Catechol‐ and Phenol‐Containing Thio‐Schiff Bases: Synthesis, Electrochemical Properties and Biological Evaluation

A number of novel catechol‐ and phenol‐containing Schiff bases with thiophenol or mercaptobenzimidazole groups have been synthesized. Electrochemical studies of the target compounds were carried out in order to establish the primary centres involved in redox reactions, and the mechanism of oxidative transformations. The antioxidant activities of the compounds were determined using different assays. Compounds combining the catechol group with the mercaptobenzimidazole or benzothiazoline cycles exhibit more pronounced antioxidant activity in the concerning tests. However, a significant promoting effect on the process of lipid peroxidation of rat brain homogenates was found in the presence of catechols. Antibacterial and cytotoxic effects of Schiff bases can be caused by the possibility of ROS and o‐benzoquinones generation. It was established that some compounds have a moderate bacteriostatic effect against Staphylococcus aureus strains. Schiff bases with catechol and heterocyclic groups exhibit a good antiproliferative activity (IC₅₀<10 μM) towards MCF‐7, HTC‐116 and A549 cell lines.