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(I) complex, [CuI(2,2′-biquinoline)P(CH2N(CH2CH2)2O)3] (1bq), was synthesized and characterized by means of 1H, 13C{1H} and 31P{1H} 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)2O)3] (1N). 1bq also showed significantly lower cytotoxicity than 1N 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 1N and 1bq for DNA cleavage.

Graphical abstractA novel water and air stable copper(I) complex, [CuI(2,2′-biquinoline)P(CH2N(CH2CH2)2O)3], has been synthesized. The antibacterial and antifungal activity of this complex is lower than that of [CuI(2,9-dimethyl-1,10-phenanthroline)P(CH2N(CH2CH2)2O)3]. It also shows significantly lower cytotoxicity on mesenchymal stem cells culture and the RK-13 cell line. Both complexes bind to the HSA and BSA albumins in site I located in subdomain IIA.Figure optionsDownload full-size imageDownload as PowerPoint slide