Abstract: In this study,polysaccharide (OLP) was purified from the Olea europaea L.leaf,the monosaccharide components of OLP was determined using 1-phenyl-3-methyl-5-pyrazolone (PMP) pre-column derivatization-HPLC analysis.The in vitro antioxidant of OLP was evaluated by DPPH,hydroxyl radical,and superoxide anion radical scavenging and Fe²⁺ chelating assay.Filter paper disc method was used to determine the antibacterial activity of OLP.The results showed OLP was an acidic polysaccharide,and the monosaccharide composition was mannose,rhamnose,glucuronic acid,galacturonic acid,glucose,galactose and arabinose.The IC₅₀ of OLP scavenging DPPH,hydroxyl radical,superoxide anion radical and chelating Fe²⁺ were 0.522,2.345,1.934 and 3.420mg/mL,respectively,indicating OLP had good antioxidant activity.Meanwhile,the MIC of OLP against Escherichia coli, Staphyloccocus aureus, Bacillus subtilis and Pseudomonas aeruginosa were 1.25,2.50,2.50 and 5.00 mg/mL,respectively.The results showed that the antibacterial activity of OLP against gram negative bacteria was better than gram positive bacteria.

Key words: Olea europaea L.leaf, polysaccharide, antioxidant activity, antimicrobial activity