跨尺度方法研究聚合物载药胶束的定量构性关系

以两亲性聚合物自组装载药胶束为案例, 基于宏观到微观的跨尺度方法研究化学产品的定量构性关系(QSPR), 提出嵌段单元自相关方法计算表征两亲性聚合物结构的描述符, 结合遗传函数算法和多元线性回归建立了不同药物/聚合物配比下聚合物胶束载药量的QSPR预测模型, 经内部验证(R²>0.854, Q_loo-cv²>0.651, RMSE<0.089)、Y-随机化检验和外部验证(Q_ext²>0.629), 以及应用域定义分析评估了模型的可靠性、稳定性和预测能力。通过对描述符的分析和载药机制解释, 很好地阐释了聚合物嵌段单元和聚合物拓扑结构对胶束载药量的影响。QSPR模型的建立将指导新聚合物及其载药胶束体系的设计, 并预测其载药能力, 这种跨尺度研究方法有望促进复杂结构化产品的设计和开发。     

Computational modeling of in vitro biological responses on polymethacrylate surfaces

The objective of this research was to examine the capabilities of QSPR (Quantitative Structure Property Relationship) modeling to predict specific biological responses (fibrinogen adsorption, cell attachment and cell proliferation index) on thin films of different polymethacrylates. Using 33 commercially available monomers it is theoretically possible to construct a library of over 40,000 distinct polymer compositions. A subset of these polymers were synthesized and solvent cast surfaces were prepared in 96 well plates for the measurement of fibrinogen adsorption. NIH 3T3 cell attachment and proliferation indices were measured on spin coated thin films of these polymers. Based on the experimental results of these polymers, separate models were built for homo-, co-, and terpolymers in the library with good correlation between experiment and predicted values. The ability to predict biological responses by simple QSPR models for large numbers of polymers has important implications in designing biomaterials for specific biological or medical applications.     

多氯联苯热力学性质的构效关系

通过计算二噁英类化合物多氯联苯（PCBs）217种分子的定位指数和基团对应指数,以这些分子的热力学性质的文献值为建模样本,运用多元线性回归方法建立了多氯联苯的标准熵（S0）、标准焓（H0）、标准自由能（G0）、分子总能量（ET）、热能校正值（Eth）、零点振动能（Ezpv）及恒容热容（Cv0）等热力学性质的定量结构-性质相关方程,相关系数均在0.99以上。这些模型能较好地解释多氯联苯热力学性质的递变规律,而且相关系数高,稳定性好,预测能力强。采用留一法对模型稳健性进行了检验,得到的预测模型对另外一些多氯联苯分子的热力学性质进行预测,预测结果和文献值基本吻合。     

聚氧乙烯类和硫酸盐类表面活性剂HLB值的研究

亲水亲油平衡值(Hydrophile/Lipophile Balance,HLB)是表征表面活性剂性质的重要参数。采用比较分子力场分析(comparative molecular field analysis,CoMFA)方法和比较分子相似性指数分析(comparative similarity indices analysis,CoMSIA)方法,研究了30个烷基酚聚氧乙烯醚系列非离子表面活性剂的三维定量结构与pHLB值的关系。建立的CoMFA模型交叉验证系数为0.705,非交叉验证系数为0.805:CoMSIA模型交叉验证系数为0.685,非交叉验证系数为0.813,都有较好的预侧能力。此外,运用多元线性回归方法建立一种预报硫酸盐类表面活性剂HLB的QSPR模型,模型的复相关系数为0.711。所有选取的测试集和训练集的预报结果较为吻合,说明硫酸盐类表面活性剂HLB值QSPR模型具有良好的预报能力和普适性。     

定量结构-性质关系在化合物溶解度预测中的研究进展

溶解度是物质十分重要的一种理化性质,其在化工过程、药物和环境等领域的重要性不可忽视.定量结构-性质关系(quantitative structure-property relationship,QSPR)在化合物溶解度预测中得到广泛的应用.本文介绍了QSPR方法建立溶解度预测模型的研究进展,在总结各类分子描述符和构建溶解度预测模型方法的基础上,分别归纳出三类分子描述符(组成描述符、试验参数及理论计算描述符)和建模方法(线性、非线性及两者联合法),并从不同角度分析它们各自所拥有的特点,比较三类建模的优缺点.最后论述了当前溶解度QSPR研究中存在的不足及未来溶解度预测模型的发展趋势,指出溶解度的预测模型精度有待进一步提高,今后应更关注对化合物在不同pH值、温度、溶剂等更复杂情况下的溶解度预测.     

Quantitative structure-property relationship study on first reduction and oxidation potentials of donor-substituted phenylquinolinylethynes and phenylisoquinolinylethynes: Quantum chemical investigation

The relationship between the chemical structure, first reduction and oxidation potentials of 30 Phenylquinolinylethyne (PhQE), and Phenylisoquinolinylethyne (PhIE) derivative compounds has been elucidated employing ab initio calculations. Quantum chemical calculations (HF/6-31G) were carried out to obtain: the optimized geometry, energy levels, quantum chemical indices, charges and dipole moments of these compounds. The quantitative structure-property relationship (QSPR) of PhQE and PhIE was studied for the first reduction (E_red), and the first oxidation (E_ox) potentials. The genetic algorithm (GA) was applied to select the variables that resulted in the best-fit models. After the variable selection, multiple linear regression (MLR) was utilized to construct linear QSPR models. The resulting QSPR equations indicated that the orbital energies, quantum chemical indices (i.e. electronegativity and softness) and localization of charge in molecules are important factors in the first oxidation and reduction potentials of PhQE and PhIE. The quantum-chemical calculations show that the HOMO and LUMO of both PhQE and PhIE derivatives are localized on the donor-substituted phenyl moiety, and the quinolinyl and isoquinolinyl acceptor moiety respectively. Thus, it was proposed that the first reduction and oxidation potentials can be ascribed to reduction at the quinolinyl acceptor moiety, and oxidation at the donor-substituted phenyl moiety.     

多氯联苯醚和多溴联苯醚理化性质的定量结构-性质关系研究

多氯联苯醚(PCDEs)和多溴联苯醚(PBDEs)是分布广泛的污染物,有环境持久性和生物蓄积性。文中采用多元回归分析方法,以氯碎片常数为变量,建立了PCDE同类物水中溶解性、正辛醇/水分配系数、蒸汽压(293 K)等理化性质的线性关联式,也建立了PBDE同类物正辛醇/水分配系数、正辛醇/空气分配系数、蒸汽压(293 K)等理化性质的关联式。关联式对PCDEs和PBDEs的理化性质进行了估算,其结果与文献报道的实验值相当吻合。结果表明:采用PCDEs/PBDEs分子中氯/溴取代总数、氯/溴的邻位取代数目和相邻取代位置上均为氯/溴取代的成对数目作为变量,可以表述PCDEs/PBDEs的定量结构-性质关系。利用简单易得的描述符建立的QSPR模型是合理的、适用的。