Investigation On The Activities Of Antioxidant And Antibacterial Of Eucommia Male Flower

This paper, took Eucommia male flower as material, antioxidant activities, antibactericalactivities and Eucommia male flower polysaccharides as main aim, studied Eucommia maleflower. The male flowers of Eucommia ulmoides were extracted by the solvents with differentpolarities, namely, petroleum ether, ethyl acetate, n-butanol, and water. The contents of totalphenols in the obtained extracts were measured, and their antioxidant activities wereexamined in vitro and compared with those of BHT and VC, which were the two conventionalreductants, from the aspects of scavenging rate of DPPH and hydroxyl free radicals, reducingpower, and anti-lipid per-oxidation activity, respectively. Using Bacillus thuringiensis,Bacillus cereus Franklandand Frankland, Escherichia coli, Bacillus subtilis, Staphyloccocusaureus, Aerobacter aerogenes, Aspergillus Niger, Aspergillus oryzae, Rhizopus oligosporus,Saccharomyces cerevisiae as tested microorganism, The aim of the study is to investigate theantimicrobial activity of Eucommia male flower extracts in vitro. Using extractiontemperature, extraction time and solid to liquid ratio as factors that affect yield ofpolysaccharides from Eucommia male flower, A15-run Box-Behnken design was used tooptimize the extraction conditions of polysaccharides from Eucommia male flowers. Themain results are listed as follows.1. The results indicated that Eucommia male flower was rich in phenols. The content ofphenols in ethyl acetate extract （EE）(393.47mg·g^-1) and n-butanol extract （BE）(287.33mg·g^-1) were higher than those in water extract （WE）(114.74mg·g^-1) and petroleum extract（PE）(105.42mg·g^-1). The rates of scavenging DPPH free radical of the EE and BE were91.55%and80.32%, respectively, close to those of BHT and VC. The rate of scavenginghydroxyl free radical of BE was relatively higher （80.47%）, while the reducing power of EEwas higher than those of BHT and VC. The activities of anti-lipid per-oxidation of EE, BEand WE were higher than that of VC. The reducing power, rate of scavenging DPPH freeradical and activity of anti-lipid per-oxidation of the extracts were positively correlated to thecontent of total phenols （R²＞0.9）, and exhibited significant concentration dependent effect.The relatively higher antioxidant activity of Eucommia male flower demonstrated that it couldbe developed as a health care beverage. 2. The results showed that Eucommia male flower show strong antibacterial activitiesand antifungal activities. Further more study revealed that the Eucommia male flower extractsplays a stronger antimicrobial activity against Bacillus subtilis than ciprofloxacin. Thepetroleum ether extract and ethyl acetate extract has good antimicrobial activity, the restfraction show no inhibitory effect against fungi. The minimum inhibitory concentrations（MICs） and the minimum bactericidal concentrations （MBCs） of the petroleum ether extractand ethyl acetate extract is0.15¹2.5mg/mL,0.15²5mg/mL,0.37³.25mg/mL,0.37¹2.50mg/mL, respectively. Using Escherichia coli, Staphyloccocus aureus and Bacillussubtilis as the tested bacterial, Extracts of Eucommia male flower was also studied for itsstability to temperature, ultraviolet and pH （5⁷）. The results showed that the extracts arestable to temperature and ultraviolet and pH （5⁷）. But the rest fraction is bad stable to pH（5⁷）.3. Based on the single-factor tests, By a three-level, three-variable response surfacemethodology, the experimental data were analysised and investigated. The results showed thatthe optimum conditions of Polysaccharides from Eucommia male flowers were extractiontime of4.5h, extraction temperature of81℃and liquid-to-solid ratio of15:1（mL/g）. undersuch conditions, the yield of polysaccharides from Eucommia male flowers was up to3.47%.the relative error between the experimental and theoretical extraction rates of polysaccharideswas3.2%. The in vitro antioxidant results showed that polysaccharides from Eucommia maleflowers show scavenging ability towards DPPH free radicals and OH free radicals. and have anice reducing power.