Long chain fatty acid acylated derivatives of quercetin-3-o-glucoside as antioxidants to prevent lipid oxidation.
Flavonoids have shown promise as natural plant-based antioxidants for protecting lipids from oxidation. It was hypothesized that their applications in lipophilic food systems can be further enhanced by esterification of flavonoids with fatty acids. Quercetin-3-O-glucoside (Q3G) was esterified individually with six selected long chain fatty acids: stearic acid (STA), oleic acid (OLA), linoleic acid (LNA), α-linolenic acid (ALA), eicosapentaenoic acid (EPA) and decosahexaenoic acid (DHA), using Candida antarctica B lipase as the biocatalyst. The antioxidant activity of esterified flavonoids was evaluated using lipid oxidation model systems of poly-unsaturated fatty acids-rich fish oil and human low density lipoprotein (LDL), in vitro. In the oil-in-water emulsion, Q3G esters exhibited 50% to 100% inhibition in primary oxidation and 30% to 75% inhibition in secondary oxidation. In bulk oil, Q3G esters did not provide considerable protection from lipid oxidation; however, Q3G demonstrated more than 50% inhibition in primary oxidation. EPA, DHA and ALA esters of Q3G showed significantly higher inhibition in Cu2+- and peroxyl radical-induced LDL oxidation in comparison to Q3G.
Department of Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, NS B2N 5E3, Canada. sumudunw@dal.ca.
Sumudu N
SN
Warnakulasuriya
Department of Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, NS B2N 5E3, Canada. Ziaullah.ziaullah@dal.ca.
Ziaullah
Department of Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, NS B2N 5E3, Canada. vrupasinghe@dal.ca.
H P Vasantha
HP
Rupasinghe
D000215:Acylation; D000975:Antioxidants / Q000737:chemistry* / Q000494:pharmacology*; D003300:Copper / Q000494:pharmacology; D005227:Fatty Acids / Q000737:chemistry*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D005395:Fish Oils / Q000737:chemistry / Q000378:metabolism; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology*; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D008049:Lipase / Q000737:chemistry / Q000378:metabolism; D050356:Lipid Metabolism / Q000187:drug effects*; D008077:Lipoproteins, LDL / Q000378:metabolism*; D011794:Quercetin / Q000031:analogs & derivatives* / Q000737:chemistry
D000975:Antioxidants; D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D005395:Fish Oils; D005419:Flavonoids; D005656:Fungal Proteins; D008077:Lipoproteins, LDL; C016527:isoquercitrin; D003300:Copper; D011794:Quercetin; D008049:Lipase; C431349:lipase B, Candida antarctica