The chemical composition, antioxidative and antimicrobial potentials of Toona sinensis essential oils from different regions of China

Toona sinensis is one of the traditional Chinese medicinal materials with rich physiological activities. This study aimed to investigate the chemical composition differences of the essential oils from the tender leaves and shoots of T. sinensis, collected from four main producing areas in China, and to verify their anti-listeria and antioxidant properties. Gas chromatography-mass spectrometry (GC-MS) analysis was conducted on the essential oils obtained by hydro-distillation. The results indicated that compounds such as beta-elemene (3.5 similar to 8.1%), alpha-caryophyllene (3.7 similar to 7.2%), and trans-caryophyllene (4.0 similar to 9.7%) were the main common components of T. sinensis essential oils (TSEO) from four producing areas. The results of DPPH and ABTS showed that the essential oil from Dazhou, Sichuan, China had the best antioxidant effect. At a concentration of 1.25 mg/mL, the antioxidant activity of TSEO-DZ from Sichuan was comparable to 0.08 mg/mL of BHT and was only slightly lower than 0.06 mg/mL of VC. The broth dilution method showed that the essential oil from Tai 'an, Shandong, China, showed better antibacterial effect, with the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MLC) values of 1.25 mu L/mL and 2.54 mu L/mL, respectively. This study demonstrates that TSEO possesses promising application potential in antioxidant and anti-listeria activities, and it confirms that the growth environment of T. sinensis significantly influences the quality, content, and biological activity of the essential oil.