葡萄糖与杂环化合物在甲酰胺中的焓相互作用参数

由于糖具有特殊的生物和生理性质 ,在工业生产中已有广泛应用 ,故其溶液热力学性质已成为人们感兴趣的研究课题之一 .糖在水溶液中的热力学性质已见文献报道 [1] ,但在非水体系中的有关数据则较少报道 .研究表明 ,溶剂介质的变化对溶质的溶剂化状态和溶质间相互作用的影响较大 ,选用酰胺为溶剂可以获得模拟蛋白质环境条件下的溶质 -溶剂、溶质 -溶质间相互作用的信息 [2～ 4] .本文利用微量量热法测得了葡萄糖在杂环化合物与甲酰胺的混合溶剂中的溶解焓 .如果把杂环化合物作为 x,葡萄糖作为 y,按照 Mc Millan- Mayer[5 ] 理论 ,1 mol葡萄…     

甘氨酸从水到有机物水溶液的迁移焓研究

蛋白质是各种生物形态结构和生命活动所依赖的物质基础,在水溶液中蛋白质天然结构的稳定性归结于氨基酸残基之间以及与溶液中其它组分的相互作用．天然环境中存在的众多物质对蛋白质的溶解度、变性行为和解缔等都有很大的影响．为深入了解蛋白质折叠与解折叠过程中的物理化学现象,以氨基酸、肽、酰胺及其衍生物作为蛋白质模型分子的热力学研究引起了广泛重视．     

芳香低聚酰胺类α-螺旋模拟物研究进展

α-螺旋模拟物是一类重要的小分子蛋白质相互作用抑制剂。芳香低聚酰胺类小分子α-螺旋模拟物具有许多优点,近年来取得了较快的发展。综述了近几年来芳香低聚酰胺类α-螺旋模拟物的最新进展。     

肌醇在纯水和卤化钠水溶液中稀释过程的热力学性质

应用微量热法测定了298.15 K时肌醇在纯水和卤化钠水溶液中的稀释焓, 根据McMillan-Mayer理论, 计算了肌醇在溶液中的二到四阶焓相互作用系数. 结果表明, 肌醇在卤化钠溶液中的焓对相互作用系数h2均为负值, 并且随着卤素阴离子半径的增大, h2的绝对值呈增大趋势.     

肌醇在氯化钠水溶液中的稀释焓和焓对相互作用

应用微量热法测定了298.15K时肌醇在纯水和氯化钠水溶液中的稀释焓,根据McMillan-Mayer理论计算了肌醇在不同浓度的氯化钠溶液中的2到4阶焓相互作用系数.结果表明,肌醇在氯化钠溶液中的焓对相互作用系数h2均为负值,并且随着氯化钠浓度的增大,h2的值呈增大趋势.根据溶质-溶质相互作用和溶质-溶剂相互作用对焓对相互作用系数的变化趋势进行了解释.     

木糖醇在纯水和碱金属卤化物水溶液中的稀释焓

应用等温流动微量热法测定了298.15 K时木糖醇在纯水和碱金属卤化物水溶液中的稀释焓, 根据McMillan- Mayer理论计算了木糖醇在溶液中的二到四阶焓相互作用系数. 结果表明, 木糖醇在碱金属卤盐溶液中的焓对相互作用系数h₂均为正值, h₂值随着碱金属阳离子或卤素阴离子半径的增大皆依次增大. 根据木糖醇参与的溶质-溶质, 溶质-溶剂等弱相互作用, 对该种多元醇在碱金属卤盐水溶液中的焓相互作用系数的变化进行了解释.     

甘氨酸从水到酰胺衍生物水溶液中的迁移焓

用RD496-Ⅱ型微量热量计测定了298.15 K甘氨酸在N-甲基甲酰胺（NMF）,N, N-二甲基甲酰胺（DMF）,N-甲基乙酰胺（NMA）,N, N-二甲基乙酰胺（DMA）水溶液中的溶解焓,计算了甘氨酸从水到四种酰胺衍生物水溶液中的迁移焓（ΔtrH）。根据结构水合作用模型讨论了酰胺的结构对甘氨酸迁移焓的影响。实验结果表明：甘氨酸在酰胺衍生物水溶液中的迁移焓均为正值,并且随着溶液浓度增大而增大。比较甘氨酸在甲酰胺（FA）和乙酰胺（AD）水溶液中的迁移焓,发现在不同酰胺水溶液中迁移焓大小为：DMA>NMA>DMF>NMF>AD>FA。甘氨酸与甲酰胺之间以亲水-亲水相互作用为主,与其它酰胺之间以亲水-疏水作用为主。     

蛋白质相互作用预测、设计与调控

蛋白质相互作用是生命活动在分子水平上的基本事件. 蛋白质相互作用的三维图像可以给出关键生命活动过程的分子细节. 了解蛋白质相互作用的原理有助于揭示生命活动的机制, 并在此基础上开展有重要价值的蛋白质设计. 本文对于蛋白质相互作用预测、设计和调控研究的近期进展进行了总结归纳, 介绍了作者实验室在相关领域的研究进展, 并对今后的研究方向进行了展望. 主要包括: (1) 蛋白质相互作用网络、蛋白质相互作用机制和蛋白质复合物结构计算分析; (2) 基于序列、结合位点以及复合物结构的蛋白质相互作用预测; (3)蛋白质相互作用设计方法; (4) 利用化学分子调控蛋白质相互作用的方法; (5) 针对蛋白质相互作用的蛋白质药物设计方法.     

D-甘露醇与D-山梨醇在纯水和卤化钠水溶液中的稀释焓

应用等温流动微量热技术测定了298.15 K下D-甘露醇和D-山梨醇在纯水和卤化钠水溶液中的稀释焓,利用M cM illan理论计算了D-甘露醇和D-山梨醇在纯水和卤化钠水溶液中焓相互作用系数.结果表明,D-甘露醇和D-山梨醇在纯水和卤化钠水溶液中的二阶焓相互作用系数均为正值,并随着卤离子半径的变化而相应变化;且同种溶剂中,D-甘露醇的二阶焓相互作用系数要大于D-山梨醇的.结合两分子结构的差异,通过溶质-溶质相互作用和溶剂-溶质相互作用对这一结果进行了讨论.     

小分子α-螺旋模拟物

本文综述了近年来小分子α-螺旋模拟物的研究进展,介绍了α-螺旋结构在蛋白质相互作用中的重要性以及小分子α-螺旋模拟物在药物化学领域的应用。概括了联苯结构、酰胺结构、哒嗪结构及其他杂环结构小分子α-螺旋模拟物的最新进展,并介绍了小分子α-螺旋模拟物在蛋白质相互作用抑制剂方面的应用。总结了目前已有的小分子α-螺旋模拟物存在的一些不足之处,并对今后该研究领域的发展方向进行了展望。     

Enthalpic Interaction Coefficients of Formamide in Aqueous Methanol and Ethanol Solutions at 298.15 K

The dilution enthalpies of formamide in aqueous methanol and ethanol solutions have been determined using a CSC-4400 isothermal calorimeter at 298.15 K. The homogeneous solution enthalpic interaction coefficients have been calculated over a range of alcohol concentrations according to the excess enthalpy concept. The results show that the enthalpic pair interaction coefficients h ₂ of formamide are negative in aqueous alcohol solutions and pass through a minimum in mixed solvents, whereas the h ₂ coefficients of formamide in aqueous ethanol solutions are more negative than those in aqueous methanol solutions. The results are discussed in terms of solute-solute and solute-solvent interactions.     

Solvation of amides of carboxylic acids in aqueous solutions of ethylene glycol

Enthalpies of solution of amides of formic, acetic, and propionic acids with different degrees of N-substitution in aqueous solutions of ethylene glycol were measured at 298.15 K. The concentration of ethylene glycol did not exceed 4 mol kg^–1. The reasons for increasing endothermic values of the enthalpies characterizing the amide transfer from water to a mixed aqueous-organic solvent on going from primary to tertiary amides and from formamides to the corresponding acetamides are discussed. The enthalpic coefficients of pair interactions between amides and ethylene glycol in water were calculated. The endothermicity of the interaction of the alkyl groups of the amide molecules with ethylene glycol results in positive values of the coefficients. The coefficient values increase with the enhancement of the hydrophobic properties of hydrophilic non-electrolytes (urea, formamide, ethylene glycol) due to an increase in the contribution of the hydrophobic component and a decrease in the contribution from the interaction of the polar groups of amides to the total interaction.     

甲酰胺与肌醇在氯化钠水溶液中的焓相互作用

应用等温流动微量热法测定298.15 K时甲酰胺与肌醇分子在不同浓度氯化钠水溶液中的混合过程焓变及其稀释焓, 根据McMillan-Mayer理论关联得到各级异系焓相互作用系数(h_xy, h_xxy及h_xyy). 结果表明, 甲酰胺与肌醇分子在氯化钠水溶液中的异系焓对相互作用系数h_xy均为负值, 并且随着氯化钠浓度的增加, h_xy的绝对值逐渐减小.     

N,N-二甲基甲酰胺在不同浓度氯化钠水溶液中的稀释过程热力学

应用等温流动微量热法测定了298.15 K时N,N-二甲基甲酰胺(DMF)在纯水及不同浓度氯化钠水溶液中的稀释焓, 根据McMillan-Mayer理论计算得到各级同系焓相互作用系数. 结果表明, DMF在纯水及氯化钠水溶液中的焓对相互作用系数h2均为正值, 并且随着氯化钠浓度的增加, h2的值逐渐增大. 根据溶质-溶质相互作用和溶质-溶剂相互作用对结果进行了解释.     

Calorimetric and Volumetric Studies of the Interactions of Propionamide in Aqueous Alkan-1-ol Solutions at 298.15 K

Enthalpies of solution and apparent molar volumes have been determined for propionamide in aqueous methanol, ethanol and propanol solutions at 298.15 K using a C-80 microcalorimeter and a DMA60/602 vibrating-tube digital densimeter. The enthalpic and volumetric interaction coefficients have been calculated. Using the present results along with results from previous studies for formamide, the pair-interaction coefficients are discussed from the perspective of dipole-dipole and structural interactions. In addition, the triplet interaction coefficients are interpreted by using the solvent-separated association mechanism.     

Heterotactic Enthalpic Interactions of L-Arginine with 2,2,2-Trifluoroethanol in Aqueous Solutions at 298.15, 303.15 and 310.15 K

The enthalpies of mixing of L-arginine with 2,2,2-trifluoroethanol and their respective enthalpies of dilution in aqueous solutions at 298.15, 303.15 and 310.15 K were determined as a function of the mole fraction by flow microcalorimetric measurement. These experimental results were analyzed to obtain heterotactic enthalpic interaction coefficients(hxy, hxxy, hxyy) according to the McMillan-Mayer theory. The hxy coefficients between L-arginine molecule studied and 2,2,2-trifluoroethanol molecule in aqueous...     

Thermodynamic parameters of intermolecular interaction in strongly associated solvents and their mixtures with dimethylformamide

The specific and nonspecific constituents of the total energy of intermolecular interasction in ethylene glycol, diethylene glycol, and formamide were determined for the range 288.15–323.15 K using a simulation approach. Diethylene glycol, like formamide and ethylene glycol, forms networks of hydrogen bonds. In ethylene glycol and formamide, the hydrogen bonds make a predominant contribution to the total interaction energy. The specific and nonspecific contributions in mixtures of the above solvents with dimethyl-formamide were calculated, and the results were discussed in combination with the data for aqueous dimethyl-formamide solutions.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 11, 2004, pp. 1789–1796.Original Russian Text Copyright © 2004 by Zaichikov, KrestyaninovThis revised version was published online in April 2005 with a corrected cover date.     

A study of solute-solute interactions of amides dissolved in N-methylformamide by enthalpic interaction coefficients

Enthalpies of dilution of formamide, acetamide, propionamide, butyramide and hexanamide, dissolved in N-methylformamide have been measured calorimetrically at 25°C. From the results McMillan-Mayer coefficient related enthalpic pair and triplet interaction coefficients have been calculated. Except for those of formamide, all pair coefficients are negative, whereas the triplet terms are positive. The values in the protic solvent N-methylformamide presented in this paper together with those published before are compared with results for corresponding solutes dissolved in the aprotic solvent N,N-dimethylformamide. A discussion of the dependence of the interaction coefficients on the applied concentration scale is given and conversion factors are presented. The influence of hydrogen bonding, of substituent effects on this hydrogen bonding, and of polarophobic interaction is discussed. The latter is comparable in N,N-dimethyl-and N-methylformamide. The enthalpic pair interaction coefficients have been correlated with the Excess Group Additivity approach.To whom correspondence should be addressed.     

Enthalpies of dilution and homotactic enthalpic interaction coefficients of THF and 1,4-dioxane at 298.15 k

Enthalpies of dilution at 298.15 K of aqueous solutions of THF and 1,4-dioxane have been determined using flow microcalorimetry. The results obtained were used to determine the homotactic enthalpic interaction coefficients that characterize pair interactions of THF and 1,4-dioxane in aqueous solution. These are briefly discussed from the point of view of intermolecular interaction between the hydrated solute species.