Investigations into the Structure/Antibacterial Activity Relationships of Cyclam and Cyclen Derivatives.

A series of cyclam- and cyclen-derived salts are described in the present work; they were designed specifically to gain insights into their structure and antibacterial activity towards and , used respectively, as Gram-positive and Gram-negative model organisms. The newly synthesized compounds are monosubstituted and -disubstituted tetraazamacrocycles that display benzyl, methylbenzyl, trifluoromethylbenzyl, or trifluoroethylbenzyl substituents appended on the nitrogen atoms of the macrocyclic ring. The results obtained show that the chemical nature, polarity, and substitution patterns of the benzyl groups, as well as the number of pendant arms, are critical parameters for the antibacterial activity of the cyclam-based salts.