Publication Date:
2013-11-30
Description:
The reactivities towards DNA and protein of a benzimidazole derived mononuclear copper(II) complex, [Cu(EDTB)](NO 3 ) 2 · C 2 H 5 OH ( 1 ) [EDTB = N , N , N ′, N ′-tetrakis(2′-benzimidazolyl methyl)-1,2-ethanediamine], were investigated under physiological conditions using UV/Vis absorption, fluorescence, and circular dichroism (CD). The experimental results suggest complex 1 could strongly bind to calf thymus DNA (CT-DNA) and induce a remarkable conformational variation of DNA. The intrinsic binding constant K b of complex 1 to DNA is 1.08(± 0.02) × 10 5 M –1 and the apparent binding constant K app is 3.9 × 10 6 M –1 . The strong affinity was chiefly arising from intercalation of the benzimidazole aromatic rings of ligand system of 1 with the DNA base stack. Additionally, complex 1 could also interact with bovine serum albumin (BSA) and quench the intrinsic fluorescence of BSA. At higher concentration range of complex 1 (0–210 μM), the fluorescence quenching of BSA by complex 1 is a combined quenching (both dynamic and static) process; at lower concentration range of complex 1 (0–15 μM), the binding process is a single static mechanism with the binding constant ( K A ) ca. 10 5 M –1 . Further, cytotoxic activity of complex 1 in vitro was evaluated against the human cervical cancer (HeLa), human lung cancer (A-549), and human mammary cancer (MCF-7) cell lines. The results reveal complex 1 demonstrates a significant inhibition against the three cell lines with the IC 50 values falling in the 36.12–55.13 μM range.
Print ISSN:
0044-2313
Electronic ISSN:
1521-3749
Topics:
Chemistry and Pharmacology
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