Isolation And Purification Of Polyphenols From Dendrobium Huoshanense And The Effect On Probiotics And Pathogenic Bacteria

Dendrobium huoshanense was a valuable traditional Chinese medicine,it contains a lot of biologically active substances,such as polysaccharides,polyphenols,dendrobine,etc.A lot of research showed that polyphenols had a strong antioxidant effect,which could effectively remove excess active oxygen in the human body and slow down the aging of the body.In addition,D.huoshansense polyphenols had the functions of anti-inflammatory and anti-tumor,it could also regulate the human intestinal system and improve the growth status of intestinal floraThere were few reports on the probiotic and bacteriostatic effects of polyphenols.In this study,the extraction process of D.huoshansense polyphenols were investigated,and the macroporous resin was used to separate and purify D.huoshansense polyphenols.The antioxidant activity of polyphenols and its effects on probiotics and pathogenic bacteria were discussed.The results were as follows:1.Optimization of extraction conditions of polyphenols from D huoshansenseComparing the effects of different solvents on the extraction of polyphenols,it was found that the extraction of polyphenols with distilled water was higher than that of other organic solvents.After that,the time,temperature,material-liquid ratio and pH during the leaching process were investigated using a single-factor process optimization method.The best conditions for the extraction of polyphenols were as follows:the extraction time 50 min,extraction temperature 60℃,material-liquid ratio 1:70(g:mL)and extraction solution pH value 4.Under these conditions,the yield of D.huoshansense polyphenols reached 10.14 mg/g2.Macroporous resin purification of D.huoshansense polyphenolsThe AB-8 resin could be used as an adsorbent for D huoshansense polyphenols.The static adsorption reaches saturation after 150 min,the pH of the polyphenol solution was 4.0,the concentration was 2.0 mg/mL,the sample flow rate was 1.0 mL/min,the elution flow rate was 1.0 mL/min,and the purity of the total phenol was 76.2%Through gradient elution of ethanol solution,four elution components were obtained which named DHPoly-1,DHPoly-2,DHPoly-3 and DHPoly-4,respectively.3.Antioxidant,probiotic and antibacterial effects of D.huoshansense polyphenolsThe total antioxidant capacity of the four eluted components was investigated from four indexes:superoxide radical scavenging,ABTS scavenging,DPPH scavenging,and total reducing power.The results showed that the scavenging rates of superoxide anions by the four components were 59.05%,51.17%,68.79%,64.91%and the free radical scavenging rates of ABTS were 83.78%,77.52%,93.18%and 90.28%,respectively.The removal ability was strong,the total reducing power DHPoly-3>DHPoly-4>DHPoly-1>DHPoly-2,the removal rate of DPPH free radicals was weak and the difference was not significant,the total antioxidant capacity DHPoly-3>DHPoly-4>DHPoly-1>DHPoly-2.Judging and analyzing the inhibitory effect of Dendrobium huoshanense polyphenols components on pathogenic microorganisms through the determination of minimum inhibitory concentration(MIC)and bacteriostatic radius,When the concentration of DHPoly-3 component was 0.25 mg/mL and 0.125 mg/mL,it had inhibitory effect on E-coli and Bacillus subtilis,respectively,the bacteriostatic radius was 3.6 mm and 4.1 mm;The growth conditions of D.huoshansense polyphenols components added to the medium on probiotics were analyzed,and the differences between the components were compared.All four components had the effect of promoting probiotics and inhibiting the growth of pathogenic bacteria.Among them,the component DHPoly-3 had the best effect.