Bethoxazin(Bethoguard) is a new broad spectrum industrial microbicide with applications in material and coating preservation. IC50 value: Target: Microbicide Bethoxazin potently inhibited the catalytic activity of yeast DNA topoisomerase II and the growth of yeast BY4742 cells at low micromolar concentrations. bethoxazin may exert its microbicidal action by reacting with sensitive endogenous sulfhydryl biomolecules of microbial cells.