胆固醇分子印迹聚合物的制备及其选择性吸附

随着人们生活水平的逐步提高,因人体内胆固醇过高所产生的疾病呈逐年增加的趋势.近年来的研究表明,胆固醇分子印迹聚合物对胆固醇具有良好的选择性吸附能力.将胆固醇分子印迹聚合物作为胆固醇的识别剂,提取食品中的胆固醇和治疔胆固醇有关的疾病,展现出了良好的应用前景.本文分别从胆固醇分子印迹聚合物的制备方法、识别机理、提高选择性识别途径以及新的印迹方法等方面进行了综述.     

一维Ag纳米粒子修饰电极的胆固醇传感器

随着胆固醇的加入,一维多孔Ag纳料材料修饰GCE对胆固醇的电流响应逐渐增加峰电位为0.36V,略向正电位方向移动.随着胆固醇浓度的增加电流响应逐渐增加说明用一维多孔Ag纳料位子修饰GCE基于胆固醇的氧化可以构建无酶胆固醇传感器.     

溶胶凝胶固定化酶流动注射化学发光法测定人体血清中的胆固醇

采用溶胶凝胶技术分别固定了胆固醇脂酶和胆固醇氧化酶,制成固定化酶柱;人体血清中胆固醇脂在胆固醇脂酶的催化作用下生成胆固醇,胆固醇在胆固醇氧化酶的催化作用下被氧化产生H2O2,将其与鲁米诺发生耦合的化学发光反应,在模拟酶血红蛋白的催化作用下产生较强的化学发光。结合流动注射技术,建立了溶胶凝胶固定化酶流动注射化学发光法测定胆固醇的新方法。实验发现,发光强度与胆固醇的浓度在一定范围内呈良好的线性关系,总胆固醇的线性范围为1.01×10-6～2.02×10-4mol/L(r=0.9975);检出限为7.5×10-7mol/L;游离胆固醇的线性范围为5.0×10-8～2.18×10-5mol/L(r=0.9991);检出限为5.0×10-9mol/L。用生化分析仪(东芝TBA-120FR)与本方法进行对照,两种方法无显著性差异。本方法已应用于临床血清样品中胆固醇的检测。     

光导纤维胆固醇生物传感器的研究

将胆固醇酯酶、胆固醇氧化酶和辣根过氧化物酶通过戊二醛交联反应,固定在牛血清蛋白上,制成光纤胆固醇生物传感器的传感膜.此传感器偶合了胆固醇酯水解、胆固醇的氧化和鲁米诺同过氧化氢的化学发光等3种酶催化反应,通过光纤输出的化学发光信号进行检测.测定总胆固醇和自由胆固醇的线性范围均为0.5～20μg/mL,检测下限为0.1μg/mL,响应时间为2min,寿命在2个月以上,适用于血清中总胆固醇和游离胆固醇的测定.     

血清中非胆固醇类固醇检测方法研究进展

人体血清中除含有胆固醇外,还含有微量的角鲨烯和非胆固醇类固醇.近年的研究发现:血清中的角鲨烯和胆固醇前体固醇可以反映机体的内源性胆固醇合成效率,而植物固醇可反映机体的外源性胆固醇吸收效率~([1]).胆固醇前体固醇和植物固醇是一类以环戊烷全氢菲为骨架的醇类化合物.在某些家族性血脂代谢异常的患者血清中,非胆固醇类固醇的含量会明显偏高~([2]).因此,分析固醇类物质含量与血脂代谢的关系,就显得尤为重要.     

钒的生理作用及其与健康的关系

一、钒的生理作用 （1）抑制胆固醇的合成并加速其分解,许多研究资料证明,钒可抑制内源性胆固醇的合成,特别是抑制肝内胆固醇的合成并可加速其分解。钒作业工人血清胆固醇含量明显低于对照。实验显示,钒可清除沉积在主动脉壁上的胆固醇。但钒含量过高时促进动脉粥样硬化的发生。     

新型胆固醇侧部衍生物的合成研究

由于胆固醇和氢化胆固醇均是较好的液晶基元,引起了广泛的关注和研究.在胆固醇分子中,C(3)上有一个羟基,C(5)=C(6)之间含有一个双键,双键的存在使得胆固醇分子具有较好的刚性,因此大量的研究工作都集中在利用C(3)上的羟基制备胆固醇衍生物.但是C(5)=C(6)之间的双键也是可以利用的官能团,可以在胆固醇分子的双键部位引入适当的官能团,而得到一些新的衍生物,因此,对胆固醇C(5)=C(6)位双键的化学修饰就成了本研究的重点.首次探讨了将6-溴己酸或丙烯酸通过双键环氧化,然后开环的方法连到胆固醇侧部双键位置,为合成新型的含胆固醇衍生物的聚合物研究奠定了基础.     

膳食纤维降血脂作用及其机制的研究进展

综述了近年膳食纤维降脂作用及其机制的研究进展.膳食纤维能使血清中胆固醇、甘油三酯、低密度脂蛋白水平降低,高密度脂蛋白水平升高.其主要机制为通过减少膳食中胆固醇的吸收、影响机体中胆固醇的代谢、促进胆固醇的排泄等降低血浆中胆固醇水平;通过增加食物在肠道内的过渡时间、延缓胃排空、减缓或降低脂肪的吸收等机制降低血浆中甘油三酯水...     

应用对映异构胆固醇探测离子通道

明尼苏达大学化学助教授Scoff D.Rychnovsky以及Daniel E.Mickus和David G.leviff首次以单异构体形式制备成功对映异构胆固醇(胆固醇的镜像),用来探测胆固醇在细胞膜离子     

基于β-环糊精主客体识别的胆固醇吸附剂的研究进展

胆固醇是人体内必不可少的一种脂质分子,在人体的代谢过程中发挥着至关重要的作用。机体内胆固醇淤积往往与动脉粥样硬化、C型尼曼匹克氏症等疾病的发生密切相关,但现今药物的副作用以及禁忌症给临床治疗带来了诸多不便。β-环糊精是一种能够识别胆固醇的天然大环分子,其与胆固醇之间的主客体相互识别作用可用于胆固醇的特异性吸附与清除。在本综述中,我们总结了近年来基于β-环糊精主客体识别作用的胆固醇吸附剂的制备方法、设计原理及研究现状,展现了β-环糊精作为功能吸附基团在治疗高胆固醇相关疾病应用上的巨大潜力。     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

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.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

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.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.