市政水体及实际水环境中各类复杂混合污染物的暴露已成为普遍现象,且对人体健康的危害不断在加剧.随着混合物联合毒性的研究越来越多,使得混合物联合毒性作用的研究成为了一个重要领域.为探索重金属混合毒性作用特点,选取水环境中较敏...市政水体及实际水环境中各类复杂混合污染物的暴露已成为普遍现象,且对人体健康的危害不断在加剧.随着混合物联合毒性的研究越来越多,使得混合物联合毒性作用的研究成为了一个重要领域.为探索重金属混合毒性作用特点,选取水环境中较敏感的斜生栅藻为指示生物,实际环境中常见的六种重金属(锌Zn、镍Ni、铬Cr、铜Cu、砷As和铅Pb)为目标污染物,通过等效应浓度比法(equal-effect concentration ratio method,ECRR)设计一系列二元混合物联合毒性试验,研究二元重金属混合物联合胁迫下的斜生栅藻96 h毒性及其相互作用.结果表明:以EquRay设计的45条二元重金属混合物射线,测试混合物对斜生栅藻的毒性效应.分析45条混合物射线相互作用,重金属二元混合物中7条为加和作用,37条为协同作用,1条为拮抗作用.重金属混合预测决定系数大于0.95,均方根误差小于0.08,具有较好的拟合显著性和统计性.展开更多
Pesticides released into the environment may pose potential risks to the ecological system and hu-man health.However,existing toxicity data on pesticide mixtures still lack,especially regarding the toxic interac-tions...Pesticides released into the environment may pose potential risks to the ecological system and hu-man health.However,existing toxicity data on pesticide mixtures still lack,especially regarding the toxic interac-tions of their mixtures.This study aimed to determine the toxic interactions of binary mixtures of pesticides on Scenedesmus Obliquus(S.obliquus)and to build quantitative structure-activity relationship models(QASR)for predicting the mixture toxicities.By applying direct equipartition ray method to design binary mixtures of five pes-ticides(linuron,dimethoate,dichlorvos,trichlorfon and metribuzin),the toxicity of a single pesticide and its mix-ture was tested by microplate toxicity analysis on S.obliquus.The QASR models were built for combined toxicity of binary mixtures of pesticides at the half-maximal effective concentration(EC_(50)),30%maximal effective concen-tration(EC_(30))and 10%maximal effective concentration(EC_(10)).The results showed that the single toxicity follows:metribuzin>linuron>dichlorvos>trichlorfon>dimethoate.The mixtures of linuron and trichlorfon,dichlorvos and metribuzin,dimethoate and metribuzin induced synergetic effects,while the remaining binary mixtures exhib-ited additive.The developed QSAR models were internally validated using the leave-one-out cross-validation(LOO),leave-many-out cross-validation(LMO),bootstrapping,and y-randomization test,and externally validated by the test sets.All three QSAR models satisfied well with the experimental values for all mixture toxicities,and presented high internally(R^(2)and Q^(2)>0.85)and externally(Q^(2)_(F1),Q^(2)_(F2),and Q^(2)_(F3)>0.80)predictive powers.The developed QSAR models could accurately predict the toxicity values of EC_(50),EC_(30)and EC_(10)and were superior to the concentration addition model's results(CA).Compared to the additive effect,the QSAR model could more ac-curately predict the binary mixture toxicities of pesticides with synergistic effects.展开更多
The wide use of quaternary ammonium cationic surfactants(QACs)results in their release into the environment.Most surfactants have significant biotoxicity.However,existing toxicity data on QACs are still lacking,especi...The wide use of quaternary ammonium cationic surfactants(QACs)results in their release into the environment.Most surfactants have significant biotoxicity.However,existing toxicity data on QACs are still lacking,especially regarding the joint toxic effects of their mixtures.In computer simulation technology,molecular docking technology is commonly used for studying the mode of action of receptors docking with ligands.The research of QACs mixture interaction is relatively rare,and the binding mode of QACs is unknown.In this study,molecular docking technology was applied to explore the QAC binding mode,and the concentration addition(CA)and independent action(IA)models were applied for predicting the mixture toxicity.Firefly luciferase(FLuc)was used as a macromolecular receptor,and five typical QACs:benzalkonium bromide(BLB),tetraethylammonium bromide(TLB),N,N,N-trimethyl-1-tetradecyl ammonium bromide(CTE),tetrabutylammonium chloride(TAC),and dodecyltrimethylammonium chloride(DTC)were used as small molecule ligands.Molecular docking technology was used to investigate the binding mode of macromolecules and small molecules.The luminescence inhibitory effects of individual compounds and binary mixture on FLuc were determined by microplate toxicity assay of luciferase.The prediction of mixture toxicity was performed by CA and IA.The results showed that the relative toxicity follows:TLB<TAC<DTC<BLB<CTE.TLB and TAC showed the BS-Ⅱbinding mode,and BLB,CTE and DTC showed the BS-Ⅲbinding mode.The toxicity of compounds with binding mode BS-Ⅱwas less than that of those with BS-Ⅲbinding mode.Not all mixtures with the same binding mode could be predicted by CA model,and the IA model did not effectively predict the toxicity of mixtures with compound with different binding modes.The mixture toxicities of QACs with the same binding mode mostly presented additive and synergistic effects,while the mixture toxic effects of QACs with different binding modes presented additive or antagonistic effects.展开更多
文摘市政水体及实际水环境中各类复杂混合污染物的暴露已成为普遍现象,且对人体健康的危害不断在加剧.随着混合物联合毒性的研究越来越多,使得混合物联合毒性作用的研究成为了一个重要领域.为探索重金属混合毒性作用特点,选取水环境中较敏感的斜生栅藻为指示生物,实际环境中常见的六种重金属(锌Zn、镍Ni、铬Cr、铜Cu、砷As和铅Pb)为目标污染物,通过等效应浓度比法(equal-effect concentration ratio method,ECRR)设计一系列二元混合物联合毒性试验,研究二元重金属混合物联合胁迫下的斜生栅藻96 h毒性及其相互作用.结果表明:以EquRay设计的45条二元重金属混合物射线,测试混合物对斜生栅藻的毒性效应.分析45条混合物射线相互作用,重金属二元混合物中7条为加和作用,37条为协同作用,1条为拮抗作用.重金属混合预测决定系数大于0.95,均方根误差小于0.08,具有较好的拟合显著性和统计性.
基金Financially supported from the National Key Research and Development Program of China (2019YFC0507502)Guangxi Science and Technology Major Special Project (Guike-AA2016004)+2 种基金Natural Science Foundation of Guangxi Province (2018GXNSFAA281156)Guilin Scientific Research and Technology Development Program (20180107-5, 20180101-1)Guangxi ’Ba Gui Scholar’ Construction Projects
文摘Pesticides released into the environment may pose potential risks to the ecological system and hu-man health.However,existing toxicity data on pesticide mixtures still lack,especially regarding the toxic interac-tions of their mixtures.This study aimed to determine the toxic interactions of binary mixtures of pesticides on Scenedesmus Obliquus(S.obliquus)and to build quantitative structure-activity relationship models(QASR)for predicting the mixture toxicities.By applying direct equipartition ray method to design binary mixtures of five pes-ticides(linuron,dimethoate,dichlorvos,trichlorfon and metribuzin),the toxicity of a single pesticide and its mix-ture was tested by microplate toxicity analysis on S.obliquus.The QASR models were built for combined toxicity of binary mixtures of pesticides at the half-maximal effective concentration(EC_(50)),30%maximal effective concen-tration(EC_(30))and 10%maximal effective concentration(EC_(10)).The results showed that the single toxicity follows:metribuzin>linuron>dichlorvos>trichlorfon>dimethoate.The mixtures of linuron and trichlorfon,dichlorvos and metribuzin,dimethoate and metribuzin induced synergetic effects,while the remaining binary mixtures exhib-ited additive.The developed QSAR models were internally validated using the leave-one-out cross-validation(LOO),leave-many-out cross-validation(LMO),bootstrapping,and y-randomization test,and externally validated by the test sets.All three QSAR models satisfied well with the experimental values for all mixture toxicities,and presented high internally(R^(2)and Q^(2)>0.85)and externally(Q^(2)_(F1),Q^(2)_(F2),and Q^(2)_(F3)>0.80)predictive powers.The developed QSAR models could accurately predict the toxicity values of EC_(50),EC_(30)and EC_(10)and were superior to the concentration addition model's results(CA).Compared to the additive effect,the QSAR model could more ac-curately predict the binary mixture toxicities of pesticides with synergistic effects.
基金Financially supported from the National Natural Science Foundation of China (21667013 and 21866010)Natural Science Foundation of Guangxi Province (2018GXNSFAA281156)+2 种基金Guilin Scientific Research and Technology Development Program (20180107-5)Special Funding for Guangxi’BaGui Scholar’Construction ProjectsGuangxi Key Laboratory of Environmental Pollution Control Theory and Technology for Science and Education Combined with Science and Technology Innovation Base。
文摘The wide use of quaternary ammonium cationic surfactants(QACs)results in their release into the environment.Most surfactants have significant biotoxicity.However,existing toxicity data on QACs are still lacking,especially regarding the joint toxic effects of their mixtures.In computer simulation technology,molecular docking technology is commonly used for studying the mode of action of receptors docking with ligands.The research of QACs mixture interaction is relatively rare,and the binding mode of QACs is unknown.In this study,molecular docking technology was applied to explore the QAC binding mode,and the concentration addition(CA)and independent action(IA)models were applied for predicting the mixture toxicity.Firefly luciferase(FLuc)was used as a macromolecular receptor,and five typical QACs:benzalkonium bromide(BLB),tetraethylammonium bromide(TLB),N,N,N-trimethyl-1-tetradecyl ammonium bromide(CTE),tetrabutylammonium chloride(TAC),and dodecyltrimethylammonium chloride(DTC)were used as small molecule ligands.Molecular docking technology was used to investigate the binding mode of macromolecules and small molecules.The luminescence inhibitory effects of individual compounds and binary mixture on FLuc were determined by microplate toxicity assay of luciferase.The prediction of mixture toxicity was performed by CA and IA.The results showed that the relative toxicity follows:TLB<TAC<DTC<BLB<CTE.TLB and TAC showed the BS-Ⅱbinding mode,and BLB,CTE and DTC showed the BS-Ⅲbinding mode.The toxicity of compounds with binding mode BS-Ⅱwas less than that of those with BS-Ⅲbinding mode.Not all mixtures with the same binding mode could be predicted by CA model,and the IA model did not effectively predict the toxicity of mixtures with compound with different binding modes.The mixture toxicities of QACs with the same binding mode mostly presented additive and synergistic effects,while the mixture toxic effects of QACs with different binding modes presented additive or antagonistic effects.
