Chemical compositions and antibacterial activities of volatile oils from Taxodium ascendens leaves and cones

Objective To analyze and identify the chemical compositions of volatile oils extracted from Taxodium ascendens leaves and cones, and test the inhibition activities against seven different bacteria.

Method The volatile oils were extracted by hydro-distillation from the leaves and cones of Taxodium as-cendens and the chemical compositions of the essential oils were analyzed by GC-MS. The inhibitory ac-tivities against bacteria were tested using the filter paper diffusion method.

Result The yield rates for the essential oils of fresh leaves and cones were 0.211% (w) and 0.657% (w), respectively. Totally 21 components were identified from the volatile oil of leaves, which accounted for 90.410% of the total volatile content. (1R)-α-pinene (70.149%), (-)-α-terpineol (7.072%), 4-carene (2.025%) and β-pinene(2.012%) were the major compounds in the volatile oil of leaves. Totally 13 components were identified from the volatile oil of cones, which accounted for 95.285% of the total volatile content. (1R)-α-pinene (78.609%), ferruginol (4.276%), 4-carene (3.355%), limonene (2.324%) and β-terpinene (2.179%) were the major compounds in the volatile oil of cones. There were only four com-mon components in the volatile oils of both leaves and cones including (1R)-α-pinene, 4-carene, limonene and borneol. The volatile oil of cones showed the strongest inhibitory activity against Agrobacterium tumefaciens and the inhibition zone diameter was (34.5±2.3) mm, while the volatile oil of leaves showed the strongest inhibitory activity against Staphylococcus haemolyticus and the inhibition zone diameter was (16.0±1.2) mm.

Conclusion The content of volatile oil in T. ascendens cones is higher than that in leaves, and (1R)-α-pinene is the main ingredient in both. The volatile oil of cones has higher antibacterial activity than that of leaves.