Evaluation of Antibacterial Activity of 3‐Butenyl, 4‐Pentenyl, 2‐Phenylethyl, and Benzyl Isothiocyanate in Brassica Vegetables

Abstract: This study investigated antibacterial activities of 4 isothiocyanates (3‐butenyl, 4‐phentenyl, 2‐phenylethyl, and benzyl isothiocyanate) against 4 Gram‐positive bacteria ( Bacillus cereus , Bacillus subtilis , Listeria monocytogenes , and Staphylococcus aureus ) and 7 Gram‐negative bacteria ( Aeromonas hydrophila , Pseudomonas aeruginosa , Salmonella choleaesuis , Salmonella enterica , Serratia marcescens , Shigella sonnei , and Vibrio parahaemolyticus ) by an agar disc diffusion assay. Benzyl isothiocyanate (> 90.00 mm inhibition zone diameter at 0.1 μL/mL) and 2‐phenylethyl isothiocyanate (58.33 mm at 0.2 μL/mL) showed large inhibition zones especially against B . cereus . Also, 3‐butenyl isothiocyanate (21.67 mm at 1.0 μL/mL) and 4‐pentenyl isothiocyanate (19.67 mm at 1.0 μL/mL) displayed potent antibacterial activity against A. hydrophila . Benzyl and 2‐phenylethyl isothiocyanate indicated higher activity against most of the pathogenic bacteria than 3‐butenyl and 4‐pentenyl isothiocyanate, and were more effective against Gram‐positive bacteria than Gram‐negative bacteria.