New thiophene–acridine compounds: Synthesis, antileishmanial activity, DNA binding, chemometric, and molecular docking studies

In this study, we synthesized eight new compounds containing the 2‐amino‐cycloalkyl[b]thiophene and acridine moieties (ACT01 and ACS01‐ACS07). None tested compounds presented human erythrocyte cytotoxicity. The new compounds presented antipromastigote activity, where ACS01 and ACS02 derivatives presented significant antileishmanial activity, with better performance than the reference drugs (tri and pentavalent antimonials), with respective IC50 values of 9.60 ± 3.19 and 10.95 ± 3.96 μm. Additionally, these two derivatives were effective against antimony‐resistant Leishmania (Leishmania) amazonensis strains. In addition, binding and fragmentation DNA assays were performed. It was observed that the antileishmanial activity of ACS01 is not associated with DNA fragmentation of the promastigote forms. However, it interacted with DNA with a binding constant of 104 m−1. In partial least‐squares studies, it was observed that the most active compounds (ACS01 and ACS02) showed lower values of amphiphilic moment descriptor, but there was a correlation between the lipophilicity of the molecules and antileishmanial activity. Furthermore, the docking molecular studies showed interactions between thiophene–acridine derivatives and the active site of pyruvate kinase enzyme with the major contribution of asparagine 152 residue for the interaction with thiophene moiety. Thus, the results suggested that the new thiophene–acridine derivatives are promising molecules as potential drug candidates. The new compounds presented antileishmanial activity, with better performance than the reference drugs (ACS01 and ACS02), without to present human erythrocyte cytotoxicity. The best compound ACS01 interacted with DNA. However, the antileishmanial activity of ACS01 is not associated with DNA fragmentation of the promastigote forms. Theoretical studies showed lower values of amphiphilic moment descriptor, but there was a correlation between the lipophilicity of the molecules and antileishmanial activity. In addition, the docking molecular studies showed interactions between thiophene–acridine derivatives and the active site of pyruvate kinase enzyme.