Study On Extraction,Purification And Biological Activities Of Phenolic Compounds From Sonchus Arvensis L.Leaves

In this experiment,a simple and rapid method for extracting total phenols from leaves of Sonchus arvensis L.was established.The extraction of the leaves of Sonchus arvensis L.by ethanol negative pressure cavitation-assisted extraction,and the extracts were separated and purified by macroporous adsorption resin.The purified products were assayed for antioxidant,anti-inflammatory and antibacterial effects.The results were as follows:1.A method for simultaneous analysis of chlorogenic acid,cichoric acid and cynaroside in Sonchus arvensis L.leaves was established by HPLC.Column:Diamonsil Cis column;mobile phase:0.3%phosphoric acid aqueous solution(A)-methanol(B);column temperature 30?;detection wavelength 330 nm;flow rate 1 mL/min;Injection volume 20 ?L;gradient elution conditions:0 to 15 min,10%to 25%B;15 to 35 min,25%to 35%B;35 to 50 min,40%B;flow rate:1.0 mL/min.2.The experimental design and optimization of process parameters for the extraction of total phenols in the leaves of Sonchus arvensis L.by ethanol negative pressure cavitation-assisted extraction were carried out,and the optimal extraction parameters were determined:Extraction solvent:ethanolEthanol concentration:50%Extraction time:15 minLiquid to solid ratio:30:1 mL/gNegative pressure value:-0.08 MPaUnder the above optimized process parameters,the extraction rate of total phenols were 102.1 mg/g.3.Through the experimental research,the best process for the enrichment and purification of macroporous adsorption resin was determined.From the final result,AB-8 macroporous adsorption resin is the best for enriching and purifying the total phenol of Sonchus arvensis L.leaves.The purification conditions of total phenols were optimized,and the conditions of loading concentration,loading rate,ethanol concentration and ethanol elution rate were optimized to obtain the best experimental method for purifying the leafy phenolic compounds.According to the above optimal macroporous adsorption resin purification conditions,the purity of the total phenols in the leaves of the Sonchus arvensis L.leaves waere 3.75 times higher than that before the purification.4.The anti-oxidation,anti-inflammatory and antibacterial activities were studied in the purified polyphenols obtained by the three extraction methods.DPPH free radical scavenging rate:The scavenging ability of VC reference substance is significantly higher than that of the other three groups.The scavenging ability of ethanol-NPCE is greater than that of ethanol-UAE and ethanol-MAE.IC50 of four experimental groups.Values were:0.0628,0.252,0.314,0.321 mg/mL.FRAP reduction ability:VC control substance has the strongest reducing ability,followed by ethanol-NPCE and ethanol-UAE,and the worst effect is ethanol-MAE.The ability to remove ABTS+is:VC>ethanol-NPCE>ethanol-UAE>ethanol-MAE.The anti-inflammatory activity experiment mainly measured the cell viability of the leafy phenolic compounds obtained from the three extraction methods by MTT method.The concentration of the phenolic compounds in the leaves of the leeks was found to be in the range of 12.5-200 ?g/mL.There is no effect on the viability of RAW264.7 cells.Therefore,it can be shown that the stearyl compound leaves have no toxicity hazard to the cells in this concentration range.However,when the concentration of phenolic compounds reached 200?g/mL,the effect of inhibiting NO secretion was observed.In comparison,the extract obtained by ethanol-NPCE showed better inhibition of NO secretion than the other two extraction methods.The antibacterial activity experiment mainly determined the inhibition zone size and the minimum inhibitory concentration of the phenolic compounds of the chicory leaves on the five tested bacteria.The experimental results showed that the buds of the phenolic compounds reached 250 mg/mL.The inhibition zone diameters of Bacillus,Staphylococcus aureus,Pseudomonas aeruginosa,Candida albicans and Escherichia coli were 15.62 mm,15.01 mm,14.48 mm,12.31 mm,10.66 mm,respectively,and the minimum inhibitory concentration was 95 mg./mL,110 mg/mL,120 mg/mL,130 mg/mL and 145 mg/mL.From the experimental data analysis,the phenolic compounds of the leeks have a certain antibacterial activity.