98776-99-9Relevant articles and documents
Antioxidative Properties and Chemical Changes of Quercetin in Fish Oil: Quercetin Reacts with Free Fatty Acids to Form Its Ester Derivatives
Liu, Shaojun,Zhu, Yamin,Liu, Ning,Fan, Daming,Wang, Mingfu,Zhao, Yueliang
, p. 1057 - 1067 (2021/02/01)
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-O-eicosapentaenoate and quercetin-3-O-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.
Preparation of Quercetin Esters and Their Antioxidant Activity
Oh, Won Young,Ambigaipalan, Priyatharini,Shahidi, Fereidoon
, p. 10653 - 10659 (2019/10/19)
Quercetin, a polyphenolic compound, is widely distributed in plants and has numerous health benefits. However, its hydrophilicity can compromise its use in lipophilic systems. For this reason, quercetin was esterified with 12 different fatty acids as their acyl chlorides with varying chain lengths and degrees of unsaturation. Two monoesters (Q-3′-O-monoester and Q-3-O-monoester) and four diesters (Q-7,3′-O-diester, Q-3′,4′-O-diester, Q-3,3′-O-diester, and Q-3,4′-O-diester) were the major products as was shown by HPLC-MS and 1H-NMR data. The lipophilicity of quercetin derivatives was calculated; this was found to increase with fatty acid chain length. The antioxidant potential of quercetin and its derivatives was evaluated by using DPPH radical and ABTS radical cation scavenging activity; quercetin showed the highest radical scavenging activity among all tested samples. Despite the decrease of antioxidant activity in this study, the derivatives may show better antioxidant activity in lipophilic media and display improved absorption and bioavailability in the body once consumed.
A study of synthetic approaches to 2-acyl DHA lysophosphatidic acid
Yamamoto, Yoshinori,Itoh, Toshimasa,Yamamoto, Keiko
, p. 8186 - 8192 (2017/10/13)
Lysophosphatidic acid (LPA) is a chemical mediator with a very simple glycerophospholipid structure. 1-Acyl LPA and 2-acyl LPA are biosynthesized in vivo. Unlike 1-acyl LPA, the biological function of 2-acyl LPA has been hardly elucidated and even organic synthesis of 2-acyl LPA had not been established. We suppressed acyl migration by formation of a salt with a phosphate group in order to synthesize 2-acyl LPA condensed with docosahexaenoic acid.