【作者】 徐国锋；

【导师】 李兴海；

【作者基本信息】 沈阳农业大学 ， 农药学， 2019， 博士

【摘要】 噁唑菌酮是广泛使用的一种广谱性手性杀菌剂,在水果和蔬菜生产中广泛应用,商品化的噁唑菌酮是以外形消旋体的形式存在的。由于手性农药的立体异构体可能具有不同的生物活性、生态毒性以及不同的选择性降解行为,所以不区分立体异构体进行手性农药的风险评估,其结果缺乏科学性、准确性,存在很大的健康安全和环境安全隐患。本论文系统研究了噁唑菌酮对映体的构型稳定性、生物活性、生态毒性和不同条件下的环境行为,为噁唑菌酮的安全风险评估和开发应用提供科学的理论依据。1.建立了UPLC-MS/MS分离噁唑菌酮对映体的分析方法。在采用Lux Amylose-1手性固定相,流动相:乙腈/水=70/30,流速:0.3 mL/min,柱温:25℃条件下实现了噁唑菌酮的基线分离,分离度为1.78;通过含时密度泛函理论模拟电子圆二色谱与试验获得的圆二色谱相比较,确定了噁唑菌酮的流出顺序为R-(-)-噁唑菌酮和S-(+)-噁唑菌酮。2.开展了噁唑菌酮对映体的光解稳定性和水解稳定性研究。在6种溶剂中,光解速率顺序为:甲醇<乙腈<异丙醇<丙酮<乙酸乙酯<水;在3种不同pH缓冲溶液中的水解速率为:pH 9缓冲液>pH 7缓冲液>pH 4缓冲液;噁唑菌酮对映体在相同条件下的光解、水解半衰期基本一致,无选择性降解行为;对映体构型稳定,未出现消旋化现象。3.开展了噁唑菌酮对映体的生物活性和生态毒性研究。通过对番茄早疫病、番茄晚疫病、苹果轮纹病、葡萄炭疽病、葡萄霜霉病等5种病原菌的生物活性差异研究发现,噁唑菌酮对映体对所选5种病原真菌的生物活性顺序为:S-(+)-噁唑菌酮>Rac-噁唑菌酮>R-(-)-噁唑菌酮,苹果轮纹病差异最大为40.5倍;通过对羊角月牙藻、大型溞和斑马鱼的急性毒性差异研究发现,噁唑菌酮对映体对羊角月牙藻、大型溞和斑马鱼的毒性顺序为:R-(-)-噁唑菌酮>Rac-噁唑菌酮>S-(+)-噁唑菌酮,斑马鱼的最大急性毒性差异最大为100倍以上。4.开展了噁唑菌酮在设施番茄,露天苹果和葡萄中的立体选择性降解研究。结果表明,噁唑菌酮对映体在3种作物中的降解过程均符合一级动力学方程,并且均存在立体选择性降解行为,EF值在0.491-0.649之间。在番茄、苹果和葡萄中S-(+)-噁唑菌酮相对于R-(-)-噁唑菌酮均优先降解。5.开展了噁唑菌酮在苹果酒和葡萄酒加工过程中的立体选择性降解研究。研究结果表明在酵母菌、果汁和果渣组成的环境条件下,噁唑菌酮对映体存在立体选择性降解,EF值在0.374-0.500之间;整个加工过程PF在0.014-0.024之间,加工过程能够减少噁唑菌酮的残留量。6.开展了噁唑菌酮在不同土壤中的对映体选择性降解研究。结果表明,在三种供试土壤中,有氧条件下噁唑菌酮对映体降解均存在对映体选择性,EF值在0.4347-0.4975之间,表现为R-(-)-噁唑菌酮降解速度快于S-(+)-噁唑菌酮;在厌氧条件下,噁唑菌酮无选择性降解行为。噁唑菌酮对映体在有氧和厌氧土壤条件下,半衰期基本相近,不存在选择性降解行为;对映体构型稳定,未出现消旋化现象。更多还原

【Abstract】 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.更多还原