| In this study,polyphenols were extracted from Empetrum nigrum aerial parts(stems and leaves)by complex enzyme-assisted ultrasonic method,and the crude extract of polyphenols was enriched and purified by macroporous adsorption resin method.The specific structures of polyphenols were identified by LC-MS/MS technique.In addition,the antioxidant and antibacterial activities of crude extract and purified product were studied.In this paper,an efficient,green and economical extraction and enrichment process of polyphenols was developed,which provides theoretical support and scientific reference for the rational development and utilization of polyphenols from Empetrum nigrum aerial parts resources.The specific research results are as follows:1.The complex enzyme-assisted ultrasonic method were used.On the basis of single factor experiment and Fractional factorial design.Through the response surface method to get the best extraction technology conditions for:The temperature was 38.39?,the culture time was 3.39 h,the tannase content was 386.53 U/g and the cellulase content was 224.42 U/g.Under these conditions,the extraction yield was 52.3 1 mg/g.2.The crude polyphenols were purified by macroporous adsorption resin method.Moisture content,adsorption rate and desorption rate were investigated to determine the experimental resin was HPD-600.The response surface method was used to analyze the optimal process and the optimal extraction conditions were as follows:sample concentration was 0.84 mg/mL;ethanol concentration was 62.15%;elution flow rate was 0.67 mL/min;elution volume was 2.71 BV.Under these conditions,the extraction yield was 229.18 mg/g,the purity of polyphenols was increased from 8.11%to 22.56%,and the recovery rate was 67.78%.3.LC-MS/MS technology was used to analyze and identify the structure of polyphenols from Empetrum nigrum aerial parts.The result showed that there are 10 kinds of polyphenols in Empetrum nigrum aerial parts:Neochlorogenic acid,Catechin,Rutin,Hyperoside,Guavate,quercetin,4 '-methoxy-2'-hydroxyl dihydrochalone,2',4'-dihydroxyl dihydrochalone,7'-hydroxyl dihydroflavone,2',4 '-dihydroxyl-methoxy-3',4 '-dimethyl chalone.4.With Vc as the positive control,the antioxidant activity of crude extract and purified product was tested by DPPH assay with IC50 values of 212.919 and 165.435 ?g/mL,ABTS assay with IC50 values of 182.242 and 43.555 ?g/mL,FRAP assay with 3.272 and 4.671 mmol/L when the concentration was 500 ?g/mL.The results showed that it was found that both the crude extract and the purified product had strong antioxidant activity.On the whole,the antioxidant activity of the purified product was better than crude extract.Three Gram-positive bacterias(Staphylococcus aureus,Bacillus subtilis,Candida albicans)and three Gram-negative bacterias(Escherichia coli,Acinetobacter baumannii,Pseudomonas aeruginosa)were were tested by agar well diffusion method to evaluate the antibacterial activity of the extracts.The results showed that both the crude extract and the purified product had good antibacterial effect.In addition,the antibacterial effect of purified product was significantly stronger than crude extract,and the antibacterial effect of the extract against Gram-positive bacteria was stronger than Gram-negative bacteria.In summary,this study developed a new process for extraction of polyphenols from Empetrum nigrum aerial parts and obtained the purification process by using macroporous adsorption resin method.Ten kinds of polyphenolic compounds were identified.It was determined that the extract of polyphenols had good biological activity.This paper has an important theoretical reference value for the efficient extraction and enrichment of the effective components of Empetrum nigrum,and provides the necessary scientific support for its rational development and utilization. |
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