with the penetration of synthetic cationic surfactants into the environment and their high toxicity toward aquatic organisms , it becomes necessary to search for new, safer active ingredients with potent antimicrobial activity among compounds of natural origin. Therefore, the biological activity of the obtained quinine-based QASs against pathogenic foodborne microorganisms (L. monocytogenes), microbes responsible for opportunistic infections with serious consequences (e.g., S. aureus, P. aeruginosa, E. coli, C. albicans), as well as being pathogens of crop plants at all stages of their development (F.