Quercetin 3 glucuronide

The main kaempferol metabolite in human plasma is the 3-glucuronide. The three major metabolites of quercetin are quercetin-3-glucuronide, quercetin-3 -sulfate, and iso-rhamnetin-3-glucuronide (found at 0.1 to 1 iuM). These are accompanied by lesser amounts of the 4 -glucuronides of quercetin and isorhamnetin, and several uncharacterized metabol-... 

Table 6.6 indicates that the diet-derived PPT metabolites are able thermodynamically to scavenge some or all of the damaging radicals should they come into contact. However, these metabolites are so hydrophilic, e.g., quercetin-3-glucuronide (Ai= 0.008) " compared with quercetin and a-tocopherol (if = 550), that it is unlikely they will encounter... 

O Leary, K.A., Day, A.J., Needs, P.W., Mellon, F.A., O Brien, N.M., and Williamson, G., Metabolism of quercetin-7- and quercetin-3-glucuronides by an in vitro hepatic model the role of human (3-glucuronidase, sulfotransferase, catechol-0-methyltransferase and multi-resistant protein 2 (MRP2) in flavonoid metabolism, Biochem. Pharmacol, 65, 479, 2003. 

Kim DS, Takai H, Arai M, Araki S, Mezawa M, Kawai Y, Murota Y, Terao J, Ogata Y. 2007. Effect of quercetin and quercetin 3-glucuronide on the expression of bone sialoprotein gene. J Cell Biochem 101 790-800. 

Harborne and Saleh (1971) confirmed the presence of quercetin 3-arabinoside in the leaves of fennel and three other flavo-nol glycosides, kaempferol 3-arabinoside, kaempferol 3-glucuronide and quercetin 3-glucuronide. A chemotypic characterization of populations of fennel based on the occurrence of glycosides has been attempted. The dried distillation residue of fennel fruits contains 14-22% protein and 12-18% fat and is suitable for stock feed (Weiss, 2002). 

The flavonoids, luteolin, luteolin 7-0-/3-d-xyloside and cynaroside, were isolated by El-Moghazi et al. (1979) and orientin and vitexin by Akunzemann and Herrmann (1977). Quercetin-3-glucuronide, rutin, isoorientin, isovitexin and apigenin-7-glucoside have been reported from aniseed (Ozguven, 2000). Figure 18.2 depicts the structure of flavonoids in aniseed. 

Quercetin 3-glucuronide was the only flavonol detected in free run juices and wines (Alonso et al. 1986 Betes-Saura et al. 1996), along with trace amounts of kampferol... 

The ethanol extracts of Spica Prunellae are characterized in the upper I range by caffeic acid (Tl). In the middle and lower R/ range appear three flavono 1-glycosides [hyperoside (T2), rutin (R/ =0.26), quercetin-3-glucuronid (I =0.09)] and rosmarinic acid (T3). 

Shirai, M., Kawai, Y, Yamanishi, R., Kinoshita, T., Chiunan, H. Terao, J. (2006). Effect of conjugated quercetin metaboUtes, quercetin-3-glucuronide, on hpid hydroperoxide-dependent formation of reactive oxygen species in differentiated PC-12 cells. Free Radical Research, 40,1047-1053. 

The seeds contain glucides (coniferin, syrin-gin, benzyl-P-D-glucopyranoside and others), monoterpenoid alcohols, 2-8% (usually 3-7%) volatile oil, about 15% lipids, 20% protein, a (3(1 4) mannan, and flavonoids (quercetin-3-glucuronide, isoquercitrin, etc.), furano- and hydroxycoumarins, among others (jiANGSu marsh wichtl). "... 

Concerning other parts of grapevine, quercetin-3-glucuronide and quercetin-3-glucoside are the most important flavonols in both photosynthetic and transport... 

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