Sun, B., Southam, H.M., Butler, J.A. et al. (5 more authors) (2018) Synthesis, isomerisation and biological properties of mononuclear ruthenium complexes containing the bis[4(4 '-methyl-2,2 '-bipyridyl)]-1,7-heptane ligand. Dalton Transactions, 47 (7). pp. 2422-2434. ISSN 1477-9226
Abstract
A series of mononuclear ruthenium(II) complexes containing the tetradentate ligand bis[4(4’-methyl-2,2’- bipyridyl)]-1,7-heptane have been synthesised and their biological properties examined. In the synthesis of the [Ru(phen’)(bb7)]2+ complexes (where phen’ = 1,10-phenanthroline and its 5-nitro-, 4,7-dimethyland 3,4,7,8-tetramethyl- derivatives), both the symmetric cis-α and non-symmetric cis-β isomers were formed. However, upon standing for a number of days (or more quickly under harsh conditions) the cis-β isomer converted to the more thermodynamically stable cis-α isomer. The minimum inhibitory concentrations (MIC) and the minimum bactericidal concentrations (MBC) of the ruthenium(II) complexes were determined against six strains of bacteria: Gram-positive Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA); and the Gram-negative Escherichia coli (E. coli) strains MG1655, APEC, UPEC and Pseudomonas aeruginosa (P. aeruginosa). The results showed that the [Ru(5-NO2phen)- (bb7)]2+ complex had little or no activity against any of the bacterial strains. By contrast, for the other cisα-[Ru(phen’)(bb7)]2+ complexes, the antimicrobial activity increased with the degree of methylation. In particular, the cis-α-[Ru(Me4phen)(bb7)]2+ complex showed excellent and uniform MIC activity against all bacteria. By contrast, the MBC values for the cis-α-[Ru(Me4phen)(bb7)]2+ complex varied considerably across the bacteria and even within S. aureus and E. coli strains. In order to gain an understanding of the relative antimicrobial activities, the DNA-binding affinity, cellular accumulation and water–octanol partition coefficients (log P) of the ruthenium complexes were determined. Interestingly, all the [Ru(phen’)- (bb7)]2+ complexes exhibited stronger DNA binding affinity (Ka ≈ 1 × 107 M−1 ) than the well-known DNAintercalating complex [Ru(phen)2(dppz)]2+ (where dppz = dipyrido[3,2-a:2’,3’-c]phenazine).
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > School of Biosciences (Sheffield) > Department of Molecular Biology and Biotechnology (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 21 Aug 2018 14:20 |
Last Modified: | 21 Aug 2018 14:20 |
Published Version: | https://doi.org/10.1039/c7dt04595f |
Status: | Published |
Publisher: | Royal Society of Chemistry |
Refereed: | Yes |
Identification Number: | 10.1039/c7dt04595f |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:134226 |