Synthesis and Antimalarial Activity of Ethyl 3-Amino-4-oxo-9- (phenylsubstituted)thieno[2,3-b]quinoline-2-carboxylate Derivatives.

Abstract

A series of thieno[2,3-b]quinolone derivatives were synthesized and investigated for their abilities to inhibit 􀀁-hematin formation, hemoglobin hydrolysis and in vivo for their efficacy in rodent Plasmodium berghei. Compound 3b was the most promising as inhibitor of hemoglobin hydrolysis, and its effects as inhibitor of 􀀁-hematin formation was promising. When the aromatic ring was substituted in 2 (Me), in 3 (CF3) or in 2,4 (Cl) the inhibition of hemoglobin proteolysis was maximal (88%), the rest of compounds maintained a low inhibition. The most active compound to emerge in vitro and in murine studies, was 3b suggesting an antimalarial activity via multiple mechanisms.