Abstract

Four ternary complexes, [Cu(L1)2(bipy)] (1) [HL1 = N-(6-chlorobenzo[d]thiazol-2-yl)-4-methylbenzenesulfonamide], [Cu(L2)2(bipy)] (2) [HL2 = N-(benzo[d]thiazol-2-yl)-4-methylbenzenesulfonamide], [Cu(L3)2(bipy)]·1/2H2O (3) [HL3 = N-(5,6-dimethylbenzo[d]thiazol-2-yl)-4-methylbenzenesulfonamide] and [Cu(L4)2(bipy)] (4) [HL4 = N-(5,6-dimethylbenzo[d]thiazol-2-yl)benzenesulfonamide], were prepared and then characterized by X-ray crystallography, spectroscopy and magnetic measurements. Whereas the molecular structure of 1 and 2 consists of a discrete monomeric copper(II) species with a distorted square planar geometry, that of 3 and 4 consists of two independent molecules. In 3, both molecules present a different coordination geometry (distorted square planar and distorted square pyramidal) while in 4 they have an identical coordination environment (distorted square planar). The propensity for binding of 1-4 to calf thymus DNA was studied by thermal denaturation, viscosimetry, and fluorescence measurements. Results indicated that the N-sulfonamide derivative plays an important role in governing the type of interaction with DNA. The ability of the complexes to cleave DNA was studied in vitro with ascorbate activation and was tested by monitoring the expression of the yEGFP gene containing the RAD54 reporter. Moreover, their antiproliferative activity was verified in two cellular models: yeast and human tumor cells in culture. Their DNA cleavage efficiency at the cellular level was found to be: 1 < 3 ~ 4 < 2. The higher propensity of 2 for inflicting DNA damage was related with its higher binding affinity to DNA. The biological studies carried out with human tumor cells, colon adenocarcinoma Caco-2 cells and leukemia Jurkat T lymphocytes confirmed that the compounds produce cell death mainly by apoptosis, the complex 2 being the most effective.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.