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Start Over Search Limiters Peer Reviewed Topic quercetin
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1. Quercetin/chitosan-graft-alpha lipoic acid micelles: A versatile antioxidant water dispersion with high stability.

Author

Shen F, Zhong H, Ge W, Ren J, and Wang X

Subjects
Antioxidants chemical synthesis, Antioxidants chemistry, Biphenyl Compounds antagonists & inhibitors, Chitosan chemistry, Micelles, Molecular Structure, Particle Size, Picrates antagonists & inhibitors, Polymers chemical synthesis, Polymers chemistry, Quercetin chemistry, Solubility, Surface Properties, Thioctic Acid chemistry, Water chemistry, Antioxidants pharmacology, Chitosan pharmacology, Polymers pharmacology, Quercetin pharmacology, Thioctic Acid pharmacology
Abstract

Natural active compounds with antioxidant properties and other potential health benefits, like quercetin (Qu), have aroused wide concern for developing bio-functional products. However, their applications are hindered by their intrinsic poor water solubility and chemical instability. In this paper, a natural antioxidant alpha lipoic acid (ALA) was grafted onto chitosan (CS) to synthesize a novel graft polymer (CS-graft-ALA). In particular, this graft-polymer could self-assemble into spherical nanomicelles in water, with a low critical micelle concentration (CMC) of 0.0076 mg/mL. As a robust and active nanocarrier, the CS-graft-ALA micelles showed high efficiency in encapsulating Qu and dispersing Qu in water. As found, the antioxidant activity of Qu was effectively enhanced when entrapped within CS-graft-ALA micelles. Moreover, CS-graft-ALA micelles could significantly improve the photo-stability and temperature-stability of Qu. The Qu/CS-graft-ALA micelles with excellent water dispersability, stability and improved antioxidant activity hold a great potential for wide applications., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Published
2020
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2. Antioxidant potential of flavonoid glycosides from Manniophyton fulvum Müll. (Euphorbiaceae): Identification and molecular modeling

Author

Smith B. Babiaka, Rene Nia, D. H. Paper, Kennedy O. Abuga, James A. Mbah, Fidele Ntie-Kang, and Vincent de Paul N. Nziko

Subjects
Manniophyton fulvum, Multidisciplinary, Antioxidant, biology, Molecular model, Stereochemistry, medicine.medical_treatment, Euphorbiaceae, HERG, Molecular modeling, biology.organism_classification, Galactoside, Manniophyton, chemistry.chemical_compound, Rutin, chemistry, Glucoside, Antioxidant and anti-inflammatory, medicine, Flavonoid glycosides, lcsh:Q, lcsh:Science, Quercetin
Abstract

Chemical investigation of the leaves of Manniophyton fulvum led to the isolation of seven flavonoid glycosides: myricetin-3-O-β- Dd -rhamnoside (1), kaempferol-3-O-β- d -rhamnoside (2), quercetin-3-O-β- d -glucoside (3), quercetin-3-O-β- d -rhamnoside (4), quercetin-3-O-β- d -galactoside (5), rutin (6) and quercetin (7). The structures of the compounds were established by spectroscopic analyses as well as by comparison with published data. Some of the compounds showed strong antioxidant activity which validates the traditional use of the plant. An attempted correlation between the computed HOMO-LUMO energies and the measured antioxidant activities was established. We have also estimated the cardiotoxicity of the compounds by calculating the predicted logarithm of the human Ether-`a-go-go Related Gene (loghERG) using the QikProp program. These purified flavonoids are new potential lead compounds for the development of antioxidant drugs.

Published
2020

3. Ilex aquifolium: Protection Against Enzymatic and Non-Enzymatic Lipid Peroxidation

Author

D. H. Paper, Klaus Müller, and Klaus Ziereis

Subjects
Antioxidant, Neutrophils, Leukotriene B4, Rutin, medicine.medical_treatment, Pharmaceutical Science, Hyperoside, Mice, Inbred Strains, Analytical Chemistry, Lipid peroxidation, Mice, chemistry.chemical_compound, Biosynthesis, Chlorogenic acid, Drug Discovery, medicine, Animals, 12-Hydroxy-5,8,10,14-eicosatetraenoic Acid, Lipoxygenase Inhibitors, Hydrogen peroxide, Skin, Brain Chemistry, Flavonoids, Pharmacology, Arachidonate 5-Lipoxygenase, Plants, Medicinal, Plant Extracts, Organic Chemistry, Complementary and alternative medicine, chemistry, Biochemistry, Deoxyribose, Liposomes, Molecular Medicine, Cattle, Female, Quercetin, Lipid Peroxidation, Medicine, Traditional, Chlorogenic Acid
Abstract

The ethanolic extract of Ilex aquifolium L. (Aquifoliaceae) concentration-dependently inhibited leukotriene B4 biosynthesis in isolated bovine PMNL with an IC50 value of about 60 micrograms/ml, whereas the effect on epidermal 12(S)-HETE biosynthesis was much less pronounced. The extract also inhibited the non-enzymatic, peroxyl radical-stimulated lipid peroxidation in model membranes and was further a scavenger of the iron-dependent generation of hydroxyl radicals from hydrogen peroxide as determined by protection against deoxyribose degradation. While inhibition of leukotriene biosynthesis was not mediated by its known phenolic constituents such as hyperoside, rutoside, and chlorogenic acid, these compounds were responsible for the inhibitory effects of I. aquifolium against non-enzymatic lipid peroxidation and deoxyribose degradation.

Published
1998