Study On Active Components Of Buckwheat And Theirs Changes During Seeding Progress

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.