engleski

Interactions of benzothiazole amidine derivatives with DNA

Benzothiazoles, a group of compounds containing a benzene ring fused with a thiazole ring, are used as therapeutic compounds with a wide range of biological and potential antitumor activities [1, 2]. Their biological activity and binding to DNA can be greatly improved with some substituents, such as amidines, at the end of heteroaromatic substructures [3]. Binding of studied compounds to calf thymus-DNA was monitored with fluorescence spectroscopy. From these data, stability constants of the formed complexes were determined. Titrations with ctDNA yielded fluorescence quenching of all studied compounds. For determination of the binding modes, CD titrations and Tm experiments were used. All compounds showed small or negligible stabilization effect of ctDNA, while some of them (A2, B3 and B4) showed great stabilization effect of AT-DNA. Compounds A4 and B4 exhibited positive induced CD spectra (ICD) with ctDNA which strongly suggests the minor groove binding to DNA. Addition of compound A2 to the ctDNA solution resulted in the appearance of a bisignate signal. Such change suggests the binding of the compound in the form of a dimer within the minor groove.

Benzothiazoles ; DNA ; Fluorescence spectroscopy ; minor groove binding

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