Synthetic Strategies for the Development of Novel Heterocycles as Larvicides Targeting Aedes aegypti Linn.

Background: Owing to their extensive utilization as pesticides, heterocycles assume a fundamental role in the management of vector-borne diseases. Despite the presence of numerous heterocyclic compounds in commercial insecticides and larvicides, resistance to pesticides still demands novel strategies to current pest control methods. Considering these facts, this review aims to survey the synthesis and SAR of heterocyclic molecules with larvicidal activity against Aedes aegypti Linn.

Methods: Comprehensive searches across the major databases were conducted to identify heterocyclic compounds exhibiting larvicidal efficacy against Ae. aegypti with the goal to unveil the main characteristics that are essential for exhibiting larvicidal activity.

Results: Active compounds display LC50 values varying from 0.36 to 2907 μM. Fifteen heterocyclic compounds displayed larvicidal activities below 20 μM. Five-membered ring molecules containing nitrogen and oxygen have displayed larvicidal activity according to the position of heteroatoms in the ring. Molecules bearing 1,2,4-oxadiazole and 1,2-oxazole moieties have been shown to be more active than 1,3,4-oxadiazole derivatives. Compounds possessing the indole scaffold have proven to be more potent than isatin and pyrimidine derivatives. Structural characteristics other than a heterocyclic moiety, such as the presence of halogens and less ionized and polar molecules, may also play a role in determining the final larvicidal activity.

Conclusion: The rationale behind this review is to stimulate the discovery of innovative heterocyclic larvicides. Thus, it is important to continue synthesizing new scaffolds to comprehensively elucidate the structure-activity relationship for each heterocyclic moiety outlined in this investigation.