Study of the antimicrobial and antioxidant action of oxo-derivatives of nitrogen-containing heterocycles and their acyclic analogues
We investigated antimicrobial and antioxidant activity of nitrogen-containing heterocycles and their acyclic analogues, some of which can be considered as promising in terms of biological activity. Based on structure, 26 tested compounds were divided into 4 groups. In the test with 2,2-diphenyl-1-picrylhydrazyl (DPPH), the compounds of the group 2 had the highest radical-binding activity (RBA) (53–78%), while those of group 3 had the lowest values (1.5–5.2%). In oxygen radical absorbance capacity assay, all compounds from groups 1, 2 and 3 showed high RBA: 44–94% at 50 μM. The highest bacteriostatic activity against Escherichia coli was found for four compounds in group 2 (MIC = 0.25–1 mM) and low bacteriostatic activity for group 3 (MIC > 4 mM). Some relationships between the structure
of compounds and the values of the MIC are revealed. It was
also found that four substances from different groups had the
ability to inhibit the formation of colonies in E. coli from
1.3 to 5.7 times. Four compounds reduced specific biofilm
formation by 40–60%. The tested substances did not induce the expression of the sulA gene controlled by the SOS system, which indicates the lack of genotoxic activity. None of the tested compounds had pro-oxidant activity. This was shown by both the absence of production hydrogen peroxide in a bacteria-free medium and inability to induce expression of the katG gene encoding HPI catalase in growing E. coli.
