Interaction of flavanols with amino acids: postoxidative reactivity of the B-ring of catechin with glycine.
Interaction of flavanols with amino acids: postoxidative reactivity of the B-ring of catechin with glycine.
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DOI：
10.1021/jf5005989
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发表时间：
2014-04
影响因子：
6.1
通讯作者：
P. Guerra;V. Yaylayan
中科院分区：
文献类型：
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作者：
P. Guerra;V. Yaylayan
黄烷醇相关结构，如表儿茶素和儿茶素，与食品中潜在的抗氧化活性有关，并且已知可通过清除活性二羰基化合物来干扰美拉德反应。使用高分辨率 ESI-TOF 质谱和同位素标记技术评估甘氨酸与 (+)-儿茶素在氧化条件下于 120 °C 加热 70 分钟的反应性。基于对所得产物的精确质量分析以及[(13)C-1]甘氨酸、[(13)C-2]甘氨酸和[(15)N]甘氨酸同位素掺入模式的证据表明，(+)-儿茶素与甘氨酸形成各种加合物；其中两个包含单个氨基酸，三个加合物包含两个氨基酸部分。这些加合物中的一些在C环处发生脱水反应，并且在一些中C环保持完整。对这些加合物断裂模式的详细 MS/MS 分析证实，氨基酸部分通过席夫碱的形成添加到 (+)-儿茶素的氧化 B 环上。这种非挥发性 (+)-儿茶素/氨基酸加合物的形成使我们深入了解氨基酸如何具有改变 (+)-儿茶素的抗氧化特性的潜力，以及儿茶素如何具有改变美拉德反应概况的潜力。
Flavanol-related structures such as epicatechin and catechins have been associated with potential antioxidant activity in food and are known to interfere with the Maillard reaction through scavenging of reactive dicarbonyl compounds. High-resolution ESI-TOF mass spectrometry and an isotope labeling technique were used to assess the reactivity of glycine with (+)-catechin heated under oxidative conditions at 120 °C for 70 min. Evidence based on accurate mass analysis of the products obtained and the isotope incorporation pattern of [(13)C-1]glycine, [(13)C-2]glycine, and [(15)N]glycine experiments indicated that (+)-catechin formed various adducts with glycine; two of them incorporated a single amino acid, and three adducts incorporated two amino acid moieties. Some of these adducts underwent dehydration reaction at ring C, and in some the C-ring remained intact. Detailed MS/MS analyses of the fragmentation patterns of these adducts have confirmed the addition of amino acid moieties to the oxidized B-ring of (+)-catechin through the formation of Schiff bases. Formation of such nonvolatile (+)-catechin/amino acid adducts provides insight into how amino acid can have the potential of modifying the antioxidant properties of (+)-catechin and how catechin in turn has the potential of modifying the profile of the Maillard reaction.