Antibacterial Properties of Tetraalkylammonium and Imidazolium Tetraalkoxycalix[4]arene Derivatives

The antibacterial and antibiofilm activities of several amphiphillic tetracationic calixarenes with different functional groups were evaluated. Our results demonstrate the clear dependence of antibacterial activity from the alkyl chain length on the lower rim of calixarene. Tetrapropoxycalixarenes have 10-50 times higher antibacterial activity than tetraoctyl calixarenes with same cationic residues on the upper rim. At the same time, one of the tetrapropoxycalixarenes shows high inhibitory activity against Staphylococcus aureus biofilms. Therefore, the alkyl chain length is an important characteristic that can be used for further antibacterial agent design.