Enantioselective Bioactivity, Toxicity, and Degradation in Vegetables and Soil of Chiral Fungicide Mandipropamid

Abstract

Mandipropamid (MDP) is a widely used chiral fungicide to control oomycete pathogens with two enantiomers. In this study, the enantioselective bioactivity, toxicity, and degradation of MDP were investigated for the first time. The bioactivity of S-MDP was 118–592 times higher than that of R-MDP and 1.14–1.67 times higher than that of Rac-MDP against six phytopathogens. Molecular docking found that S-MDP formed a strong halogen bond with HIS 693 of cellulose synthase and possessed a lower binding energy, which validated the results of the bioactivity assay. S-MDP showed lower toxicity toward Spirodela polyrhiza, while it exhibited higher toxicity in Danio rerio embryo and larva. S-MDP preferentially degraded in cowpea and pepper, while R-MDP preferentially degraded in soil. There is no significant difference between the two enantiomers in the toxicity of adult D. rerio and in cucumber degradation. Therefore, the development of the S-enantiomer was considered as a better option to exhibit high efficiency, which could reduce the residual risk of the pesticide and ensure environmental safety.

Effects of Household Processing on Residues of the Chiral Fungicide Mandipropamid in Four Common Vegetables

“…An EF value of 0.5 indicates no enantioselectivity. Moreover, the S -enantiomer is preferentially removed for EF values in the range of 0.5–1 [ 21 , 30 ].…”

Enantioselective Degradation and Bioactivity Mechanism of a New Chiral Fungicide Fluindapyr in Paddy Ecosystems

“…13 The bioactivity of Smandipropamid was 118−592 times greater than that of Rmandipropamid against six plant pathogens. 14 S-Triticonazole had greater acute toxicity to non-target aquatic and terrestrial organisms. 15 The toxicity of R-oxathiapiprolin to aquatic plants and zebrafish was higher than that of S-oxathiapiprolin, 16 and R-oxathiapiprolin had greater distribution in animal tissue (liver and lungs).…”

“…Based on the supercritical fluid chromatography-tandem mass spectrometry method, S -diniconazole was preferentially degraded in fruits . The bioactivity of S -mandipropamid was 118–592 times greater than that of R -mandipropamid against six plant pathogens .…”

Systemic Stereoselectivity Study of Fenobucarb: Environmental Behaviors in Greenhouse Vegetables, Fruits, Earthworms, and Soils and Its Cytotoxicity

“…10−14 Research groups such as Zhang et al compared the enantioselective bioactivity against six phytopathogens, the toxicity in the Danio rerio embryo and larva, and the degradation in cowpea, pepper, and soil of the chiral fungicide Mandipropamid, and the results revealed that the development of the S-enantiomer would be considered as a better option to exhibit high efficiency, which could reduce the residual risk of the pesticide and ensure environmental safety. 15 Therefore, it is essential to study the enantioselective bioeffects and environmental behaviors of chiral pesticides at the enantiomer level to obtain more accurate data. The enantiomer of chiral pesticides could be more effective against insects and less toxic to nontarget organisms and so would improve the food safety and reduce environmental risks.…”

“…With the increase in the awareness of food safety and human health, more and more researchers have begun to pay much attention to chiral pesticides for the assessment of a possible replacement of commercial racemate with a single stereoisomer. It has been reported that the chiral pesticide enantiomers that had identical physicochemical properties showed enantioselectivity in biological activity, dissipation behavior, bioaccumulation, transformation, and biological metabolism when they were introduced to a chiral environment. − Moreover, a significantly different toxicity effect of chiral pesticide enantiomers is also often exhibited in cancer promotion, cytotoxicity, and endocrine disruption to nontarget biota. − Research groups such as Zhang et al compared the enantioselective bioactivity against six phytopathogens, the toxicity in the Danio rerio embryo and larva, and the degradation in cowpea, pepper, and soil of the chiral fungicide Mandipropamid, and the results revealed that the development of the S -enantiomer would be considered as a better option to exhibit high efficiency, which could reduce the residual risk of the pesticide and ensure environmental safety . Therefore, it is essential to study the enantioselective bioeffects and environmental behaviors of chiral pesticides at the enantiomer level to obtain more accurate data.…”