芳香酸酰化甜菜苷衍生物结合机制及其对晚期糖基化末端产物的调控作用

甜菜苷类色素是石竹木植物中广泛存在的一类水溶性天然色素，具有生物活性功能，是一种潜在的AGEs抑制剂。但由于甜菜苷稳定性差、脂溶性低，使其不易透过生物膜，生物利用度低，限制了其在医药食品中的应用。因此，项目拟以甜菜中甜菜苷为研究对象，以较强活性的甜菜苷为模式化合物，利用芳香酸作为酰基供体，酶催化酰化对其进行定向修饰。通过酶筛选、反应体系的选择及反应条件的优化，建立高效、高区域选择性的甜菜苷生物催化反应体系；对比研究甜菜苷及其酰化产物的稳定性和抗氧化活性，阐明修饰基团、取代位置及取代度对甜菜苷活性的影响规律；探讨获得的显效活性酰化衍生物对羧甲基赖氨酸的作用机制及其在“氧化应激-AGEs”的调控作用，为天然甜菜苷的结构衍生化开辟新的研究思路和方法。

Betanins in plants are water-soluble pigments exhibiting bioactive, which are a potent inhibitors of AGEs. However, the application of betanin to functional foods and its pharmaceutical formula is usually hindered because of its poor stability and low bioavailability. The main research objects of this subject are betanins and their derivatives from sugar beet. Betanins, which have high antioxidant will be synthesized through enzymatic acylation reactions in non-aqueous solvents with phenolic acids as acyl donors. A highly efficient and regioselective biocatalysis system will be established by selection of enzyme and reaction system and optimization of reaction conditions. In order to discover the effect of modified group, acylation and degree of substitution on betanins activity, Stability and antioxidant activity of betanins and their derivatives are studied. Prominent lead compounds are obtained by acylation modification, and to further explicit mechanism of inhibition of Nε-(carboxymethyl)lysine formation and its role in "oxidative stress-AGEs". This project would provide new approach for the structural modification of betanins.