枣叶枣芽中黄酮含量测定及其清除DPPH自由基的作用

Determination of flavonoid in jujube leaves and buds and its effects on removal of DPPH free radicals

为进一步提高枣产品的附加值,实现枣树的综合开发利用,试验采用紫外分光光度法和高效液相色谱法分别对4种不同采摘时期(盛花后第0天和第7天)的枣叶和枣芽样品进行黄酮含量的测定,并分析了各样品醇提物对DPPH自由基的清除效果.结果表明:两种方法均可用于黄酮类化合物的分析检测.不同采摘时间、部位及品种的样品中黄酮含量各不相同,除骏枣叶的黄酮含量略低于骏枣芽外,‘七月’枣、‘大王’枣及‘灰枣’的枣叶黄酮含量均比枣芽中的高.其中6月12日采摘的七月枣叶中黄酮含量最高为18.84mg/g,其醇提物对DPPH自由基的清除率达到43.18%,显著高于对照.说明各样品对DPPH自由基均有一定的清除作用,且与其中的黄酮含量高度相关,可做为有效的天然自由基清除剂.

Four kinds of jujube leave and bud which picked in different period were quantified for fla- vones by ultraviolet spectrophotometry （UV） and High Performance Liquid Chromatography （HPLC）, their alcohol extracts to scavenge activity of DPPH were also analyzed. The results showed that both meth- Ods （UV and HPLC） could be used for the analysis and detection of flavonoids, HPLC showed higher sen- sitivity and accuracy. Picking periods, parts and varieties made different flavone contents,leaves tended to be higher than buds in cultivars ＇ Qiyue ~＇ Dawang ~ and ＇ Hui ~ jujube： ＇Jun ~ jujube showed opposite tend- ency,leaves were a little lower than buds. ＇Qiyue＇ leaves picked in July 12 th had the highest amount of flavone components, and its alcohol extracts could scavenge DPPH free radicals for 43. 18%, much higher than the control groups, meanwhile the effects of eliminating free radicals submitted positive pertinence with flavone concentration.