Study On Antimicrobial And Antioxidant Activity Of Bidens Bipinnata Extracts

This subject mainly research on the bacteriostatic activity of Bidens bipinnataextracts, the effect of light, heat and pH stability on extracts, optimum extractionprocess conditions of antimicrobial active substances, Bidens bipinnata antibacterialactive site, active site main effective components and their contents. The antioxidantactivity and the extraction area of Bidens bipinnata extracts were also preliminarydiscussed. The main research contents were as follows:Bidens bipinnata water extract and alcohol extract on7kinds of antimicrobial byfilter method and the growth rate method were measured. The result showed thatBidens bipinnata alcohol extract has a wide antimicrobial spectrum and differentdegree antibacterial effect on staphylococcus aureus, bacillus subtilis, Candidaalbicans, Peronophythora litchii, Rhizoctonia solani. But it has no antibacterial effecton e. coli and Magnaporthe grisea.More Bidens bipinnata alcohol fetch the effects of the concentration ofantimicrobial results showed that the higher extract concentration, the moresignificant bacteriostatic effect,in the range of50mg/ml-800mg/ml. The sameconcentration of Bidens bipinnata herb extracts of different bacteria inhibition effectdifferences, bacteriostatic effect on bacillus subtilis than staphylococcus aureus. Twicein a test tube dilution method, measuring Bidens bipinnata alcohol extract ofminimum bacteriostatic concentration (MIC), the results showed that Bidensbipinnata alcohol extract of s. aureus minimum bacteriostatic concentration (MIC) is12.5mg/mL, the minimal inhibitory concentrations (MIC) of bacillus subtilis (MIC)is6.25mg/mL.On the basis of single factor experiment, orthogonal experiment design was used.The extraction process conditions of Bidens bipinnata herb were optimized. It hasconcluded that the best extract process conditions of antimicrobial active substanceswere:95%ethanol,70℃for2h, extraction times3.The results of light, heat and pH stability test on Bidens bipinnata alcoholextracts were that Bidens bipinnata alcohol extracts of ultraviolet light, good thermal stability, bacteriostatic effect stable pH4~8scope.All extracts obtained in different fractions by using systematic solvents werecompared through the testing of their antimicrobial activities. The results showed theextraction of ethyl acetate had a strong capacity on staphylococcus aureus andbacillus subtilis. The color reaction of reduction，metallic salts complexing and underultraviolet and visible light showed that the main actives of the extraction ofethylacetate were flavonoids. With Rutin being taken as the standard sample, thegression equation of rutin standard working curve was established．Total flavonoidscontent was determined by Spectrophotometry.The determination of Bidens bipinnataalcohol extract, ethyl acetate coherent paste flavonoids content were8.31%,9.93%respectively.Bidens bipinnata alcohol extracts by D-101macroporous resin after ethanolgradient elution,60%ethanol elution flavonoids content was highest at92.17%.Theelution content extract of staphylococcus aureus minimum bacteriostaticconcentration (MIC) was6.25mg/mL,the minimal inhibitory concentrations (MIC) ofbacillus subtilis (MIC) was3.125mg/mL, the bacteriostasis was greatly enhanced bymacroporous resin purification. Bidens bipinnata flavonoids were major antimicrobialsubstances.Antioxidant activity experiments were carried out for each alcohol extraction ofBidens bipinnata.The results showed that the ultra oxygen anion removal function ofpetroleum ether extract is the strongest,and it increased by68.9%compare with VC.The total reducing power, and the ability to remove hydroxyl free radical.OHand DPPH. free radical were evaluated.Then the result is that the antioxidant capacityof Bidens bipinnata n-butyl alcohol extraction is best among different polar extractioncomponents.At1mg/ml,the reducing power of Bidens bipinnata n-butyl alcoholextraction is72.9%of VC’s.The ability to remove DPPH. free radical is similar toVC,and it is about92.8%of VC’s.The ability to remove hydroxyl radical.OH is1.03times of VC’s. The bacteriostasis effect of Bidens bipinnata ethyl-acetate-extractionis best,and its ability to remove DPPH. free radical and hydroxyl radical.OH was strong. They are62.35%and70.6%of VC’s at the same concentration.In conclusion, the antibacterial activity and antioxidant capacity of Bidensbipinnata were good. It provides the experimental basis on using Bidens bipinnata asa new type of natural antiseptic and natural antioxidant. This promote more effectiveutilization of Bidens bipinnata resources.