Abstract:As compared with steam distillation, the volatile oil from Zanthoxylum bungeanum Maxim. was extracted by supercritical CO2 extraction (SCE) and identified by GC-MS. Taking the yield of volatile oil as the evaluation index, the extraction process was optimized by response surface method. The experimental results showed that the essential oil yield was as high as 12.70% when the sample was extracted by the supercritical CO2 extraction method for 180 min at 42 ℃ and 30 MPa, which was 2.27 times as that obtained by steam distillation (SD). The chemical composition in the essential oils obtained by SCE and SD were similar but with very different contents analyzed by GC-MS. The main constituents were xanthoxylin (32.99%/10.56%), linalool (4.68%/4.84%), eucalyptol (3.92%/5.84%), α.-terpineol (4.55%/7.04%), terpinen-4-ol (2.95%/10.42%), terpinyl acetate (5.19%/7.24%), piperitone (5.40%/4.41%) and anethole(2.91%/3.73%). The relative contents of the components in the essential oils were determined with area normalization method. Among them, the relative content of xanthoxylin in the volatile oil obtained by SCE was the highest (32.99%). It showed that the extraction yield of the essential oil extracted by SCE was much higher, compared with traditional steam distillation. Moreover, the content of xanthoxylin, which is the characteristic chemical constituent of volatile oil from Zanthoxylum bungeanum Maxim., was very high. This is beneficial for the purification and manufacture of xanthoxylin. Our results provide a foundation for the development and utilization of volatile oil from Zanthoxylum bungeanum Maxim.
