【摘要】 【目的】研究板栗雄花序不同萃取物的抗氧化及抑菌效果,为其进一步开发与利用提供基础。【方法】用不同极性溶剂对板栗雄花序乙醇浸膏进行萃取分离,得到石油醚萃取物、二氯甲烷萃取物、乙酸乙酯萃取物、正丁醇萃取物4个部分;并采用1,1-二苯基-2-三硝基苯肼(DPPH·)自由基清除和硫代巴比妥酸法测定醇提物及不同萃取物的抗氧化能力,以滤纸片琼脂扩散法和共培养测定抗菌活性。利用高效液相色谱法(HPLC)和核磁共振波谱法(NMR)鉴定出板栗雄花序中的鞣花酸(EA),并对其进行初步定量与结构分析。【结果】1)通过系统提取法得到板栗雄花序醇提物提取率为16.6%,其他4种萃取物提取率在2.6%~26.2%,其中乙酸乙酯萃取物提取率最高。2)板栗雄花序醇提物及不同萃取物对DPPH·自由基、卵黄脂质过氧化物都有一定的清除能力,其中乙酸乙酯萃取浓度为0.01 mg·m L-1时,对DPPH·清除率达到94.4%,对卵黄脂质过氧化物的清除率为95.69%,与同浓度的抗坏血酸(Vc)和2,6-二叔丁基-4-甲基苯酚(BHT)清除率相当。3)板栗雄花序醇提物对12种细菌都有一定程度的抑制效果,在不同萃取物中乙酸乙酯萃取物抑菌效果最好,对大肠杆菌的最低抑菌浓度为0.98 mg·m L-1,最低杀菌浓度为1.96 mg·m L-1。板栗雄花序样品中有游离鞣花酸,含量为2.267 mg·g-1。【结论】板栗雄花序中含有较多抗氧化和抑菌的活性物质,其醇提物及不同极性萃取物的抗氧化能力存在较大差异,乙酸乙酯萃取物抗氧化活性较高,对清除DPPH·自由基和脂质过氧化物都有较好的效果。各个萃取物对G+菌和G-菌都有一定作用,其中乙酸乙酯萃取相的抑菌活性最好。更多还原

【Abstract】 【Objective 】In this study, effects of the different extracts of chestnut catkins on antioxidation and antibacterial were investigated to provide a basis for the further development and utilization of the catkins. 【Method 】Methanol extract of chestnut catkins was further partitioned with petroleum ether,dichloromethane,ethyl acetate and nbutyl alcohol and four crude extractives were successively obtained. The antioxidant activities of the different extractives were evaluated by two methods: 2,2-diphenyl-1-picrylhydrazyl( DPPH) radical scavenging ability and resistance to the peroxidation of unsaturated fatty acids in egg yolk. The antimicrobial activity was analyzed by agar diffusion and co-culture method. The structural formula and content of ellagic acid( EA) in the extractives were determined by HPLC and NMR.【Result】1) Extraction rate of chestnut catkins through methanol extractives was 16. 6%,and the rates of other four extractives were between 2. 6 % to 26. 2 % with ethyl acetate extract the highest. 2) All of extractives were able to some degrees to scavenge DPPH radical and yolk lipid peroxide. Among them, ethyl acetate extract possessed similar antioxidation level compared with vitamin C( Vc) and 2,6- tert butyl-4- methyl phenol( BHT). The rates of scavenging DPPH radical and yolk lipid peroxide were 94. 4 % and 95. 69 % under a concentration of 0. 01 mg m L- 1,respectively.3) Antimicrobial activity of the methanol extract of chestnut catkins was effective to 12 kinds of bacteria. The ethyl acetateextract had the most inhibitory effect to bacteria in different extractives and the minimum inhibitory concentration and the minimum bactericidal concentration against Escherichia coli were 0. 98 mg·m L- 1and 1. 96 mg·m L- 1,respectively. The content of free ellagic acid was 2. 267 mg · g- 1. 【Conclusion 】Chestnut catkins contain abundant antioxidant and antibacterial substances. The antioxidant capacity was different among alcohol extracts of chestnut catkins and polar extracts. The ethyl acetate extract has higher antioxidant activity and higher scavenging rate to DPPH radical and lipid peroxides. Various extractives have to different degrees effects on the G+and G-bacteria,and antibacterial activity of ethyl acetate extract has the highest effect among the several extractives.更多还原