可用于表征可电离化合物离子化影响的描述符研究进展  

Progress in Descriptors Used to Correct Influence of Ionization for Ionizable Organic Chemicals

作　　者：杨先海 刘会会 王连军 Yang Xianhai;Liu Huihui;Wang Lianjun(Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse,School of Environmental and Biological Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学环境与生物工程学院,江苏省化工污染控制与资源化高校重点实验室,南京210094

出　　处：《生态毒理学报》2021年第5期1-13,共13页Asian Journal of Ecotoxicology

基　　金：中国博士后科学基金资助项目(2020T130301,2020M671502);江苏省博士后科研资助计划项目(2020Z288)。

摘　　要：在人为有意生产的化学品或无意识产生的化学品中,可电离有机化合物(IOCs)均占有较大比重。在环境水体、生理或实验pH条件下,IOCs可解离为分子和离子形态。研究表明,IOCs的分子和离子形态均对其表观物理化学、环境归趋和行为、生态和健康毒性效应参数具有不可忽视的影响,因而在开展IOCs相关实验或理论研究时不应忽略离子化的影响。在构建IOCs相关预测模型时,核心是如何表征离子化的影响。本文从描述符入手,总结了可用于表征IOCs离子化影响的4类描述符,即酸碱解离常数(pK_(a))及其衍生参数(分子态和离子态的比例分数(δ_(分子)和δ_(离子)))、考虑离子化影响的分配系数包括正辛醇-水分布系数(logD_(OW)(pH))和进行形态修正的脂质体-水分配系数(logD_(lip/w)(pH))、考虑离子参数的多参数线性自由能关系(离子描述符J^(+)和J^(-))、基于形态修正的量化参数,并展望了表征IOCs离子化影响的未来研究重点。Ionogenic organic chemicals(IOCs)are organic compounds with one or more ionizable function groups in their molecular structures.A large fraction of artificial chemicals or unintentional production chemicals are IOCs.Under the environmental,physiological and experimental pH condition,the IOCs may dissociate and exist as a mixture of neutral and ionized forms.It had been well documented that the neutral and ionized species of IOCs indeed had distinct physicochemical properties,environmental fate and behavior,ecological and health toxic effects.The observed parameters,properties,or endpoints influenced by ionization include but not limited to partition coefficients,photolysis rate constant,rate constants of hydroxyl radical,the adsorption capability to zeolite,bioconcentration,aquatic toxicity on fish,Daphnia magna,algae,Tetrahymena pyriformis,protein binding interaction,and so on.In addition,the previous studies also implied that both forms of IOCs may contribute to their observed aforementioned apparent parameters.Thus,ionization should not be ignored in the related experimental and theoretical research of IOCs.Hitherto,how to correct the influence of ionization is one of the critical issues in deriving the predictive models(e.g.(quantitative)structure-activity/property relationship((Q)SA/PR))for IOCs.In this work,the available descriptors could be used to describe the effect of ionization for IOCs in the modeling were reviewed and summarized.Those descriptors include acid dissociation constant(pK_(a))and derived parameters(the fractions of the neutral(δ_(M))and ionized species(δ_(I))at a given pH),distribution coefficient(the n-octanol/water distribution coefficient(logD_(OW)(pH))and speciation-corrected liposome-water distribution ratios(logD_(lip/w)(pH))),ionic descriptors in polyparameter linear free energy relationship(pp-LFER)equation(ionic descriptors J^(+)and J^(-)),chemical form adjusted quantum chemical descriptors.Further investigations in correcting the ionization of IOCs were further discussed.

关 键 词：可电离有机化合物 离子化 离子形态 分子形态 分配参数 水生生物毒性 描述符 量化描述符 定量结构-活性/属性关系 

分 类 号：X171.5[环境科学与工程—环境科学]