College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China.
Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture, Shanghai 201306, China.
J Agric Food Chem. 2021 Jan 27;69(3):1057-1067. doi: 10.1021/acs.jafc.0c07273. Epub 2021 Jan 13.
In this research, we studied the antioxidative properties and chemical changes of quercetin in fish oil during accelerated storage at 60 °C for 5 days. Gas chromatography (GC) analysis showed that quercetin inhibited aldehyde formation and unsaturated fatty acid oxidation in fish oil significantly; however, the inhibitory effects decreased gradually with prolonged heating time. Moreover, quercetin was consumed with increasing heating time. Some new phenolic derivatives were discovered in the fish oil with quercetin, with their structures fully elucidated by LC-MS/MS and comparison with newly synthesized ones (characterized by MS and NMR spectroscopy). Based on their chemical structures, we proposed that quercetin reacted with EPA and DHA to form the corresponding quercetin fatty acid esters in fish oil. In addition, the newly formed quercetin-3--eicosapentaenoate and quercetin-3--docosahexaenoate showed weaker DPPH and ABTS radical cation scavenging activity but much improved lipophilicity, higher cell membrane affinity, and hence enhanced cellular antioxidant activity compared with the parent quercetin. Overall, quercetin could be used as a safe dietary polyphenol to inhibit lipid oxidation. The newly formed quercetin-polyunsaturated fatty acid esters may render improved bioactivity to humans, which needs further investigation.
在这项研究中，我们研究了在 60°C 下加速储存 5 天期间，鱼油中槲皮素的抗氧化性能和化学变化。气相色谱 (GC) 分析表明，槲皮素可显著抑制鱼油中醛的形成和不饱和脂肪酸的氧化；然而，随着加热时间的延长，抑制作用逐渐减弱。此外，随着加热时间的增加，槲皮素被消耗。在含有槲皮素的鱼油中发现了一些新的酚类衍生物，其结构通过 LC-MS/MS 与新合成的衍生物（通过 MS 和 NMR 光谱表征）进行了充分阐明。基于它们的化学结构，我们提出槲皮素与 EPA 和 DHA 反应，在鱼油中形成相应的槲皮素脂肪酸酯。此外，新形成的槲皮素-3--二十碳五烯酸酯和槲皮素-3--二十二碳六烯酸酯表现出较弱的 DPPH 和 ABTS 自由基阳离子清除活性，但脂溶性、细胞膜亲和力显著提高，从而增强了细胞抗氧化活性，与母体槲皮素相比。总的来说，槲皮素可用作一种安全的饮食多酚来抑制脂质氧化。新形成的槲皮素-多不饱和脂肪酸酯可能会赋予人体更好的生物活性，这需要进一步研究。
