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1.
一种新型结构的金属硫蛋白Pb-MT   总被引:2,自引:0,他引:2  
金属硫蛋白(metalothioneins,简称MTs)是一大类富含巯基的小分子蛋白质(分子量<9000),具有很强的金属结合能力,哺乳动物MT每分子可结合7个二价金属离子或12个一价金属离子.MT的结构一直是科学家关注的热点,其中哺乳动物Cd7-M...  相似文献   

2.
金属硫蛋白(metallothionein,简称MT)是一类低分子量、富含半胱氨酸的金属结合蛋白,具有调节体内微量金属元素(Zn、Cu等)代谢、重金属解毒和清除自由基等多种生物学功能[1].MT与金属离子的络合作用是发挥其功能的物质基础,哺乳动物MT每分子含20个半胱氨酸巯基,可结合7个二价金属离子或12个一价金属离子;通常,各种金属离子的结合能力与典型的硫酸盐型络合物的顺序一致,即 Zn(Ⅱ)< Pb(Ⅱ)< Cd(Ⅱ)< Cu(Ⅰ), Hg(Ⅰ), Hg(Ⅱ), Bi(Ⅲ)[2].哺乳动物Cd7-…  相似文献   

3.
三种金属硫蛋白动力学稳定性的理论研究   总被引:1,自引:1,他引:0  
对三类金属硫蛋白(大鼠金属硫蛋白亚型Ⅱ,兔肝金属硫蛋白亚型Ⅰ和兔肝金属硫蛋白亚型Ⅱ)的单体和二聚体进行了水溶液条件下的分子动力学模拟。其中大鼠金属硫蛋白亚型Ⅱ的结构直接来自于晶体数据,兔肝金属硫蛋白亚型Ⅰ和Ⅱ的结构则通过同源蛋白模型搭建。动力学模拟的结果显示,这三种单体在水溶液中都具有相当大的柔性,柔性主要来源于柔性区的氨基酸残基。三类金属硫蛋白单体的动力学模拟均表明α结构域的动力学稳定性都要优于  相似文献   

4.
金属硫蛋白对铅的细胞毒性和免疫毒性的保护作用   总被引:4,自引:0,他引:4  
金属硫蛋白(MT)是一类低分子量富含巯基的非酶蛋白,其结构特殊。MT具有重金属解毒作用和对生物体所必需的微量元素储存、运输、调节作用,还具有增强机体应激能力,拮抗电离辐射,清除自由基等重要生物学功能。本文主要论证MT与重金属铅对机体的细胞毒性和免疫毒性的保护作用。  相似文献   

5.
研究了Co(Ⅱ)和金属硫蛋白反应的动力学,发现反应分三段进行,由此得到了不同条件下各段对应的假一级反应速率常数。假设金属硫蛋白中每个金属结合20/7个SH基团,用盐酸滴定CoTh(thioncin)和Co7Th,根据它们的紫外光谱特征波长处吸收值降至50%时的PH,分别又得到它们的表观平均稳定常数。  相似文献   

6.
Rm.M(dmit)2型有机金属配合物的合成与表征   总被引:5,自引:0,他引:5  
李洪启  宋燕西 《合成化学》1997,5(2):165-167
合成了2个系列9种新的季铵.二(在,3-一硫杂环戊烯-2-硫酮-4,5-二巯基)金属(缩写为Rm.M(dmit)2)型有机金属配合物,用元素分析,ICP和^1HNMR等对它们的结构进行了表征,并讨论了光谱特征。  相似文献   

7.
(Et4N)m.M(dmit)2型配合物的合成及其红外光谱   总被引:1,自引:0,他引:1  
(Et_4N)_m·M(dmit)_2型配合物的合成及其红外光谱李洪启,王爱勤,宋燕西,谭干祖,姚钟麒,俞贤达(中国科学院兰州化学物理研究所兰州730000)关键词二(二硫杂环戊烯硫酮二巯基)金属,配合物,合成,红外光谱由二(1,3-二硫杂环戊烯-2-...  相似文献   

8.
许主国  许鹏飞 《合成化学》1996,4(2):137-140
合成了新配体1-N-(苯并咪唑-1-乙酰基)-4-苯基-3-氨基硫脲(BPMS),将其与Mn(Ⅱ),Co(Ⅱ),Ni(Ⅱ),Cu(Ⅱ),Cd(Ⅱ),Zn(Ⅱ),UO2(Ⅱ)等金属的醋酸盐反应,合成了7个新配合物,所有化合物均经元素分析,IRHNMR和热重分析等表征,红外光谱表明,配体以四齿方式通过烯醇式羰基氧还子,烯醇式硫羰基硫原子以及C=N^1和C=N^2的氮原子与金属配位。  相似文献   

9.
兔金属硫蛋白的分离与纯化   总被引:1,自引:0,他引:1  
兔皮下注射CdCl2诱导金属硫蛋白(Metallothionein,简称MT),取肝脏匀浆,用乙醇─氯仿混合液萃取后经SephdexG-50柱分离,得到混合型MT.进一步用纤维素弱碱性阴离子交换树脂进行拆分,并在SephadexG-25柱上脱盐,得到MT-1和MT-2两种亚型.经氨基酸组咸、凝胶电泳及HPLC柱层析等分析表明,所得的两种亚型具有高度的均一性.  相似文献   

10.
合成了新配体1-N-(苯并咪唑-1-乙酰基)-4-苯基-3-氨基硫脲(BPMS),将其与Mn(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)、Cu(Ⅱ)、Cd(Ⅱ)、Zn(Ⅱ)、UO2(Ⅱ)等金属的醋酸盐反应,合成了7个新配合物。所有化合物均经元素分析、IR、1HNMR和热重分析等表征。红外光谱表明,配体以四齿方式通过烯醇式羰基氧原子、烯醇式硫羰基硫原子以及C=N1和C=N2的氮原子与金属配位  相似文献   

11.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

12.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.  相似文献   

13.
The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.  相似文献   

14.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.  相似文献   

15.
An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.  相似文献   

16.
17.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

18.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

19.
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.  相似文献   

20.
Quercetin, the polyphenolic compound, which has the highest daily intake, is well known for its protective effects against aging diseases and has received a lot of attention for this reason. Both quercetin 3-O-β-d-glucuronide and quercetin 3′-O-β-d-glucuronide are human metabolites, which, together with their regioisomers, are required for biological as well as physical chemistry studies. We present here a novel synthetic route based on the sequential and selective protections of the hydroxyl functions of quercetin allowing selective glycosylation, followed by TEMPO-mediated oxidation to the glucuronide. This methodology enabled us to synthesize the five O-β-d-glucosides and four O-β-d-glucuronides of quercetin, including the major human metabolite, quercetin 3-O-β-d-glucuronide.  相似文献   

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