Extraction Purification And Antibacterial Antioxidant Effect Of Chlorogenic Acid From Gynura Procumbens

Gynura procumbens (Lour.) Merr(GPM) is a kind of medicinal plants with several functions, such as anti-inflammatory, antihypertensive and hypoglycemic action. Chlorogenic acid (CGA) is one of the most important functional components in GPM. In the present study, the extraction and purification process of CGA from GPM were optimized. Also, the antioxidation and antimicrobial activities of different GPM extracts and CGA were investigated. The results were showed as follow:(1) The ultrasonic assisted extraction conditions of CGA from GPM were investigated by single-factor experiments and orthogonal experiment. The optimum conditions were with70%ethanol at pH2, solid to liquid ratio at1:15, extraction time of50min. Under the conditions, the average yield of CGA from GPM was3.13%.(2) HPD600was selected as optimal resin from eight kinds of resins by static adsorption test. The adsorption-elution conditions were further investigated by dynamic adsorption test. The optimum conditions conditions were as follows:the sample flow rate was2mL/min; the pH was3.0, the concentration of CGA in sample was3.45mg/mL, the volume of sample was7BV. CGA was eluted by30%ethanol with purity of87.47%. After purifing by semi-preparative HPLC, the CGA product was further identified by HPLC,1H NMR and13C NMR.(3) The antibacterial activity of CGA and different extractions of GPM to Saccharomyces cerevisiae, Staphylococuus aureus, Salmonella, Escherichia coli and Aspergilus niger were studied. In the five strains, CGA and all GPM extracts have obvious inhibition effects on bacteria, but with weak effects on yeast and mildew. The antibacterial circle diameter of CGA to Staphylococuus aureus was24.9mm at80mg/ml. The antibacterial activety order of different extracts was:ethylacetate extract> water extract> petroleumether extract> chloroform extract.(4) The antioxidant properties of CGA and different GPM extracts were investigated by different tests, including lipid peroxides inhibition, total reduction capacities and DPPH scavenging capacities. Compared with Vc, CGA showed stronger total reduction capacities and lipid peroxides inhibition activities, while possessed weaker DPPH scavenging capacities. All GPM extracts showed antioxidant activity. So GPM is a potential antioxidant plant.