Discriminative Analysis of Free and Esterified Gallic Acids in Acorn Shells
Discriminative Analysis of Free and Esterified Gallic Acids in Acorn Shells
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橡子壳中游离没食子酸和酯化没食子酸的判别分析
DOI：
10.1016/j.jaap.2015.09.019
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Seung-Cheol Lee et al.
中科院分区：
文献类型：
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作者：
Yasuyuki Ishida;Seung-Cheol Lee et al.
在有机碱存在下，通过热化学-气相色谱/质谱（Thermochemolysis-GC/MS）分析，发现废弃橡子壳中含有抗坏血酸类抗氧化活性突出的酚类化合物。使用四甲基氢氧化铵（TMAH）通过热化学裂解-GC/MS获得的完整橡子壳样品的色谱图显示出3，4，5-三甲氧基苯甲酸甲酯的强峰。在橡子壳的甲醇和水提取物的色谱图上也清楚地观察到该产物，表明3，4，5-三甲氧基苯甲酸甲酯是通过热化学分解反应由游离和/或酯化的没食子酸衍生的。基于峰强度，没食子酸成分的含量测定asca。27重量%的两种提取物。此外，游离没食子酸的含量进行了选择性的估计与区分其酯化对应物，通过使用四甲基乙酸铵（TMAAc）作为甲基化试剂。这些结果也与高抗氧化活性的橡子壳提取物DPPH自由基清除方法进行了评估。
The presence of phenolic compounds, possessing outstanding antioxidant activity corresponding to ascorbic acid, in wasted acorn shells was revealed by means of thermochemolysis-gas chromatography/mass spectrometry (thermochemolysis-GC/MS) in the presence of organic alkalis. The chromatogram of intact acorn shell samples obtained by thermochemolysis-GC/MS using tetramethylammonium hydroxide (TMAH) showed a strong peak of 3,4,5-trimethoxybenzoic acid methyl ester. This product was also clearly observed on the chromatograms of the methanol and water extracts from the acorn shells, indicating that 3,4,5-trimethoxybenzoic acid methyl ester was derived from free and/or esterified gallic acids through the thermochemolysis reaction. Based on the peak intensities, the contents of gallic acid components were determined asca.27 wt% for the both extracts. Furthermore, the content of free gallic acid was selectively estimated with discriminating from its esterified counterpart by using tetramethylammonium acetate (TMAAc) as a methylating reagent. These results were also correlated with high antioxidant activity of the acorn shell extracts evaluated by a DPPH radical scavenging method.