Antioxidative and antiproliferative activities of novel pyrido[1,2-<Emphasis Type="Italic">a</Emphasis>]benzimidazoles

A series of pyrido1,2-a]benzimidazoles has been designed, and novel examples are synthesized and evaluated for their potential antiproliferative activity against four human tumour cell lines—cervical (HeLa), colorectal (SW620), breast (MCF-7) and hepatocellular carcinoma (HepG2). In addition, their antioxidative potency has been evaluated by in vitro spectrophotometric assays. Preliminary structure–activity relationships among the synthesized compounds are discussed. Evaluation of their antioxidative capacity has shown that two compounds (25 and 26) possess promising reducing characteristics and free radical scavenging activity. Selective antiproliferative effect in the single-digit micromolar range was observed for compound 25 on MCF-7 \((\hbox {IC}_{50} = 6\,{\upmu }\hbox {M})\) and HeLa \((\hbox {IC}_{50} = 8\,{\upmu }\hbox {M})\) cell lines, comparable to the standards 5-fluorouracil and cisplatin. The combination of the radical scavenging activity and antiproliferative activity of compound 25 positions this compound as a potential lead candidate for further optimization.