权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

BIO-ANTIOXIDATION MECHANISM AND PHSIOLOGICAL FUNCTION OF L-ASCORBIC ACID

L-抗坏血酸的生物抗氧化机制和生理功能

基本信息

批准号：
09660133
负责人：
KURATA Tadao
金额：
$ 2.11万
依托单位：
OCHANOMIZU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

项目摘要

L-Ascorbic Acid(ASA), which is also called Vitamin C, is an essential water soluble nutrient, and is widely known to be involved in the blo-synthesis of collagen, metabolism of aromatic amino acids, lipid metabolism, activation of immune system and cell multiplication. However, the detailed mechanism of the biological function of ASA is still unknown. Furthermore, ASA is widely used as antioxidant in food storage and processing making use of its very strong reducing property. Recently, there have been many reports which describe the relationship between the antioxidant function and biological function, however the details of their relationship is still unclear. In order to clarify the detailed correlation between the biological function and antioxidant function of ASA, both experimental and computational chemical methods were applied to elucidate these unresolved problems. First, the optimized structures of ASA and its related compounds were calculated, and other various physico-chemical parameters, such as electron densities, dipole moment, heat of formation etc., were obtained by semi-empirical molecular orbital calculations. The auto-oxidation reaction mechanism of ASA molecule with triplet oxygen molecule was also clarified. Identification of various auto-oxidation products including threonic acid and oxalic acid were made and confirmation of the production of super-oxide anion during the auto-oxidation of ASA was also made, Based on the results obtained in this study, a new auto-oxidation mechanism of ASA was proposed.

L-抗坏血酸（阿萨），也称为维生素C，是一种必需的水溶性营养素，并且众所周知参与胶原蛋白的生物合成、芳香族氨基酸的代谢、脂质代谢、免疫系统的激活和细胞增殖。然而，阿萨的生物学功能的详细机制仍然是未知的。此外，阿萨利用其非常强的还原性被广泛用作食品储存和加工中的抗氧化剂。近年来，有许多报道描述了抗氧化功能和生物学功能之间的关系，但它们之间的关系的细节仍然不清楚。为了阐明阿萨的生物学功能和抗氧化功能之间的详细关系，实验和计算化学方法被应用于阐明这些尚未解决的问题。首先，计算了阿萨及其相关化合物的优化结构，并计算了电子密度、偶极矩、生成热等各种物理化学参数，通过半经验分子轨道计算得到。阐明了阿萨分子与三重态氧分子的自氧化反应机理。确定了ASA的自氧化产物苏糖酸和草酸，并证实了阿萨自氧化过程中超氧阴离子的产生，据此提出了阿萨自氧化的新机理。