白及多糖提取工艺及抑菌活性检测

以水提醇沉法提取白及多糖，以不同料液比、提取温度和提取时间作为实验条件，以白及多糖提取率为指标进行正交实验，从而确定最佳的提取工艺.在最佳条件下将提取得到的白及多糖以合适的用量和添加方式加入到膏剂中制成白及膏.采用滤纸片扩散法测定白及多糖提取液和白及膏对大肠杆菌和金黄色葡萄球菌的生长抑制作用.结果表明，白及多糖最佳提取工艺为料液比1∶35（g∶mL），提取温度80 ℃，提取时间4.0 h，在此提取条件下，白及多糖得率为25.97%.当质量浓度达到0.33 g/mL时，白及多糖对大肠杆菌和金黄色葡萄球菌均有抑制作用；当质量浓度提高至0.66 g/mL时，白及多糖提取液抑菌效果较强，对大肠杆菌的抑菌效果优于市售的一夫百应抑菌膏.白及膏性能稳定，对大肠杆菌抑菌效果强于金黄色葡萄球菌.

Extraction of Bletilla striata Polysaccharides and Detection of its Antibacterial Activity

Bletilla striata polysaccharides were extracted by water extraction and alcohol precipitation,with different ratio of material to liquid,extraction temperature and extraction time as the research conditions and the extraction content as the index of orthogonal experiment,so as to determine the best extraction technology.Under the optimum conditions,the extracted polysaccharides were added to the ointment to make Bletilla striata ointment.The inhibitory effects of Bletilla striata polysaccharide and Bletilla striata ointment on the growth of Escherichia coli and Staphylococcus aureus were determined by filter paper diffusion method.The results showed that the optimum extraction conditions were as follows:the ratio of material to liquid was 1:35 (g:mL),the extraction temperature was 80 ℃ and the extraction time was 4.0 h.Under these extraction conditions,the yield of polysaccharide was 25.97%.When the mass concentration of Bletilla striata polysaccharide reached 0.33 g/mL,it had inhibitory effect on Escherichia coli and Staphylococcus aureus.When the mass concentration was increased to 0.66 g/mL,the bacteriostatic effect of polysaccharide extract was stronger,and the bacteriostatic effect on Escherichia coli was better than that of commercial Yifubaiying bacteriostatic paste.The performance of Bletilla striata ointment was stable and the bacteriostatic effect against Escherichia coli was stronger than Staphylococcus aureus.