Synthesis, antiproliferative and antitrypanosomal activities, and DNA binding of novel 6-amidino-2-arylbenzothiazoles.

A series of 6-amidinobenzothiazoles, linked via phenoxymethylene or directly to the 1,2,3-triazole ring with a -substituted phenyl or benzyl moiety, were synthesised and evaluated against four human tumour cell lines and the protozoan parasite . The influence of the type of amidino substituent and phenoxymethylene linker on antiproliferative and antitrypanosomal activities was observed, showing that the imidazoline moiety had a major impact on both activities. Benzothiazole imidazoline , which was directly connected to -1-phenyl-1,2,3-triazole, had the most potent growth-inhibitory effect (IC = 0.25 µM) on colorectal adenocarcinoma (SW620), while benzothiazole imidazoline , containing a phenoxymethylene linker, exhibited the best antitrypanosomal potency (IC = 0.12 µM). DNA binding assays showed a non-covalent interaction of 6-amidinobenzothiazole ligands, indicating both minor groove binding and intercalation modes of DNA interaction. Our findings encourage further development of novel structurally related 6-amidino-2-arylbenzothiazoles to obtain more selective anticancer and anti-HAT agents.