Binding Of Phenolic Compounds Research Articles

Chrysanthemum as a remarkable edible flower resource with anti‐glycation effects: Representative variety differences, phenolic compositions, and the interaction mechanism

AbstractVarious edible chrysanthemum flowers possess different anti‐glycation effects due to various compositions; however, the interaction mechanism is unclear. Our study aimed to compare the anti‐glycation effects of different edible chrysanthemum flowers and investigate the effect of phenolic compounds among them. The bovine serum albumin (BSA)‐glucose model was used for evaluating anti‐glycation effects of various chrysanthemums flowers, and C. HBJ, C. TJ, and C. JSHJ showed better anti‐glycation effects compare to aminoguanidine. Seventeen phenolic compounds were detected, and characteristic compounds were identified via omics analysis. The interactions between BSA and different phenolic acids were analyzed by molecular docking, and the anti‐glycation model was used for further verification. In this way, apigetrin, chlorogenic acid, neochlorogenic acid, quercetin‐3β‐d‐glucoside, and afzelin were identified. They were proved to affect the secondary structure of proteins due to excellent hydrophobic interactions. Our results identified the chrysanthemum species with the most promising anti‐glycation effect as well as their representative phenolic compounds. The binding of phenolic compounds and BSA due to hydrophobic interactions and hydrogen bonds might contribute to their anti‐glycation activities. Overall, our research is helpful for designing edible flower products with anti‐glycation functions and providing a better understanding of the structure–function relationship.

Effects of natural compounds on conformational properties and hairpin formation of amyloid-β42 monomer: docking and molecular dynamics simulation study

The β42 amyloid peptides (Aβ) are identified as a candidate target for Alzheimer’s drugs. Phenolic compounds can bind to the Aβ and inhibit amyloid formation. However, the inhibitory mechanism of phenolic compounds remains unclear. In this study, the molecular dynamic simulation and docking program were used to characterize the molecular details of inhibitory mechanism of the phenolic compounds. Our Results show that the phenolic compounds can bind to hydrophobic region in Aβ42 monomer and alter hydrophobic interactions network at Aβ42 which play a key role in β-sheet formation. The cluster analysis and interactions network analysis were used to probe conformational changes in Aβ42. In most populated clusters of Aβ42-phenolic compounds complexes, the sheet structures were not observed or reduced. It seems that the binding of phenolic compounds can induce larger conformational diversity for amyloid peptide and changes conformational properties of amyloid peptide. The phenolic compounds can deform β-Hairpin structure of Aβ by destabilizing salt bridges E22-K28 and D23-K28 which can alter the conformation of Aβ42 in aqueous solution. These findings are in accordance with experimental results, to some extent give a molecular level interpretation for the inhibitory mechanism of phenolic compounds .In addition, this study may add important new details to the inhibitory mechanism of Alzheimer’s drug.Communicated by Ramaswamy H. Sarma

Binding of Phenolic Compounds and Their Derivatives to Bovine and Reindeer β-Lactoglobulin

In plant-based food, phenolic compounds usually do not exist in their native form, but as esters, glycosides, or polymers. The native forms, however, require deglycosylation for their intestinal absorption, and aglycone has been considered to be the potential health-protecting/promoting form. The binding of the aglycones of phenolic compounds to bovine and reindeer beta-lactoglobulins (betaLG) using fluorescence quenching was studied. The effects of pH and storage were also studied. Of the compounds investigated, the majority of flavones, flavonols, flavanones, and isoflavones were bound to betaLG. In the pH studies, no significant effects were found. The fact that the phenolic compounds were not released at pH 2 might indicate that they bind to an external part rather than to the central cavity. Studies implicated that betaLG could act as a binder or carrier for phenolic compounds in acidic, basic, or neutral conditions and that the ligand/betaLG complex can remain stable during storage.

Three-dimensional structure and ligand binding properties of trichosurin, a metatherian lipocalin from the milk whey of the common brushtail possum Trichosurus vulpecula

Lipocalins are extracellular proteins (17-25 kDa) that bind and transport small lipophilic molecules. The three-dimensional structure of the first lipocalin from a metatherian has been determined at different values of pH both with and without bound ligands. Trichosurin, a protein from the milk whey of the common brushtail possum, Trichosurus vulpecula, has been recombinantly expressed in Escherichia coli, refolded from inclusion bodies, purified and crystallized at two different pH values. The three-dimensional structure of trichosurin was solved by X-ray crystallography in two different crystal forms to 1.9 A (1 A=0.1 nm) and 2.6 A resolution, from crystals grown at low and high pH values respectively. Trichosurin has the typical lipocalin fold, an eight-stranded anti-parallel beta-barrel but dimerizes in an orientation that has not been seen previously. The putative binding pocket in the centre of the beta-barrel is well-defined in both high and low pH structures and is occupied by water molecules along with isopropanol molecules from the crystallization medium. Trichosurin was also co-crystallized with a number of small molecule ligands and structures were determined with 2-naphthol and 4-ethylphenol bound in the centre of the beta-barrel. The binding of phenolic compounds by trichosurin provides clues to the function of this important marsupial milk protein, which is highly conserved across metatherians.

Effects of multiple weak interactions on the binding of phenolic compounds by polymeric adsorbents

AbstractTo investigate the effects of multiple weak interactions on the binding of phenolic compounds by polymeric adsorbents, macroporous polystyrene (PS) resin and PS‐based adsorbents with different hydrogen‐bond acceptor atoms (PSCH2(OCH2CH2)nOCH3, n = 0, 1, 2, and 3, denoted as PS‐EG0, PS‐EG1, PS‐EG2, and PS‐EG3) were prepared. The phenol adsorption strength order on these adsorbents was PS/PS‐EG0 < PS‐EG1 < PS‐EG2 < PS‐EG3, indicating that the adsorption on PS and PS‐EG0 was driven by hydrophobic and π–π interactions, and the adsorption on PS‐EG1, PS‐EG2, and PS‐EG3 was driven by a hydrogen bond in addition to hydrophobic and π–π interactions. PS‐EG2 may adsorb a second phenol molecule on each binding site and PS‐EG3 may adsorb second and third ones. The adsorption strength of resorcinol increased in the order of PS, PS‐EG1, and PS‐EG2, indicating that the adsorption was driven by 0, 1, and 2 hydrogen bonds in addition to hydrophobic and π–π interactions. Similarly, the adsorption of phloroglucinol on PS, PS‐EG1, PS‐EG2, and PS‐EG3 was driven by 0, 1, 2, and 3 hydrogen bonds in addition to hydrophobic and π–π interactions because the adsorption strength increased in this order. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4652–4658, 2006