Synthesis, antimosquito activities, photodegradation, and toxic assessment of novel pyrethroids containing 2-chlorobiphenyl and 2-chlorophenylpyridine

Background: Aedes albopictus is a mosquito species and a vector of Dengue Virus and malaria parasites that represents a significant threat to global public health. Although mosquito populations have been effectively controlled through the use of synthetic insecticides, the emergence of widespread Insecticide resistance in wild mosquito populations is a strong motivation to explore new insecticidal chemistries.

Results: In this study, A. albopictus was treated with a series of novel pyrethroids containing 2-chlorobiphenyl and 2-chlorophenylpyridine via topical application. The relative antimosquito activity of each novel compound was determined, as measured by the LC₅₀ , and compared with the synthetic pyrethroid bifenthrin. The most antimosquito activity compound (SZ-B-11) was 4.69 times more active than bifenthrin. The novel compounds were also sensitive to wild A. albopictus. In addition, in silico toxicity assessment of aquatic organisms showed that the acute toxicity and chronic toxicity of SZ-B-11 were 31.96 times and 934.40 times lower than those of bifenthrin, respectively. Cytotoxicity assessment demonstrated that all tested compounds were nontoxic against SH-SY5Y cell lines. Furthermore, photolytic results suggested that SZ-B-11 would be photodegraded more easily than bifenthrin and would reduce secondary pollution.

Conclusion: Novel pyrethroids containing 2-chlorobiphenyl and 2-chlorophenylpyridine, through simple synthesis steps, have better antimosquito activity, low resistance, less ecotoxicity, readily degradable characteristics, and may reduce secondary pollution. They are promising insecticides with potential application prospects in agricultural production and environmental protection. © 2021 Society of Chemical Industry.

Aedes albopictus; photodegradation; resistance; synthetic pyrethroids; toxic assessment.