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

Abstract

Fluindapyr is a novel chiral succinate dehydrogenase inhibitor used to control fungal diseases. The enantioselective effects of fluindapyr in paddy ecosystems are unknown. We developed a new chiral determination method of fluindapyr using ultrahigh performance liquid chromatography tandem mass spectrometry. The absolute configuration of the fluindapyr enantiomers was identified by an electron circular dichroism model. A new husk-based biochar material was used to optimize and establish a QuEchERs method for paddy soil determination. Under anaerobic conditions, the half-lives of R-fluindapyr and S-fluindapyr in paddy soil were 69.6 and 101.8 days, respectively. R-fluindapyr degraded more rapidly than S-fluindapyr. S-fluindapyr was 87.8 times more active against Rhizoctonia solani than R-fluindapyr. The enantioselective bioactivity mechanism was illustrated by molecular docking between the fluindapyr enantiomers and SDH of R. solani. The binding powers of R-fluindapyr and S-fluindapyr to proteins were −32.12 and − 42.91 kcal/mol, respectively. This study reports the stereoselectivity of fluindapyr about determination, degradation, bioactivity, and its mechanism. It provides a foundation for an in-depth study of fluindapyr at the enantiomer level.

Absolute Configuration, Enantioselective Bioactivity, and Mechanism Study of the Novel Chiral Fungicide Benzovindiflupyr

“…The enantioselective antifungicidal activities of benzovindiflupyr were evaluated in vitro against phytopathogenic fungi via mycelial growth inhibition . Differences in antifungicidal activities exist at the enantiomeric level . The racemate and enantiomers of benzovindiflupyr dissolved in acetone were mixed with PDA at a concentration of 50 μg/mL and then poured into sterilized Petri dishes.…”

“…25 Differences in antifungicidal activities exist at the enantiomeric level. 26 The racemate and enantiomers of benzovindiflupyr dissolved in acetone were mixed with PDA at a concentration of 50 μg/mL and then poured into sterilized Petri dishes. Acetone and hymexazol were used as controls, and a commercial agricultural fungicide was used as the positive control.…”

Recent developments in fluorine‐containing pesticides

“…The racemic fluindapyr (Onsuva, FMC, Isagro) contains an additional fluorine atom found in the 7‐fluoro‐1,1,3‐trimethyl‐indan‐4‐yl moiety (Table 6) and can be used for preventive and curative control of fungal diseases in various key crops such as cereals, soybeans, corn, oilseed rape, fruits and vegetables, tree nuts and peanuts. After separation of the enantiomers was found, that (R)‐ fluindapyr degrades more rapidly in paddy soil than (S)‐ fluindapyr, whereas the (S)‐ enantiomer is more active against brown patch ( R. solani ) than the (R)‐ enantiomer 47 . In the mixture Kalida, fluindapyr is combined with the long known fluorinated DMI fungicide flutriafol (1984, ICI, Zeneca), The product provides complete protection against bipolaris leaf spot (BLS) ( Bipolaris incurvata ), take‐all root rot ( Gaeumannomyces graminis var.…”

Quinoline Derivatives in Discovery and Development of Pesticides

“…Pyrazoles are well-known pharmacophores that have played a huge role in the discovery of new pesticides, such as pyrazolecarboxamide-based SDH inhibitors and chlorfenapyr. − Compounds 49 and 50 (Figure ) were designed to be synthesized through the combination of quinoline with pyrazole. For example, the insecticidal activity of compound 49 against Plutella xylostella Linnaeus was 70.0%, at 200 mg/L .…”