Studies On Extraction And Purification Of Celery Flavonoids And Its Antioxidant Activity

As a class of plant constituents with effects of antioxidant and antibacterial, flavonoids also proved to be a bioactive natural component with anti-tumor activity. In this paper, flavoniods were extracted from celery and the processing conditions were optimized. Then, flavonoids were purified by macroporous resin and the antioxidant ability was studied with radical scavenging rate of DPPH. Detailed experimental results were as follows:(1) Flavonoids content was measured by spectro photometry (Lutin as standard). Based on the Soxhlet extraction results, we selected the best extraction conditions for agitation method from the results of orthogonal experiments:ethanol concentration60%, solid liquid ratio1:45, water base heating temperature at80℃for4hours and extracting for twice. Flavonoids content of celery gained in different seasons was different, and flavonoids content order in different parts of celery was leaf> root> stem.(2) Compared the static adsorption and static desorption results of flavonoids on HZ818&HZ830macroporous resin, chose HZ830macroporous resin to do the dynamic adsorption experiments. Ethanol gradient elution chromatography was applied, and the results showed that flavonoids content order of enrichment in different ethanol elution section was60%ethanol elution section>40%ethanol elution section> anhydrous ethanol elution section>20%ethanol elution section>80%ethanol elution section. Discussed static adsorption on HZ830macroporous resin under different oscillating conditions, and studied the adsorption of flavonoids on HZ830macroporous resin at different temperature with Langmuir equation and Kannan diffusion model in oscillating environment.(3) Antioxidant ability of flavonoids was determined by DPPH radical scavenging ability, and antioxidant ability order of celery flavonoids in different parts was stem> leave> root when at the same concentration. Flavonoids antioxidant ability of celery gained in different seasons were similar. Compared the antioxidant capacity of0-20%and20%-60%ethanol elution section after the dynamic adsorption experiments with HZ830macroporous adsorption resin, we found that the antioxidant ability of flavonoids from celery leaf was stronger than flavonoids from celery stem. Antioxidant ability order of flavonoids enriched from different ethanol elution section was anhydrous ethanol elution section>20%ethanol elution section>60%ethanol elution section-40%ethanol elution section>80%ethanol elution section. According to the HPLC analysis,20%elution section contained a lot of polar flavonoids which were more difficult to separate, while anhydrous ethanol elution section was with more alcohol-soluble components such as apigenin and it may eventually lead to the strong antioxidant activity than20%ethanol eluted section.