Enantioselective bioactivity, acute toxicity and dissipation in vegetables of the chiral triazole fungicide flutriafol

Zhang, Qing; Hua, Xiude; Shi, Haiyan; Liu, Jisong; Tian, Mingming; Wang, Minghua

doi:10.1016/j.jhazmat.2014.10.033

Cited by 99 publications

(59 citation statements)

References 21 publications

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“…In addition, the toxicity of the rac ‐bitertanol and the four stereoisomers increased as the exposure time extended, which was also observed in previous studies . In addition, many other studies have proved that triazole fungicides possess enantioselective toxicity on nontarget organisms . Therefore, it is necessary to consider the stereoselective toxicity when evaluating the effect of chiral pesticides on aquatic organisms.…”

Section: Resultssupporting

confidence: 71%

Stereoselective bioactivity, toxicity and degradation of the chiral triazole fungicide bitertanol

Gao

Wen

et al. 2019

Pest Management Science

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BACKGROUND The chiral pesticide bitertanol has been widely used in the prevention and treatment of fungal diseases on many crops. However, research on bitertanol at the stereoisomer level has not been reported. Here, we study the stereoselective bioactivity, toxicity, and degradation of this pesticide under laboratory and field conditions. RESULT (1S,2R)‐Bitertanol was the most effective stereoisomer, showing 4.3–314.7 times more potent bioactivity than other stereoisomers against eight target pathogenic fungi. (1S,2R)‐Bitertanol showed 10.2 times greater inhibition of Botrytis cinerea spore germination than (1R,2S)‐bitertanol. According to the receptor‐drug docking results, the distances from the nitrogen atom in the heterocycle of (1S,2R)‐, (1R,2S)‐, (1R,2R)‐, and (1S,2S)‐bitertanol to the central Fe + atoms in the ferriporphyrin were 2.5, 3.8, 2.6, and 3.8 Å, respectively. (1S,2S)‐Bitertanol was 1.6–2.7 times more toxic than (1R,2R)‐bitertanol to Chlorella pyrenoidosa. The half‐lives of (1R,2S)‐, (1S,2R)‐, (1R,2R)‐, and (1S,2S)‐bitertanol were 3.7, 4.1, 4.1, and 4.8 d, respectively, in tomato. CONCLUSION The stereoselective bioactivity, toxicity, and degradation for bitertanol were first studied here. (1S,2R)‐Bitertanol was a high efficiency and low toxicity stereoisomer. Moreover, the stereoselective bioactivity among all stereoisomers correlated with the binding distances and calculated energy differences between stereoisomers and the target protein. This study also provides a foundation for a systematic evaluation of bitertanol at the stereoisomer level. © 2019 Society of Chemical Industry

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Section: Resultssupporting

confidence: 71%

Stereoselective bioactivity, toxicity and degradation of the chiral triazole fungicide bitertanol

Gao

Wen

et al. 2019

Pest Management Science

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“…in chiral environments. For example, chiral pesticide enantiomers can differ in their toxicity and biological degradation due to the fact that the molecular receptor responsible for the toxicity or biological degradation of a pesticide is often an enzyme, the active center of which is also chiral and in turn enantioselective [2,[11][12][13][14][15]. Abiotic processes such as chemical, distribution, or transport processes are supposed to affect both enantiomers equally and are generally assumed to be non-enantioselective [10,16,17].…”

Section: Optical Isomers or Enantiomers Have Practically Identical Chmentioning

confidence: 99%

Enantioselective sorption of the chiral fungicide metalaxyl on soil from non-racemic aqueous solutions: Environmental implications

Celis

Gámiz

Facenda

et al. 2015

Journal of Hazardous Materials

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Mechanisms governing the enantioselectivity of the processes that determine the behavior of chiral pollutants in the environment need to be better understood. Understanding these mechanisms should help improve predictions of the hazards and risks chiral compounds can pose to people and the environment. We report the results of batch sorption experiments indicating that the sorption of the chiral fungicide metalaxyl on soil from non-racemic initial solutions was enantioselective. While from a racemic initial solution the two enantiomers of metalaxyl were sorbed on the soil to the same extent, increasing the fraction of R-enantiomer in the initial solution led to enhanced sorption of this enantiomer and to reduced sorption of the S-enantiomer. Considering the shape of the sorption isotherms (S-type) and the sorption behavior of model sorbents, we attributed this effect to molecular interactions between metalaxyl enantiomer species at the sorbed state, where R-R metalaxyl interactions appeared to be more favorable than R-S metalaxyl interactions. We discuss important environmental implications of the proposed mechanism, such as those related to the fact that the biological degradation of metalaxyl is known to be an enantioselective process that can yield non-racemic residues in soils shortly after application of the fungicide as a racemic mixture.

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“…The bioactivities of the enantiomers were evaluated using the inhibition rate. The inhibition rate and the median effective concentration (EC 50 ) were calculated by a data processing system (DPS) …”

Section: Methodsmentioning

confidence: 99%

“…The limit of quantification (LOQ) was the minimum concentration of bromothalonil that was validated with satisfactory recovery (70–120%) and precision (RSD ≤ 20%) by using the analytical method. The degradation rate constants (k) and half‐life (T 1/2 ) of the bromothalonil enantiomers in vegetables and soil were estimated according to the first‐order kinetic equations

C = {normalC}_{0} {normale}^{- kt}

{normalT}_{1 / 2} = \ln 2 / k = 0.693 / k

where C 0 and C are the concentrations of the enantiomers at time 0 and t separately.…”

Section: Methodsmentioning

confidence: 99%

Systemic stereoselectivity study of bromothalonil: stereoselective bioactivity, toxicity, and degradation in vegetables and soil

Liang

Huang

et al. 2020

Pest Management Science

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BACKGROUND The chiral pesticide bromothalonil is widely used to control anthracnose disease on fruits and vegetables in China. The pesticidal activity, ecotoxicological effects and environmental behavior of bromothalonil and its enantiomers are still unclear. RESULTS Bromothalonil presented effective biocidal activities against the tested fungi, its enantiomers showed distinct inhibitory activities against different fungal species. The bioactivities of (+)‐bromothalonil was 1.29–10.77 times higher than (−)‐bromothalonil toward Rhizoctonia solani, Botrytis cinerea, Curvularia lunata, Corynespora cassiicola, Colletotrichum siamense, and Colletotrichum musae, while the effect pattern was opposite for Colletotrichum cliviicola. Based on the acute toxicity test, bromothalonil was very toxic to Eisenia foetida (E. foetida). Bromothalonil also damaged the lysosomal membrane and exhibited potential genotoxicity toward E. foetida. Moreover, (+)‐bromothalonil presented lower toxicity than (−)‐bromothalonil. Stereoselective degradation was investigated in tomato, cucumber, chieh‐qua, and soil. The half‐life values of bromothalonil degradation ranged from 7.14 to 24.75 days, indicating that bromothalonil was easily degraded. Additionally, (+)‐bromothalonil degraded 1.2–1.75 times faster than (−)‐bromothalonil in the four matrices. CONCLUSION This is the first systemic assessment of the stereoselectivity of bromothalonil. Based on the obtained half‐life, EC50 and LC50 values, bromothalonil is an easily degraded, broad‐spectrum biocidal but very toxic pesticide. (+)‐Bromothalonil was more degradable in vegetables and soil and showed clearly higher bioactivity toward target organisms and lower toxicity to E. foetida than (−)‐bromothalonil. Therefore, the stereoselectivity of bromothalonil enantiomers should be fully considered in comprehensive environmental and ecological risk assessments in future work. © 2020 Society of Chemical Industry

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Enantioselective bioactivity, acute toxicity and dissipation in vegetables of the chiral triazole fungicide flutriafol

Cited by 99 publications

References 21 publications

Stereoselective bioactivity, toxicity and degradation of the chiral triazole fungicide bitertanol

Stereoselective bioactivity, toxicity and degradation of the chiral triazole fungicide bitertanol

Enantioselective sorption of the chiral fungicide metalaxyl on soil from non-racemic aqueous solutions: Environmental implications

Systemic stereoselectivity study of bromothalonil: stereoselective bioactivity, toxicity, and degradation in vegetables and soil

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