A novel copper(I) complex, [CuI(2,2′-biquinoline)P(CH2N(CH2CH2)2O)3] - Synthesis, characterisation and comparative studies on biological activity

A novel water and air stable copper(l) complex, [CuI(2,2'-biquinoline)P(CH2N(CH2CH2)(2)O)(3)] (1bq), was synthesized and characterized by means of H-1, C-13{H-1) and P-31{H-1} NMR, ESI-MS and elemental analysis. The X-ray structure of 1bq shows that the coordination geometry about the Cu(I) center is pseudo-tetrahedral. 1bq was assayed for antibacterial (Escherichia coli - a Gram-negative rod and Staphylococcus aureus - a Gram-positive coccus) and antifungal (Candida albicans) activities. The activity of 1bq was lower than that of [CuI(2,9-dimethyl-1,10-phenanthroline)P(CH2N(CH2CH2)(2)O)(3)] (1N). 1bq also showed significantly lower cytotoxicity than IN on MSC (mesenchymal stem cells) culture and the RK-13 cell line. Both 1bq and 1N complexes bind to HSA and BSA albumins in site I located in subdomain IIA, however 1bq interacts less strongly with these albumins than 1N. Surprisingly, investigation of the interactions of the studied complexes with pUC18 plasmid showed a comparable effectiveness of IN and 1bq for DNA cleavage. (C) 2012 Elsevier Ltd. All rights reserved.