Ames test benzimidazole 2 nitrofluorene 4 (5,6 dimethyl 1h benzo[d]imidazol 2 yl) n' (2 hydro xybenzylidene)benzohydrazide 4 (5,6 dimethyl 1h benzo[d]imidazol 2 yl) n' (3 hydroxybenzylidene)benzohydrazide Activation, Metabolic Article Benzimidazole Benzimidazoles Drug Resistance, Microbial Genotype Mutagens Salmonella enterica serovar Typhimurium Salmonella typhimurium Structure-Activity Relationship Structure-activity relationship (SAR) animal tissue antibiotic resistance bacterial strain benzimidazole derivative chemical modification chemistry controlled study drug effect drug synthesis gene gene deletion genetic analysis genetics genotype