Synthesis and antimicrobial activity of new mono-and biquaternized dipyridylethanes and dipyridylethylenes

A series of mono-and biquaternized derivatives of dipyridylethane and dipyridylethylenes were synthesized in order to study their antimicrobial activity (AMA) with respect to Gram-negative ( E. coli ) and Gram-positive ( S. aureus ) species. It is established that the antimicrobial activity depends on the nature of the radical on the nitrogen atom, the positions of the ethane and ethylene bridges between the rings relative to the onium nitrogen atoms, and the presence of conjugated systems between these atoms. The maximum AMA with respect to the indicated test microbe strains was observed for 1-( N -dodecylpyridin-4-yl)-2-(4-pyridyl)ethylene bromide (MIC 3.9 and 2.0 μg/mL, respectively).