Volatile compounds and antimicrobial and antioxidant activities of the essential oils of the needles of Pinus densiflora and Pinus thunbergii.

BACKGROUND

To investigate the volatile compounds and the antibacterial and antioxidant effects of the essential oils of Pinus densiflora needles (EPDN) and Pinus thunbergii needles (EPTN), the volatile compounds of steam-distilled essential oils were analysed by gas chromatography-mass spectrometry. Antibacterial activities were analysed by performing disc-agar diffusion assay and determining the minimum inhibitory concentrations (MICs) of the essential oils. Antioxidant activities were analysed via radical- and nitrite-scavenging activity assays.

RESULTS

The yields of EPDN and EPTN were 0.304% (v/w) and 0.296% (v/w), respectively. In the antibacterial activity assay, the MICs of EPDN and EPTN for Klebsiella pneumoniae, Shigella flexneri and Proteus vulgaris were < 0.4 mg mL(-1) . In the antioxidant activity assay, the 50% inhibitory concentrations (IC(50) ) of EPDN and EPTN were 120 and 30 µg mL(-1) , respectively. At 1680 µg mL(-1) , both EPDN and EPTN exhibited > 50% nitrite-scavenging activity.

CONCLUSIONS

EPDN can be used as a natural antimicrobial substance.