The Medicinal Applications of Imidazolium Carbene-Metal Complexes

The medicinal applications of various transition metals-NHC complexes including silver, gold, rhodium, ruthenium, and palladium are reported. Pernak and co-workers examined a number of 3-alkylthiomethyl-l-ethylimidazolium chlorides. The antimicrobial activity was reported in terms of the minimum inhibitory concentration (MIC) values. A study done by Cetinkaya verified the effects of lipophilic substituents, anions, and backbone substituents on the antimicrobial activity associated with a series of 1,3- diazolidinium salts and the effect of ring size of pyrimidinium salts. One interesting trend observed among some metals such as ruthenium and silver is that each one utilizes multiple biological mechanisms and can work by a variety of different routes. The lipophilicity of NHCs and most of their metal complexes seems to be important in contributing to both their antimicrobial and antitumor effects. Silver NHCs is the most effective in terms of their antimicrobial activity and low toxicity compared with other antimicrobial metal-NHCs.