【作者】 侯建霞；

【导师】 汪云；

【作者基本信息】 江南大学 ， 分析化学， 2007， 硕士

【摘要】 苦荞麦,学名鞑靼荞麦,是一种传统的药食两用农作物,栽培历史悠久。现代临床医学观察表明,苦荞麦及其制品具有降血糖、高血脂,预防心血管疾病的能力,对糖尿病、高血压、冠心病、中风等病人都有辅助治疗作用。这些作用都与苦荞麦中含有的营养成分有关。苦荞麦中起保健作用的成分主要是荞麦中的黄酮化合物,本课题采用毛细管电泳-电化学检测(CE-ED)技术对苦荞麦籽粒中黄酮的具体成分进行了分析,研究了缓冲液的酸度、分离电压、进样时间及检测电位对三种黄酮含量测定的影响,得到了优化的测定条件。实验结果表明,苦荞中荞麦黄酮的主要成分是芦丁,其次含量较大的成分是表儿茶素、槲皮素;苦荞中黄酮的含量明显的高于甜荞。本课题对苦荞麦籽粒萌发物(荞麦芽、荞麦苗)中的黄酮化合物也进行了研究。以四川黄荞和四川黑荞两个品种为例,研究了荞麦萌发过程中荞麦黄酮的变化趋势。结果发现,萌发过程中,荞麦黄酮的含量和种类都有所变化。荞麦黄酮的含量会有很大的提高,芦丁的含量甚至会增加到原来的十几倍。荞麦芽在萌发第七天黄酮的含量达到最大,荞麦苗在萌发第十天荞麦黄酮的含量达到最大,而后开始下降。对荞麦黄酮在萌发过程中增加的生物机理进行了初步探讨。肌醇是荞麦中的又一保健因子。肌醇即环己六醇,有九个可能的立体异构体。肌-肌醇和手性肌醇是最广泛分布于植物中的两种存在形式。本课题采用毛细管电泳-电化学检测(CE-ED)技术对荞麦中这两种同分异构体的分离测定进行了研究。研究了缓冲液的种类和酸度、分离电压、进样时间及检测电位对两种物质含量测定的影响,得到了优化的测定条件。确定了以0.05mol/L硼砂缓冲液为运行液,0.1mol/L氢氧化钠为检测环境的测定体系。测定结果显示,荞麦中手性肌醇的含量远远大于肌-肌醇,其中改良的四川黑荞中,DCI的含量达到8.57mg/g,应该是长久以来起保健作用的又一支柱成分。更多还原

【Abstract】 Tartary buckwheat, or fagopyrum tataricum, has been grown for centuries. It has been used both as a food and a traditional medicine. Clinical pharmacological studies show that buckwheat and its products are effective in controlling blood sugar, reducing high blood lipid and preventing cardiovascular disease. They can help to treat patients with diabetes mellitus, hypertension, coronary heart disease and stroke. All of these functions are closely related to the active nutritional ingredients in tartary buckwheat.Flavonoid is one of the important active ingredients in tartary buckwheat, which has many physiological functions. A high-performance capillary electrophoresis (CE) method with electrochemical detection (ED) was developed for determination of flavonoids in tartary buckwheat in this work. The effects of the applied potential, the pH of running buffer, the separation voltage and the injection time on CE-ED were investigated, respectively. These experiments revealed the optimum conditions for determining three flavonoids in tartary buckwheat. Rutin was found to be the major flavonoid of tartary buckwheat, secondly were epicatechin and quercetin. The contents of flavonoids in tartary buckwheat were obvious higher than that in common buckwheat.Taking Sichuan yellow buckwheat and Sichuan black buckwheat as two examples, flavonoids in tartary buckwheat sprouts and seedings were also investigated. The experimental results show that the composition and contents of flavonoid in sprouts and seedings were different from those in seeds .As seeding days progressed, rutin, epicatechin and two unknown compounds in buckwheat sprouts and seedings were notably increased, while quercetin was moderately increased. The maximum contents of flavonoids were observed at 7th day after seeding in buckwheat sprouts and 10th day in buckwheat seedings, respectively. The biologically mechanism of this phenomenon was also tentatively explored in this work.Inositol, another important active ingredient in tartary buckwheat, is also known as hexahydroxycyclohexane that has nine different forms. The well-known and nutritionally active forms are myo-inositol (MI) and D-chiro-inositol (DCI), which are vital to many biological processes of the body, participating in a diverse range of activities. CE-ED method was applied to simultaneously determine MI and DCI in tartary buckwheat in this work. In order to obtain optimum conditions, the effects of the applied potential, the pH of running buffer, the separation voltage and the injection time on CE-ED were investigated, respectively. Finally, 0.05mol/L borate buffer was selected as the running buffer, and two analytes exhibited good response at copper-disk electrode in 0.1mol/L sodium hydroxide solution. The result showed that, in tartary buckwheat, the content of DCI was more than that of MI; in the new varieties of buckwheat of Sichuan black buckwheat, the DCI content achieves 8.57mg/g. In addition to flavonoid, DCI should be another major active ingredient in the buckwheat.更多还原