Abstract:Mangosteen （Garcinia mangostana）pericarp was treated as the source material and the extracted yield of its polysaccharides was considered as the index.A series of orthogonal experiments，which were based on single-factor experimentation，were carried out to explore the effects of the ratio of material to liquid，extraction temperature，and ultrasound time on the extraction yield of polysaccharides.The antioxidant activity of the polysaccharides was investigated and their antibacterial effects were tested using the microbroth dilution method.The inhibitory effects of the polysaccharides on the proliferation of tumor cells was evaluated using a cell counting kit-8（CCK-8）assay.Based on the experimental results，the optimal conditions for polysaccharide extraction were determined to be：a solid-liquid ratio of 1 ∶40（g/mL），an extraction temperature of 55 ℃ and an ultrasonic time of 40 min.Under the above conditions，the extraction rate of the polysaccharides was（12.99 ±0.48）%.The DPPH radical，OH radical and ABTS+radical scavenging assay IC50values were 69.25，462.50，18.39 μg/mL，respectively.The polysaccharides displayed antimicrobial activity for several bacterial species，including Staphylococcus aureus，Escherichia coli，Klebsiella pneumoniae，Pseudomonas aeruginosa and Acinetobacter baumannii with MIC values of 0.391，3.125，3.125，6.25，25.00 mg/mL，respectively.The polysaccharides exhibited no cytotoxicity toward MCF-7 and B16 cells and exhibited lower cytotoxicity for DLD-1 and A375 cells with IC50values of 76.66 μg/mL and 127.70 μg/mL，respectively.