响应面法优化超临界CO_2萃取决明子挥发油工艺及其抑菌活性研究

Optimization of supercritical carbon dioxide extraction conditions of Semen Cassiae volatile oil using response surface method and the research of its antimicrobial activity

目的：采用响应面法对超临界CO2萃取决明子挥发油的工艺进行优化,同时对提取所得决明子挥发油的抑制活性进行研究,对挥发油成分进行初步分析。方法：在单因素实验基础上,采用中心组合（BoxBehnken）实验设计,考察萃取压力、温度、时间对挥发油提取率的影响,采用响应面分析法对实验结果进行分析,同时采用纸片扩散法对提取所得挥发油抑菌效果进行考察,采用GC-MS法对挥发油成分进行分析。结果：超临界CO2萃取决明子挥发油的最优提取工艺：萃取温度51℃,萃取压力25 MPa,萃取时间3.22 h;在最优条件下,萃取率可达2.34%;抑菌活性研究结果表明,决明子挥发油对几种常见的细菌和真菌具有较好的抑菌活性,最低抑菌浓度（MIC）在2.5～5 mg·m L-1范围内。结论：超临界CO2萃取决明子挥发油工艺稳定,提取率较高,决明子挥发油具有明显的抑菌活性,为其在抑菌制剂中的应用提供了一定的理论依据。

Objective： To adopt the response surface analysis method to optimize the supercritical carbon dioxide extraction conditions of Semen Cassiae volatile oil;to study the antimicrobial activity of the extract from Semen Cassiae,as well as the components of the volatile oil.Methods：The Box-Benhken central composite design method was used based on the single factor experiments.The effects of the temperature,extraction time and on the yield were studied.The response surface method was employed to analyze the results of experiments.The disk diffusion method was used to detect the antimicrobial activity of Semen Cassiae volatile oil.GC-MS was used to analyze the volatile oil components.Results：The results indicated that the optimum extraction conditions were as follows：extraction temperature was at 51 ℃,extraction pressure was 25 MPa,extraction time was 3.22 h.The extraction yield reached 2.34%.The volatile oil of Semen Cassiae had antimicrobial activity of the tested strains,the MIC of the volatile oil ranged from 2.5 mg·m L-1 to 5 mg·m L-1.Conclusion：The supercritical carbon dioxide extraction is a stable and efficient process and the volatile oil of Semen Cassiae had antimicrobial activity.This study could provide certain theoretical basis for application of volatile oil.