Studies on Enantioselective Bioactivity,Ecotoxicity,and Environmental Behavior of Famoxadone

Author:Xu Guo Feng

Supervisor:li xing hai

Database:Doctor

Degree Year:2019

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Pages:115

Size:5352K

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Famoxadone,a broad spectrum systemic chiral fungicide,was extensively used in fruits and vegetables.The commercial famoxadone is racemate.The different stereoisomers of the same chiral pesticide may differ dramatically in bioactivity to target,toxicity to non-target organisms,and degradation in different environment.The data obtained were incomplete and nonspecific by conventional risk evaluations for chiral pesticides,these pesticides can bring potential risks to environment and public health.In this thesis,the absolute configuration stability,bioactivity,ecotoxicity and environmental behavior of famoxadone enantiomers were systemically studied.The result of this study will provide more accurate data support for the risk assessment of chiral pesticide.1.The separation and analytical method of famoxadone enantiomers were developed using UPLC-MS/MS.Famoxadone enantiomers were seperated by Lux Amylose-1,mobile phase: acetonitrile/water=70/30,flow rate: 0.3 mL/min and column temperature: 25℃.The absolute configuration of famoxzdone enantiomers were measured through time-dependent density functional theory calculation for circular dichromatographic and the circular dichromatographic by experiment.The elution order for famoxzdone enantiomers were R-(-)-famoxzdone and S-(+)-famoxzdone.2.The stability of photolysis and hydrolysis for famoxadone enantiomer were evaluated.The photostability were tested in 6 solvents,and water stability were tested in 3 kind of pH buffer solution.The results shown that significant difference were not observed during photolysis and hydrolysis.The absolute configuration of famoxadone enantiomer remained stable in photolysis test and hydrolysis test.3.The bioactivity and the acute aquatic toxicity of famoxadone enantiomer were studied.Famoxadone enantiomer against Alternaria solani,Phytophthora infestans,Botryosphaeria dothidea,Colletotrichum gloeosporioides,Plasmopara viticola were evaluated.The results showed that the bioactivities of famoxadone enantiomer were difference,the order of bioactivity of famoxadone enantiomer was found to be S-(+)-famoxadone >Rac-famoxadone > S-(-)-famoxadone and the maximum activity differential multiple is 40.5for Botryosphaeria dothidea.The acute aquatic toxicity of famoxadone enantiomer to Selenastrum bibraianum,Daphnia magna Straus and Brachydanio rerio were evaluated.The acute aquatic toxicity of famoxadone enantiomer were difference,the order of the toxicity was R-(-)-famoxadone > Rac-famoxadone > S-(+)-famoxadone and the maximum acute aquatic toxicity differential multiple is mora than 100 for Brachydanio rerio.4.The enantioselective dissipation of famoxadone in greenhouse tomato,apple and grape were studied.The result indicated that the degradation process of famoxadone enantiomer coincided the pseudo-first order,reaction dynamic model and significant stereoselectivity was observed in tomato,apple and grape under foliar spraying application mode.The value of EF was 0.491 to 0.649.S-(+)-famoxadone was preferentially degraded in greenhouse tomato,apple and grape.5.The enantioselective dissipation of famoxadone in the brewing of apple cider and grape wine were studied.The result indicated that the degradation process of famoxadone enantiomer coincided the pseudo-first order,reaction dynamic model in the winemaking biological systems and significant stereoselectivity was observed.R-(-)-famoxadone was preferentially degraded and S-(+)-famoxadone was relatively concentrated in the winemaking.PFs were 0.014-0.024 during the winemaking,the winemaking can reduce the amount of famoxadone residue.6.The enantioselective dissipation of famoxadone in different soils was evaluated.The result shown that there was significant dissipation difference for famoxadone enantiomer in three kind of soils both under aerobic condition,The value of EF was 0.435 to 0.498.R-(-)-famoxadone was preferentially degraded and led to an enrichment of S-(+)-famoxadone.There was no significant dissipation difference for famoxadone enantiomer in three kinds of soils under anaerobic condition and the half-lives are simila.The absolute configuration of famoxadone enantiomer remained stable both under aerobic and anaerobic condition in three kind soils.