Synthesis of Novel 1,2,3-Triazole Derivatives of Isocoumarins and 3,4-Dihydroisocoumarin with Potential Antiplasmodial Activity In Vitro

Background: Malaria greatly affects the world health, having caused more than 228 million cases only in 2018. The emergence of drug resistance is one of the main problems in its treatment, demonstrating the need for the development of new antimalarial drugs. Objective: Synthesis and in vitro antiplasmodial evaluation of triazole compounds derived from isocoumarins and a 3,4-dihydroisocoumarin. Method: The compounds were synthesized in 4 to 6-step reactions with the formation of the triazole ring via the Copper(I)-catalyzed 1,3-dipolar cycloaddition between isocoumarin or 3,4-dihydroisocoumarin azides and terminal alkynes. This key reaction provided compounds with an unprecedented connection of isocoumarin or 3,4-dihydroisocoumarin and the 1,2,3-triazole ring. The products were tested for their antiplasmodial activity against a Plasmodium falciparum chloroquine resistant and sensitive strains (W2 and 3D7, respectively). Results: Thirty-one substances were efficiently obtained by the proposed routes with an overall yield of 25-53%. The active substances in the antiplasmodial test displayed IC50 values ranging from 0.68-2.89 mu M and 0.85-2.07 mu M against W2 and 3D7 strains, respectively.

Automated summary

Malaria has a significant impact on global health, and drug resistance is a major challenge in its treatment, highlighting the need for new antimalarial drugs. Through a key reaction catalyzed by Copper(I), 31 triazole compounds were successfully synthesized, with active substances showing promising antiplasmodial activity in the malaria test.