Department of Food Science and Nutrition, Fuli Institute of Food Science, Zhejiang University, Hangzhou 310058, China.
Ningbo Research Institute, Zhejiang University, Ningbo 315100, China.
Molecules. 2022 Oct 27;27(21):7301. doi: 10.3390/molecules27217301.
In this study, a novel galloyl phytol antioxidant was developed by incorporating the branched phytol chain with gallic acid through mild Steglich esterification. The evaluation of the radical scavenging activity, lipid oxidation in a liposomal model, and glycerol trioleate revealed its superior antioxidant activities in both dispersed and bulk oils. Then, the antioxidant capacity enhancement of galloyl phytol was further explored using thermal gravimetry/differential thermal analysis (TG/DTA), transmission electron microscopy (TEM), and molecular modeling. The EC50 values of GP, GPa, and GE were 0.256, 0.262, and 0.263 mM, respectively, which exhibited comparable DPPH scavenging activities. These investigations unveiled that the branched aliphatic chain enforced the coiled molecular conformation and the unsaturated double bond in the phytol portion further fixed the coiled conformation, which contributed to a diminished aggregation tendency and enhanced antioxidant activities in dispersed and bulk oils. The remarkable antioxidant performance of galloyl phytol suggested intriguing and non-toxic natural antioxidant applications in the food industry, such as effectively inhibiting the oxidation of oil and improvement of the quality and shelf life of the oil, which would contribute to the use of tea resources and extending the tea industry chain.
在这项研究中，通过温和的 Steglich 酯化反应，将支链植醇链与没食子酸结合，开发出了一种新型的没食子酰基植醇抗氧化剂。通过对自由基清除活性、脂质体模型中的脂质氧化和甘油三油酸酯的评估，发现其在分散油和块状油中均具有优越的抗氧化活性。然后，通过热重/差示热分析 (TG/DTA)、透射电子显微镜 (TEM) 和分子建模进一步探索了没食子酰基植醇的抗氧化能力增强作用。GP、GPa 和 GE 的 EC50 值分别为 0.256、0.262 和 0.263 mM，表现出相当的 DPPH 清除活性。这些研究表明，支链脂肪链强制形成卷曲分子构象，而植醇部分的不饱和双键进一步固定了卷曲构象，这导致聚集趋势减弱，在分散油和块状油中的抗氧化活性增强。没食子酰基植醇的显著抗氧化性能表明，它在食品工业中有作为一种有趣且无毒的天然抗氧化剂的应用潜力，例如有效抑制油脂氧化，提高油脂的质量和保质期，从而有助于茶叶资源的利用和茶产业的延伸。
