Fluoxapyr And Its Metabolites In Non-targetStudy On The Enrichment And Degradation Of Model Organism Xenopus Tadpoles

Sulfoxaflor is a fourth-generation neonicotinoid pesticide developed by Dow Agro Sciences Inc.and registered for the control of rice planthoppers.This subject study the environmental behavior of chlorpyranid,the toxic effect on the amphibian model animal Xenopus tadpoles,and the metabolic level of major metabolites,providing a scientific basis for the safety evaluation of chlorfenapyr in amphibians.The following research work was carried out in the paper:based on the results of JMPR research,five major metabolites of sulfoxaflor were synthesized and identified;the analytical methods of sulfoxaflor and its five major metabolites were established in water,soil and Xenopus tadpoles;the water degradation,photodegradation and soil degradation environmental behaviors of sulfoxaflor were studied;the acute toxicity and sub-slow toxicity tests of Xenopus tadpoles were carried out,and the toxic effect and bioconcentration behavior were studied.Obtain the following research results1.Researched and designed the synthesis route of 5 main metabolites of sulfoxaflor,synthesizing X11718922 with 1-trifluoromethylpyridine-4acetic acid;synthesizing X11721061with sodium borohydride using X11718922;synthesizing X11821639 with X11718922;X11721061 synthesizes X11519540;3-115-2-trifluoromethylpyridine is used to synthesize X11596066.It was verified by HRMS,¹³CNMR and ¹HNMR.2.An analytical method was established for sulfoxaflor and its metabolites in salamander tissue,water,and soil.The results showed that the concentration of sulfoxaflor and its metabolites had a good linear relationship with the peak area in the linear range,and the correlation coefficient R²>0.99.The average addition recovery of sulfoxaflor and its metabolites in the matrix of 3 was90.19%-107.64%,and the RSD was 1.22%-6.06%.The stability,sensitivity,accuracy and precision of the analytical method meet the detection requirements.3.The results of hydrolysis and soil degradation showed that sulfoxaflor was difficult to hydrolyze in different temperatures and p H;The water content of soil and the content of sulfoxaflor in the soil are factors that affect the degradation of sulfoxaflor.With soil water content increasing and degradation rate accelerating,the lower the content of sulfoxaflor in soil,the faster the degradation;Lower concentrations of metabolites X11519540 and X11821639 were detected during hydrolysis and soil degradation.The photolysis test showed that the photolysis rate of sulfoxaflor was related to the initial concentration of sulfoxaflor,the p H value of the buffer solution,and the light intensity.The smaller the initial concentration,the greater the p H of the buffer solution and the stronger the light intensity.Three kinds of metabolites are produced during the photolysis process,which are X11721061,X11519540,and X11718922,of which X11721061and X11718922 are the main photolysis products,and the content of X11519540 is low.X11721061 Photolysis occurs when the photolysis reaches the threshold.4.The acute toxicity test showed that sulfoxaflor was low-toxic to Xenopus tadpoles,and there was no obvious LC50 dose-effect relationship within 96 hours.5.Subchronic toxicity experiments showed that sulfoxaflor has the following effects on the morphology,antioxidant system and endogenous amino acids of Xenopus tadpoles:1)Sub-chronic toxicity experiments have shown that sulfoxaflor has an inhibitory effect on the body weight,volume,tail muscle height,and low-density development of Xenopus laevis in developmental stages 46-50;2)Physiological tests indicate that fipronil affects the antioxidant enzyme activity of Xenopus tadpoles.It is detoxified in phase II by the increase of the enzyme activity level of GST and GR,and in phase I is detoxified by biotransformation between metabolites.3)Enrichment-degradation studies indicate that sulfoxaflor may affect the metabolism of Cys,Try,and Thr in tadpoles.The symptoms of poisoning and the mechanism of detoxification are related to amino acid metabolism.6.Bioconcentration tests showed that sulfoxaflor increased and decreased during the Xenopus laevis accumulation process.Sulfoxaflor was rapidly eliminated during the degradation process,and the half-life was less than 1 d.The BCFXd is less than 2,and the BCF is 0.0743 and 0.0352,respectively,indicating that Xenopus laevis has a weak bioconcentration behavior to sulfoxaflor.sulfoxaflor in tadpole tissue is rapidly eliminated in clean water,and the enrichment behavior may be concentration-dependent.Each metabolite was less than 0.82 mg/kg during enrichment,and metabolites were detected during degradation7.The secondary metabolism of sulfoxaflor and its metabolites in Xenopus laevis was studied.It was found that sulfoxaflor can produce these five metabolites at different times.When these five compounds are used alone,the remaining compounds can be produced at different times,and there is a certain conversion relationship between these metabolites.The toxicity of metabolite X11519540 may be higher.The conversion rate of sulfoxaflor and compounds X11721061,X11596066,X11718922 in tissues is faster,and the conversion rate of X11519540 is slower..