The non-oxidative degradation of ascorbic acid at physiological conditions
The non-oxidative degradation of ascorbic acid at physiological conditions
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DOI：
10.1016/s0925-4439(00)00009-0
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发表时间：
2000-04-15
影响因子：
6.2
通讯作者：
Ortwerth, BJ
中科院分区：
文献类型：
--
作者：
Simpson, GLW;Ortwerth, BJ
研究了L-抗坏血酸（阿萨）及其主要氧化产物L-脱氢抗坏血酸（DHA）和3，3-L-二酮古洛酸（3，3-DKG）在生理条件下的降解。分析确定，无论使用哪种化合物作为起始物料，L-藜芦酮糖（ERU）和草酸盐均为阿萨的主要降解产物。ERU的鉴定通过质子去耦C-13-核磁共振光谱法确定，并通过高效液相色谱法和酶分析进行定量。ERU的摩尔产率从？，3-DKG在pH 7.0、37 ℃和限制O-2时> 97%。这种新的阿萨降解的酮糖产物还通过气液色谱法和薄层色谱法进行了定性鉴定。ERU是一种反应性极强的酮糖，可迅速使蛋白质发生变性和交联，因此可介导体外观察到的蛋白质的AsA依赖性修饰（抗坏血酸化），也被认为在糖尿病和老年性白内障形成期间在体内发生在人透镜中。(C)2000由Elsevier Science B. V.出版，保留所有权利。
The degradation of L-ascorbate (AsA) and its primary oxidation products, L-dehydroascorbate (DHA) and 3,3-L-diketogulonate (3,3-DKG) were studied under physiological conditions. Analysis determined that L-erythrulose (ERU) and oxalate were the primary degradation products of ASA regardless of which compound was used as the starting material. The identification of ERU was determined by proton decoupled C-13-nuclear magnetic resonance spectroscopy, and was quantified by high performance liquid chromatography, and enzymatic analysis. The molar yield of ERU from ?,3-DKG at pH 7.0 37 degrees C and limiting O-2, was > 97%. This novel ketose product of AsA degradation, was additionally qualitatively identified by gas-liquid chromatography, and by thin layer chromatography. ERU is an extremely reactive ketose, which rapidly glycates and crosslinks proteins, and therefore may mediate the AsA-dependent modification of protein (ascorbylation) seen in vitro, and also proposed to occur in vivo in human lens during diabetic and age-onset cataract formation. (C) 2000 Published by Elsevier Science B.V. All rights reserved.