巨尾桉单宁的提取分离及其抗菌抗氧化性能

采用超声波辅助法提取了巨尾桉叶中的单宁,大孔树脂吸附法纯化了粗提物,考察了提取物对8种常见菌种的抑制作用和对H2O2、DPPH.和.OH的清除作用。结果表明,巨尾桉单宁的提取得率为4.01%;经树脂分离纯化后单宁质量分数达到53.12%;巨尾桉单宁对除大肠杆菌外的供试菌种均有较强的抑制作用,纯化后的单宁对金黄色葡萄球菌、酵母菌和痢疾杆菌的最低抑菌质量浓度(MIC)均为1.0 g/L,对蜡状芽孢杆菌和沙门氏菌的抑制作用优于阳性对照物;粗提物、纯化物在质量浓度为0.50 g/L时对H2O2有最大清除率,分别为80.00%、89.12%,其IC50分别为0.11、0.12 g/L;抗坏血酸、粗提物和纯化物均在质量浓度为1.50 g/L时对DPPH.有最大清除率,分别为98.43%、88.97%和92.21%。在清除.OH体系中,粗提物、纯化物均在质量浓度为4.00 g/L时有最大清除率,分别为87.52%和94.32%,各试样对.OH的清除能力依次为抗坏血酸>纯化物>粗提物。

Extraction, Separation of Tannins from Eucalyptus Grandis

Ultrasound assisted extraction was adopted to extract tannins from Eucalyptus grandis x E.urophylla.The crude extract tannins was purified by the macroporous resin adsorption.The antimicrobial activity of tannins on multiple common bacteria was studied by way of filter paper method,and the oxidation resistance of the samples was studied by way of three different systems.Tannin in crude extract was 4.01% and increased to 53.12% when it was chromatographied by macroporous resin.Tannins had strong inhibition on the 7 kinds of bacteria activity but exhibited no distinct inhibition on Excherichia coli.Minimum antimicrobial mass concentration of the purified tannins on Staphyloccocus aureus,Yeast and Shigella was 1.0 g/L,and the antimicrobial activity against Live Bacillus Cereus Preparation and Salmonella was stronger than that against positive control.The maximum scavenging rates of crude tannins and purified tannins for H2O2 were 80.00% and 89.12% respectively when the mass concentration was 0.50 g/L,and their IC50 were 0.11 g/L and 0.12 g/L,respectively.The maximum scavenging rates of Vc,crude tannins and purified tannins for DPPH· were 98.43%,88.97% and 92.21% respectively.When the mass concentration was 4.00 g/L,the highest scavenging rate of crude tannins and purified tannins for ·OH were 87.52% and 94.32% respectively.