orientin has been researched along with hyperoside* in 2 studies
2 other study(ies) available for orientin and hyperoside
| Article | Year |
|---|---|
Inhibition of the MurA enzyme in Fusobacterium nucleatum by potential inhibitors identified through computational and in vitro approaches.
Fusobacterium nucleatum plays a key role in several diseases such as periodontitis, gingivitis, appendicitis, and inflammatory bowel disease (IBD). The development of antibiotic resistance by this bacterium demands novel therapeutic intervention. Our recent study has reported UDP-N-acetylglucosamine 1-carboxyvinyltransferase (MurA) as one of the potential target proteins in F. nucleatum. In this study, we proposed two novel MurA inhibitors through in silico screening and evaluated their mode of inhibition by in vitro experiments. It was found that MurA structural arrangement (inside-out α/β barrel) was stabilized by L/FXXXG(A) motif-based interactions. The protein was maintained in an open or substrate-free conformation due to repulsive forces between two parallelly arranged positively charged residues of domain I and II. In this conformation, we identified six best compounds that held key interactions with the substrate-binding pocket via a structure-based virtual screening of natural and chemical compound libraries. However, among these, only orientin and quercetin-3-O-d-glucuronide (Q3G) showed better interaction capability through consistent H-bond occupancy and lowest binding free energy during molecular dynamic simulations. In vitro inhibition studies evidenced the mixed and uncompetitive mode of inhibition by orientin and Q3G, respectively, with purified MurA protein. This explains the binding of orientin in both open and closed (substrate-bound) conformations of MurA, and Q3G binding in only closed conformation. Therefore, the Q3G binding mode was predicted on a MurA-substrate complex, which highlighted its constant H-bond with Cys118, a phosphoenolpyruvate (PEP) interacting residue. This suggests that Q3G may interrupt the PEP binding, thereby inhibiting the MurA activity. Thus, the current study discusses the structure of MurA and demonstrates the inhibitory action of two novel compounds. Topics: Alkyl and Aryl Transferases; Bacterial Proteins; Computational Biology; Computer Simulation; Drug Evaluation, Preclinical; Enzyme Inhibitors; Flavonoids; Fusobacterium nucleatum; Glucosides; Hydrogen Bonding; Models, Molecular; Molecular Dynamics Simulation; Protein Conformation; Quercetin; Structure-Activity Relationship | 2017 |
Anti-peroxyl radical quality and antibacterial properties of rooibos infusions and their pure glycosylated polyphenolic constituents.
The anti-peroxyl radical quality of two aqueous rooibos infusions and solutions of their most abundant glycosylated polyphenols was evaluated using pyrogallol red and fluorescein-based oxygen radical absorbance ratios. It was observed that the artificial infusions, prepared using only the most abundant polyphenols present in rooibos and at concentrations similar to those found in the natural infusions, showed greater antioxidant quality than the latter infusions, reaching values close to those reported for tea infusions. Additionally, the antimicrobial activity of the natural and artificial infusions was assessed against three species of bacteria: Gram (+) Staphylococus epidermidis and Staphylococcus aureus and Gram (-) Escherichia coli. When compared to the natural infusions the artificial beverages did not demonstrate any bacterostatic/cidal activity, suggesting that the antibacterial activity of rooibos is related to compounds other than the glycosylated polyphenols employed in our study. Topics: Anti-Bacterial Agents; Apigenin; Aspalathus; Beverages; Chalcones; Escherichia coli; Flavonoids; Free Radical Scavengers; Glucosides; Microbial Sensitivity Tests; Peroxides; Plant Extracts; Polyphenols; Quercetin; Rutin; Staphylococcus aureus; Staphylococcus epidermidis | 2013 |