Preliminary Study on Antibacterial Activity of Benzyl Isothiocyanate and Its Analogues

In this research,the antimicrobial activity of benzyl isothiocyanate and its structural analogues(benzyl isocyanate,phenyl isothiocyanate,phenylethyl isothiocyanate,ethyl isothiocyanate)against E. coli and S. aureus were studied. Through the measure of bacteriostasis circle,minimum bacteriostasis concentration,minimum bactericidal concentration,growth curve,energy metabolism and structure-activity relationship,the bacteriostasis active group and bacteriostasis mechanism of benzyl isothiocyanate and its analogues were preliminarily explored. The results showed that,5 substances both had bacteriostatic effects on tested strains,and S. aureus was more sensitive. The antibacterial activity of benzyl isothiocyanate was attributed to the interaction of isothiocyanate group,methylene group and benzene ring,and the isothiocyanate group had the most decisive effect,followed by the methylene group and the benzene ring. The effects of different structural substances on the metabolic activity and related enzyme activities of bacteria were different. The isothiocyanate group had the greatest effect on energy metabolism and the substitution of oxygen atoms for sulfur atoms further enhanced this effect. The benzene ring had a reverse effect on energy metabolism. The antimicrobial activity of the substance which had the most significant inhibitor of energy metabolism was not the strongest,which indicated that other bacteriostasis mechanisms might exist.