cyanidin-3-o-beta-glucopyranoside and isoquercitrin

Flavonoids are commonly abundant, plant-derived polyphenolic compounds which are responsible for color, taste, and antioxidant properties of certain plant based foods. Glucosylation by glucansucrases or other glycosyltransferases/glycoside hydrolases has been described to be a promising approach to modify stability, solubility, bioavailability, and taste profile of flavonoids and other compounds. In this study, we modified and applied a recombinant dextransucrase from Lactobacillus reuteri TMW 1.106 to glucosylate various flavonoids and flavonoid glycosides. The glucoconjugates were subsequently isolated and characterized by using two-dimensional NMR spectroscopy. Efficient glucosylation was achieved for quercetin and its glycosides quercetin-3-O-β-glucoside and rutin. Significant portions of α-glucose conjugates were also obtained for epigallocatechin gallate, dihydromyricetin, and cyanidin-3-O-β-glucoside, whereas glucosylation efficiency was low for naringin and neohesperidin dihydrochalcone. Most of the flavonoids with a catechol or pyrogallol group at the B-ring were predominantly glucosylated at position O4'. However, glycosyl substituents such as β-glucose, rutinose, or neohesperidose were glucosylated at varying positions. Therefore, mutant dextransucrase from L. reuteri TMW 1.106 can be applied for versatile structural modification of flavonoids.

Topics: Anthocyanins; Bacterial Proteins; Catechin; Flavonoids; Glucosides; Glucosyltransferases; Glycosides; Glycosylation; Limosilactobacillus reuteri; Magnetic Resonance Spectroscopy; Molecular Structure; Mutation; Quercetin; Rutin

This study was designed to evaluate the radioprotective effect of phenolics extracted from the fruits of Malus baccata (Linn.) Borkh. (MBP-3b) against damage induced by (60)Co γ-irradiation in vivo. MBP-3b could significantly improve the activity of endogenous antioxidant enzymes and the T-AOC, as well as reduce the MDA level in the liver and kidneys of irradiated mice. In addition, pretreatment with MBP-3b at a dose of 150 mg per kg bw could significantly enhance immunomodulation activity by promoting the proliferation of spenocytes and monocyte phagocytosis. The administration of MBP-3b prevented the decline induced by radiation of haematological parameters (WBC, RBC, PLT and HGB). Furthermore, MBP-3b could protect spenocytes from radiation-induced damage by inhibiting cell apoptosis. The results indicated that MBP-3b possesses strong whole body radioprotective and immunomodulatory activities. The main constituents of MBP-3b were tentatively identified as delphinidin-3,5-diglucoside, cyanidin-3-glucoside, chlorogenic acid, proanthocyanidin C1, quercetin-3-galactoside, quercetin-3-glucoside, quercetin-3-xyloside/arabinoside, phloretin-2-xyloseglucoside, quercetin-3-rhamnoside and phlorizin. MBP-3b could be used as a probable radioprotector against gamma radiation induced oxidative damage.

Topics: Animals; Anthocyanins; Antioxidants; Apoptosis; Cell Proliferation; Chlorogenic Acid; Fruit; Gamma Rays; Glucosides; Male; Malondialdehyde; Malus; Mice; Phenols; Plant Extracts; Proanthocyanidins; Quercetin; Radiation-Protective Agents; Spleen

Ozonated water dip technique was evaluated for the detoxification of six pesticides, i.e., chlorpyrifos, cypermethrin, azoxystrobin, hexaconazole, methyl parathion, and chlorothalonil from apple fruits. Results revealed that ozonation was better than washing alone. Ozonation for 15 min decreased residues of the test pesticides in the range of from 26.91 to 73.58%, while ozonation for 30 min could remove the pesticide residues by 39.39-95.14 % compared to 19.05-72.80 % by washing. Cypermethrin was the least removed pesticide by washing as well as by ozonation. Chlorothalonil, chlorpyrifos, and azoxystrobin were removed up to 71.45-95.14 % in a 30-min ozonation period. In case of methyl parathion removal, no extra advantage could be obtained by ozonation. The HPLC analysis indicated that ozonation also affected adversely the ascorbic acid and cyanidin-3-glucoside content of apples. However, 11 polyphenols studied showed a mixed trend. Gallic acid, 3,4-dihydroxybenzoic acid, catechin, epicatechin, p-coumaric acid, quercetin-3-O-glucoside, quercetin, and kaempferol were found to decrease while syringic acid, rutin, and resveratrol were found to increase in 30-min ozonation.

Topics: Anthocyanins; Ascorbic Acid; Chlorpyrifos; Chromatography, High Pressure Liquid; Coumaric Acids; Environmental Monitoring; Food Handling; Fruit; Glucosides; Malus; Ozone; Pesticide Residues; Pesticides; Polyphenols; Propionates; Pyrethrins; Quercetin

The ability of the plant flavonol quercetin and its conjugated form quercetin-3-glucoside, compared to that of the anthocyanin cyanidin-3-glucoside, to interfere with 3',5'-cyclic adenosine monophosphate (cAMP) efflux was investigated in cultured human retinal pigment epithelial (HRPE) cells.. HRPE cells were stimulated for a time course with 1 μM adrenaline, in the presence and absence of increasing concentrations of anthocyanins or flavonols, then intracellular and extracellular cAMP levels obtained from whole cells and cAMP synthetized by the activity of adenylate cyclase in cell membrane fractions were determined by radiochemical assay.. The treatment with either compound caused a significant lowering in extracellular cAMP concentrations deriving from a time course cell stimulation with 1 μM epinephrine. As to quercetin, the effect was shown to rely on the inhibition of cAMP efflux transporters. In the case of the glycoside, it was found to depend on the contrary on a reduction in the extent of epinephrine stimulation. Consistently, quercetin-3-glucoside inhibited the epinephrine-stimulated activity of adenylyl cyclase in membrane preparations, while quercetin was ineffective. The anthocyanin cyanidin-3-glucoside exerted similar effects as quercetin-3-glucoside.. Results strengthen the diverse effect of the glucosides versus the corresponding aglycones. Since differently from flavonols, anthocyanins are present in human plasma in their glycosylated form, the aglycone or glycoside forms of these plant secondary metabolites might therefore be utilized as synergistic regulators of cAMP homeostasis for therapeutical purposes.

Topics: Adrenergic beta-Agonists; Anthocyanins; Antioxidants; Cell Line; Colforsin; Cyclic AMP; Epinephrine; Glucosides; Humans; Quercetin; Retinal Pigment Epithelium; Signal Transduction

At present, little is known about the mechanisms responsible for intestinal absorption of anthocyanins (ACNs). For example, it has not yet been established if ACNs are absorbed through an active transport mechanism, such as the sodium-dependent glucose transporter (SGLT1), or by passive diffusion. Previously, we found that the absorption of ACNs differs between regions of the digestive tract and is maximal in the jejunum, suggesting that an active transport mechanism is involved. In the present study, we examined the effect of d-glucose (main substrate of SGLT1), phloridzin (inhibitor of SGLT1), and quercetin-3-glucose (Q3G, a flavonol) on the absorption of cyanidin-3-glucoside (C3G; approximately 5 micromol/L) by mouse jejunum mounted in Ussing chambers. We found that the presence of either D-glucose (10, 20, and 40 mmol/L) or phloridzin (50, 100, and 200 micromol/L) resulted in a small but insignificant inhibition of C3G disappearance from the mucosal solution (decrease of disappearance with glucose, 33%; with phloridzin, 18%; NS). However, when the flavonol Q3G (50 micromol/L) was added to the mucosal solution together with the C3G, the disappearance of C3G was significantly decreased (74%; p < 0.001), and Q3G disappeared instead. In addition, we found phloretin and quercetin, the aglycones of phloridzin and Q3G, respectively, present in the mucosal solution and tissue extracts, indicating hydrolysis of these compounds by the enterocytes of the jejunum. In contrast, the aglycone cyanidin was not detected at all. Our results show that in the mouse small intestine, ACN absorption is not solely dependent on the activity of the SGLT1 transporter, as d-glucose and phloridzin had only a slight effect on uptake. Q3G, however, clearly inhibited C3G disappearance. These results suggest that there might be a competitive inhibition between C3G and Q3G absorption. It is possible that an absorption mechanism other than the SGLT1 is involved, which has a structural preference toward flavonols.

Topics: Animals; Anthocyanins; Chromatography, High Pressure Liquid; Glucose; Glucosides; Intestinal Absorption; Intestinal Mucosa; Jejunum; Male; Mice; Phlorhizin; Quercetin; Sodium-Glucose Transporter 1