饰于金电极上的电化学发光行为.讨论了介质、pH对该体系电化学发光性质的影响,推测了Eu(bpy)2(NO3)3(H2O)2电化学发光的机理.结果表明:在没有共反应试剂存在的条件下,Eu(bpy)2(NO3)3(H2O)2在pH 8.0的硼砂缓冲溶液中可以产生较强的电化学发光,其发光体可能为Eu*(bpy)2(NO3)3(H2O)2.     

一种新型三足席夫碱稀土配合物的合成及与DNA作用方式的研究

合成了一种新型三足席夫碱和它的四种稀土配合物,通过元素分析、红外光谱、紫外光谱、差热-热重、核磁共振和摩尔电导率对配合物进行了表征,推测了配合物的可能结构。应用紫外可见光谱法和电化学方法对配合物与ct-DNA之间的相互作用进行了研究,结果表明,配合物与ct-DNA之间存在插入作用;配合物CV测试随扫描速度增加,其氧化峰电位Ep发生正移,氧化峰电流Ip随扫描速度的增加呈线性增加趋势,并且Ip与扫描速率平方根(v1/2)呈良好线性关系,表明配合物在GCE上的电化学氧化反应是一个受扩散步骤所控制的过程。     

全国第二届无机微量及痕量分析学术讨论会金银分析论文摘要选登

本文用分光光度法研究了meso-四(N-甲基-3-吡啶基)卟啉〔简称T(3-MPy)P〕与金(Ⅲ)的配合反应,制定了测定金(Ⅲ)的分光光度法,并对其反应动力学性质进行了初步探讨。T(3-MPy)P与Au(Ⅲ)形成1∶2配合物,表观摩尔吸光分数为3.24     

Change of karyoskeleton during mammalian spermatogenesis: expression pattern of nuclear lamin C2 and its regulation

The photophysical and photochemical properties of porphyrins were profoundly changed upon addition of rhodamine 123. The Soret band of the porphyrins shifted to higher wavelengths, the fluorescence yield of the porphyrins decreased with unaltered decay rates, and their triplet state was quenched. These observations indicate a strong interaction between porphyrins and rhodamine 123 and formation of 1:1 nonfluorescent complexes, of which the binding constants were determined. Illumination of a porphyrin in the presence of rhodamine 123 resulted in the formation of a porphyrin radical cation, which could be detected with ESR spectroscopy. Quenching of the triplet state of the porphyrins by rhodamine 123 resulted in a decreased singlet oxygen yield and a decrease of the photooxidation of histidine, methionine, tyrosine, and tryptophan. However, the oxidation of thiol compounds was increased and the stoichiometry of the reaction between cysteine and oxygen changed from 2 to 3.8 mol cysteine/ mol oxygen. These results show that the presence of rhodamine 123 converted the for porphyrins prevalent energy transfer (type II) reaction to an electron transfer (type I) reaction.     

Chromatographic analysis of photodynamically significant porphyrin dimers and trimers

Two porphyrin dimers, dihematoporphyrin dimer (DHD) and divinyl dimer (DVD), and two porphyrin trimers, dihematoporphyrin trimer (DHT) and divinyl trimer (DVT), have been analyzed utilizing isocratic ion-pair reversed-phase high-performance liquid chromatography. Results indicate that the vinyl porphyrins can be distinguished by three peaks appearing near 15, 38, and 42 min. The hematoporphyrin complexes are identified by the appearance of a peak located at 35 min. The DVT and DVD complexes present unique chromatographic markers at 28 and 15 min, respectively. Based on the location of these chromatographic markers, it was found that the Photofrin drug must contain the DVD and the DHT complexes, but does not contain the DVT complex. The purity of the DVT complex is compromised by the presence of DHD and DHT impurities.     

Measurement of the volume of a leg ulcer using a laser scanner

BACKGROUND AND AIMS: Uroporphyrin and protoporphyrin produce alterations on 5-aminolevulinic acid dehydratase and porphobilinogen deaminase, as a result of a direct effect of porphyrins on the protein structure. With the aim of assessing the possible protection from the porphyrins effect on the proteins, some chemicals and the enzyme substrates were assayed. METHODS: Enzymes were pre-incubated with the protecting agents (beta-mercaptoethanol, dithiotreitol, hydroxylamine, succinic anhydride) or the corresponding substrates (delta-aminolevulinic acid and porphobilinogen), and then exposed to the porphyrins. All experiments were performed in the enzyme solutions after removing the porphyrins. RESULTS: The presence of sulfhydryl reagents partially protected both the enzyme activities and the content of total SH and free amino groups, but they did not prevent the appearance of molecular aggregates in the electrophoresis. Similar results were obtained in the presence of the corresponding substrates. Nucleophilic addition of hydroxylamine to the aromatic amino acids on the enzymes and blockage of their free amino groups did not prevent the direct effect of porphyrins, but these agents protected the enzyme activities from the photodynamic action of the tetrapyrroles, and also prevented the formation of molecular aggregates. However, an increased amount of free amino groups was observed, probably due to protein fragmentation. CONCLUSIONS: Porphyrins mainly affected the SH groups at or near the active site of the enzymes. Most of the free amino groups on the treated enzymes were involved in the formation of cross-links among the protein molecules. Protein fragmentation induced by porphyrins under UV light, and the consequent increased amount of free amino groups, were observed.     

Thermal Stability and Luminescence Properties of Eu^3＋ and Tb^3＋ Complexes with a Silica Matrix by Sol-Gel Method

Ternary complexes of europium and terbium with benzoic acid and 1, 10-phenanthroline [RE(BA)3phen] (BA=benzoate phen=1,10-phenanthroline) were introduced into a silica matrix by sol-gel method. The thermal stability and luminescence behavior of the complexes in silica gels were studied in comparison with the corresponding solid-state complexes by thermal decomposition, excitation and emission spectra. The thermal stability of the complexes is enhanced in silica gel matrix and the luminescence remaines unchanged.     

5-Aminolevulinic acid induced endogenous porphyrin fluorescence in 9L and C6 brain tumours and in the normal rat brain

A new approach in photodynamic therapy is the use of endogenous porphyrins for sensitisation of tumours to light. The induction of endogenous porphyrins after intravenous injection of 5-aminolevulinic acid (ALA, 200 mg kg-1) was studied in 23 rats, bearing intracranial 9L or C6 tumours. After 0, 2, 4, 6, 8, and 22 hours the rats were sacrificed and the fluorescence distribution of endogenous porphyrins was studied in brain tissue sections with a standard fluorescence microscope and a confocal laser scanning microscope. The role of blood-brain barrier disruption on porphyrin production was studied in 2 rats with a cryo-lesion of the cortex. Additionally, 9L and C6 tumour cell cultures were incubated with ALA for 8 hours in vitro. Fluorescence was measured with a fluorescence spectrophotometer in cell cultures and in the brain sections. Porphyrins were detected in vitro in the tumour cells from 2 hours onwards and ex vivo in the tumour sections mainly from 2 to 8 hours, by 22 hours porphyrin fluorescence had almost disappeared. The contralateral brain showed low fluorescence levels between 2 and 6 hours after ALA administration. At the site of the cryo-lesions low fluorescence was measured 6 hours after ALA administration. The 9L tumours fluoresced homogeneously, with a sharp demarcation towards normal brain tissue. Fluorescence in the C6 tumours was patchy, with a poorly fluorescing edge. In both tumour models fluorescence was also detected in brain surrounding the tumour and sometimes in contralateral white matter and ventricle ependyma and pia mater. The slight increase of porphyrin fluorescence in the normal brain of tumour bearing rats, compared to the absence of this in rats without a tumour, was attributed to transport by bulk flow of porphyrins made in the tumours, and possibly also of circulating porphyrins or ALA leaking from the tumour vessels.     

A study of an automated porphyria diagnosis system using urinary porphyrin profile analysis

Porphyrins are essential substances for the biosynthesis of heme. Porphyria results from a disorder in the metabolism of porphyrin. Patients suffering from Porphyria exhibit changes in their porphyrin profiles as measured in excretia and organs. A highly sensitive and simple analytical method using high-performance liquid chromatography (HPLC) for all porphyrin metabolites in urine was established. This method is able to separate porphyrins such as uroporphyrin, carboxylic acid porphyrins of hepta-, hexa-, penta-, and coproporphyrin isomers of I and III in a sample of human urine. In this study, the combination of HPLC with a computer system for automated porphyria diagnosis was investigated. The profile of all urinary porphyrins from patients with various Porphyria were measured by HPLC and diagnosed by the computer diagnostic system. This system enabled the estimation of 5 types of porphyrias with a high accuracy of diagnosis.     

Porphyrin-induced protein structural alterations of heme enzymes

Some alterations in the protein structure of delta-aminolevulinic acid dehydratase (ALA-D) and porphobilinogen deaminase (PBG-D) induced by uroporphyrin (URO) and prototoporphyrin (PROTO) have been observed previously. To obtain further evidence of these phenomena, the absorption and fluorescence spectra of ALA-D and PBG-D and the total protein content of sulfhydryl and free amino groups were analyzed after exposure of the enzymes to URO I and PROTO IX, ALA-D and PBG-D were partially purified from bovine liver and exposed to URO I or PROTO IX, both in the dark and under UV light. All experiments were performed in the enzyme solutions after removing the porphyrins. Absorbance spectra changes in the region of 220-300 nm were registered, indicating the interaction of the porphyrins with the molecular structure of the enzymes. The main changes in the fluorescence spectra were observed in the spectral region of 555 nm, and only slight modifications in the spectral region of 340-360 nm; moreover, alterations were stronger upon UV irradiation and in the presence of URO I when compared with darkness and PROTO IX. Variations in total SH groups would suggest the formation of disulfur bridges induced by URO I and the rupture of some S-S groups induced by PROTO IX. The effect of porphyrins on free amino groups would reflect a combination of cross-linking and fragmentation of proteins. Structural changes were observed when the enzymes were exposed to the porphyrin both in the dark or under UV light; however, they were stronger in the latter condition. These results suggest that porphyrins per se could act directly on the protein structure and that this action would be enhanced upon UV irradiation.     

Luminescence of Terbium Complexes Incorporated into Silica Matrix

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Activation of JNK and p38 but not ERK MAP kinases in human skin cells by 5-aminolevulinate-photodynamic therapy

5-Aminolevulinate (ALA) photodynamic therapy (PDT) is being used clinically for the treatment of skin cancers. ALA is applied as a precursor of porphyrins serving as endogenous photosensitizers. Irradiation of HaCaT cells preincubated with 1 mM ALA for 24 h with red light of 570-750 nm at a dose of 4.5 J/cm2 leads to a 6-fold elevation of cellular c-Jun N-terminal kinase activity; phosphorylation of p38 mitogen-activated protein kinase (MAPK) is enhanced to a similar extent. In contrast, neither activation nor increased phosphorylation of the extracellular stimulus-regulated kinase MAPKs is detected. p38 is also phosphorylated by ALA-PDT in the human melanoma cell lines Bro and SkMel-23, applying doses that lead to 80-95% cell death after 24 h. Hence, the effects of ALA-PDT on MAPKs are similar to stresses like UV irradiation or exposure to hydrogen peroxide with respect to activation of JNK and p38 MAPKs. They are different, however, in that extracellular stimulus-regulated kinase activity is not raised by ALA-PDT. Of the 830 pmol porphyrins/mg protein that were present at 24 h in HaCaT cells, 99 pmol/mg were intracellular. When extracellular porphyrins had been removed by washing, p38 responses were retained. Thus, intracellular porphyrins synthesized from ALA are sufficient to elicit activation of p38 on photosensitization.     

Effects of cationic porphyrins as G-quadruplex interactive agents in human tumor cells

A series of cationic porphyrins has been identified as G-quadruplex interactive agents (QIAs) that stabilize telomeric G-quadruplex DNA and thereby inhibit human telomerase; 50% inhibition of telomerase activity was achieved in HeLa cell-free extract at porphyrin concentrations in the range < or = 50 microM. Cytotoxicity of the porphyrins in vitro was assessed in normal human cells (fibroblast and breast) and human tumor cells representing models selected for high telomerase activity and short telomeres (breast carcinoma, prostate, and lymphoma). In general, the cytotoxicity (EC50, effective concentration for 50% inhibition of cell proliferation) against normal and tumor cells was > 50 microM. The porphyrins were readily absorbed into tumor cell nuclei in culture. Inhibition of telomerase activity in MCF7 cells by subcytotoxic concentrations of TMPyP4 showed time and concentration dependence at 1-100 microM TMPyP4 over 15 days in culture (10 population doubling times). The inhibition of telomerase activity was paralleled by a cell growth arrest in G2-M. These results suggest that relevant biological effects of porphyrins can be achieved at concentrations that do not have general cytotoxic effects on cells. Moreover, the data support the concept that a rational, structure-based approach is possible to design novel telomere-interactive agents with application to a selective and specific anticancer therapy.