Relationship between antibacterial activity and constituents of Cryptomeria japonica essential oil

Abstract

Cryptomeria japonica (Sugi) is a plant native to Japan that has attracted considerable attention because of its varied biological activities. We focused on the antibacterial activity of C. japonica and investigated whether the activity of Sugi oil can be estimated based on its components. Sugi oil exhibited antibacterial activity against the gram-positive bacteria Staphylococcus aureus and Bacillus subtilis and gram-negative bacteria Escherichia coli. A difference in activity was observed between individual plants with different Sugi oil constituent ratios. The common component was a-pinen, and its content differed between samples. No correlation between content of a-pinen and the activity was observed. These results suggest it is difficult to estimate antibacterial activity from the content of the common major component. Minor components might play a role as an enhancer of antibacterial activity.