Antibacterial and antifungal activities of nitroxoline Mannich bases

The in vitro activity of nitroxoline and its Mannich bases against bacteria and fungi was investigated. Nitroxoline and its derivative with diisopropylamine as an amino component, exhibited the highest antimicrobial activity. The optimum hydro/lipophilic properties (log P), both for antibacterial and antifungal activity, are about log P values of 2. The least effective compound was this nitroxoline Mannich base which has diethanolamine as an amino component.