linoleic-acid and 3-methylquercetin

The peroxidation of linoleic acid (LA) in the presence of copper(II) (Cu(II)) ions alone and with α-tocopherol (α-TocH) was investigated in aerated and incubated emulsions at 37 °C and pH 7. Additionally, the effects of quercetin (QR) and its O-methylated derivative, isorhamnetin (IR), as potential antioxidant protectors were studied in the (Cu(II) + TocH)-induced LA peroxidation system. Cu(II)-induced LA peroxidation followed pseudo-first-order kinetics with respect to primary (hydroperoxides) and secondary (aldehydes- and ketones-like) oxidation products, which were determined by ferric thiocyanate and thiobarbituric acid-reactive substances methods, respectively. As opposed to the concentration-dependent (at 0.6 and 10.0 µM) prooxidative action of α-TocH in the absence of QR and IR, the latter two compounds showed antioxidant effect over TocH. The peroxidation of LA in the presence of Cu(II)-H(2)O(2) combination alone and with TocH, QR and IR were also investigated in aerated and incubated emulsions, where the latter three compounds exhibited antioxidant effects.

Topics: alpha-Tocopherol; Antioxidants; Copper; Hydrogen Peroxide; Linoleic Acid; Lipid Peroxidation; Oxidants; Quercetin

Teramnus labialis and T. uncinatus are both underutilized legume species. Teramnus labialis is used as food in India while T. uncinatus has potential use in pasture mixes. Photoperiod-sensitive Teramnus accessions were grown in the greenhouse from 2010 to 2011 and evaluated for flavonol content, oil%, and fatty acid compositions. Significant variations for seed numbers produced, flavonol content, oil%, and fatty acid compositions were detected. Seed numbers ranged from 16 to 3,792 in both species. Teramnus accessions produced more quercetin (ranging from 0.615 to 2.228 mg/g) in their seeds than the other flavonols. However kaempferol and isorhamnetin content ranged from 0 to 0.066 and 0 to 0.086 mg/g (dry seed weight basis), respectively among all accessions. Oil% ranged from 2.65 to 5.64% and more oleic, linoleic, and linolenic acids ranging from 6.69 to 25.97, 31.82 to 41.44, and 17.7 to 32.66%, respectively, were produced among all Teramnus accessions. The seeds from all Teramnus accessions also produced the least saturated fatty acid compositions (ranging from 0.08 to 15.36%). Several significant correlations were also detected for these traits among the accessions. Quercetin showed highly significant positive correlations with kaempferol (r = 0.59, p < .0001), oil% (r = 0.58, p < .0001), and oleic acid (r = 0.31, p < .001). Quercetin also showed a significant negative correlation with linoleic acid (r = -0.49, p < .0001). These correlations are important because useful breeding procedures could be conducted on improving flavonol, oil%, and fatty acid compositions in Teramnus labialis and T. uncinatus accessions.

Topics: alpha-Linolenic Acid; Dietary Supplements; Fabaceae; Fatty Acids; Flavonols; Humans; India; Kaempferols; Linoleic Acid; Oleic Acid; Plant Oils; Quercetin; Seeds; Species Specificity