| Abstract |
Nootkatone is one of the sesquiterpenes contained in citrus peels, especially in grapefruits. It is known that nootkatone has various physiological activities such as antioxidative and antifibrotic actions. This study showed that nootkatone, a natural sesquiterpene, exhibited antibacterial activities against Gram-positive bacteria such as Staphylococcus aureus, Enterococcus faecalis, Listeria monocytogenes, Corynebacterium diphtheriae, and Bacillus cereus, with the antibacterial effect against C. diphthe- riae being most pronounced. However, no growth-inhibitory effects or bactericidal activity was observed against Gram- negative bacteria. In addition, the bactericidal activity of nootkatone at a high concentration was observed against Gram-positive bacilli. These results suggested that nootkatone may exert an antibacterial effect by targeting cell wall struc- tures or a particular metabolite. Moreover, even at a low concentration (0.25 mM), nootkatone was capable of inhibiting biofilm formation by Staphylococcus aureus. Thus, this study demonstrated antibacterial efficacy for nootkatone against Gram- positive bacteria, indicating that nootkatone could be a potential candidate for the development of new antibacterial agents.
|
