中文摘要：

【目的】比较铁皮石斛原球茎多糖与野生铁皮石斛多糖的抗菌及体外抗氧化活性，为铁皮石斛组织培养物的应用提供依据。【方法】以大肠杆菌（Escherichiacoli）、金黄色葡萄球菌（Staphylococcus aureus）、枯草芽孢杆菌（Bacillussubtilis）、白色念珠菌（Candidaalbicans）为供试菌，用抑菌圈法测定2种铁皮石斛多糖对目标菌的抗菌活性；分别用羟自由基（·0H）、超氧阴离子自由基（O2－）、1，1-二苯基-2-三硝基苯肼自由基（DPPH·）法和硫代巴比妥酸法（TBA法）结合分光光度法检测2种铁皮石斛多糖清除·OH、O2-和DPPH·及抗脂质过氧化的能力，比较2种铁皮石斛多糖的抗菌及体外抗氧化活性。【结果】铁皮石斛原球茎多糖与野生铁皮石斛多糖对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌、白色念珠菌均具有显著的抑制作用，且野生铁皮石斛多糖的抑菌效果比铁皮石斛原球茎多糖优；2种铁皮石斛多糖对·OH、OS和DPPH·均有极显著的清除作用，对小鼠肝组织脂质过氧化均有极显著的抑制作用，且野生铁皮石斛多糖比铁皮石斛原球茎多糖效果更好，2种铁皮石斛多糖的抗菌及抗氧化活性与多糖质量均存在剂量效应关系。【结论】与野生铁皮石斛多糖相比，铁皮石斛原球茎多糖在抗菌、抗氧化能力方面虽存在一定差距，但仍具有进一步开发的价值。

英文摘要：

[Objective] This study compared the antibacterial and antioxidant activities of polysaccha- rides of Dendrobiurn candidum protocorms and wild Dendrobium to provide basis for application of Den- drobium candidum tissue cultures. [Method] Bacteriostatic ring method with Escherichia coli, Staphylo- coccus aureus,Bacillus subtilis, and Candida albicans was used to determine the antibacterial activity of polysaccharides. Combined with spectrophotometric method,the hydroxyl radical （ OH） system,superox- ide anion free radical （Of） system, 1,1-two phenyl-2-three nitro hydrazyl free radical （DPPH ） method and thiobarbituric acid （TBA） method were used to detect and compare their capability of scavenging （ OH）, （O2＇） and （DPPH ） and anti-lipid peroxidation capability. [Result] Both polysaccharides had significant inhibitory effects against Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Candida albicans. Inhibitory effect of polysaccharide from wild Dendrobium was stronger than that of polysaccharide from Dendrobium candidum protocorms. Both polysaccharides had significant scavenging effect on OH, O2 and DPPH and significant inhibitory effect on lipid peroxidation in liver tissue of mice. Antioxidant effect of polysaccharide from wild Dendrobium was stronger than that of polysaccharide from protocorms of Dendrobium candidum. There was a dose effect relationship between antibacterial and antioxidant activi- ties and polysaccharide concentration. [Conclusion] The antibacterial and antioxidant abilities of polysac- charide from Dendrobium candidum protocorms were not as good as those of polysaccharide from wild Dendrobium. However,it is worthy to further develop polysaccharide from Dendrobium candidurn proto- corms.