The antimicrobial activities of 60 naturally occurring and synthetic quinolines were studied. The quinolines were organised into seven structural subgroups and, using an in-house microtitre assay, were tested against a range of Gram-positive and Gram-negative bacteria, including a hospital isolate of meticillin-resistant Staphylococcus aureus (MRSA). The quinolines exhibiting good bioactivity [i.e. low minimum inhibitory concentration (MIC)] against two S. aureus strains were then assessed for their antimicrobial activity against a range of eight clinically isolated MRSA strains. The study showed that 30 of the tested compounds displayed antimicrobial activity, mostly against Gram-positive bacteria. The effects of substituent groups on the bioactivity of these quinolines have also been discussed. The quinoline 4-hydroxy-3-iodo-quinol-2-one (11) exhibited significant antimicrobial activity, being active against the MRSA clinical isolates with MIC values comparable with the antibiotic vancomycin used in the treatment of MRSA infections. In particular, 4-hydroxy-3-iodo-quinol-2-one (11) showed MIC values of 0.097 mu g/mL against an Irish hospital MRSA-1 strain and 0.049 mu g/mL against a distinct MRSA strain as well as a non-typeable MRSA strain. (c) 2009 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.
O'Donnell, F., Smyth, T. J. P., Ramachandran, V. N., & Smyth, F. (2010). A study of the antimicrobial activity of selected synthetic and naturally occurring quinolines. International Journal of Antimicrobial Agents, 35(1), 30-38. https://doi.org/10.1016/j.ijantimicag.2009.06.031