Activity of new quaternary ammonium salts in the SOS chromotest and in influencing the synthesis of biomacromolecules

Potential genotoxic effects of substances of a homologous series of 2-(10-undecenoyloxy)ethylalkyldimethylammonium bromides (n = 11, C-2-C-14) from the group of new ''soft'' quaternary ammonium salts were tested in the SOS-chromotest using a selected mutant E. coli PQ 37 strain containing sfiA::lacZ gene fusion. The genotoxic activity expressed by the induction factor (IF) values was the most pronounced in the substance with ethyl (C-2) (IF = 3.68 at the concentration of 25 mu g/ml), further in the substance with butyl (C-4) (IF = 2.66 at the concentration of 100 mu g/ml) and in the substance with hexyl (C-6) (IF = 2.11 at the concentration of 12.5 mu g/ml). Marginal genotoxicity was observed in the substance with octyl (C-8), which al the concentration of 6.25 mu g/ml had an IF of 1.72. The other substances of tile homologous series were unable to induce SOS functions. DNA damaging effects were tested in the absence of S9-mix. Additionally, no correlation was seen between the length of the alkyl chain and genotoxicity. By following up the incorporation rate of [C-14] precursors into S. typhimurium cells it was found that with substances with C-2-C-8 carbons primary interference with nucleic acids synthesis as indicated by IC50 adenine values occurred. The substance with hexyl (C-6) was the most effective.