Synthesis and biological activity of new potential antimalarial: 1H-pyrazolo[3,4-b]pyridine derivatives

The appearance of drug resistant Plasmodium falciparum malaria necessitates the search for novel antimalarial agents. Using the classical ring-bioisosterism concept as a strategy to develop new potential drugs, 1H-pyrazolo[3,4-b]pyridine 4-aminomethanol compounds were designed and synthesized as isosteres of the classical quinoline antimalarial mefloquine. The hydrochloride form of these compounds were tested for in vitro antimalarial activity against chloroquine-sensitive (Sierra Leone D-6) and resistant (Indochina W-2) clones of P. falciparum. The results described herein indicated that 1-H-pyrazolo[3,4-b]pyridine system represents a bioisosteric framework to quinoline system in the antimalarial activity.