scholarly journals Exploring Flexibility, Intermolecular Interactions and Admet Profiles of Anti-Influenza Agent Isorhapontigenin: A Quantum Chemical and Molecular Docking Study

2021 ◽  
Author(s):  
Sathya Bangaru ◽  
Govindammal M ◽  
Srinivasan M ◽  
Prasath M
2018 ◽  
Vol 11 (3) ◽  
pp. 72 ◽  
Author(s):  
Mayara Teles Fujishima ◽  
Nayara Silva ◽  
Ryan Ramos ◽  
Elenilze Batista Ferreira ◽  
Kelton Santos ◽  
...  

Reactive oxygen species (ROS) are continuously generated in the normal biological systems, primarily by enzymes as xanthine oxidase (XO). The inappropriate scavenging or inhibition of ROS has been considered to be linked with aging, inflammatory disorders, and chronic diseases. Therefore, many plants and their products have been investigated as natural antioxidants for their potential use in preventive medicine. The leaves and bark extracts of Curatella americana Linn. were described in scientific research as anti-inflammatory, vasodilator, anti-ulcerogenic, and hypolipidemic effects. So, the aim of this study was to evaluate the antioxidant potentials of leaf hydroalcoholic extract from C. americana (HECA) through the scavenging DPPH assay and their main chemical constituents, evaluated by the following quantum chemical approaches (DFT B3LYP/6-31G**): Maps of Molecular Electrostatic Potential (MEP), Frontier Orbital’s (HOMO and LUMO) followed by multivariate analysis and molecular docking simulations with the xanthine oxidase enzyme. The hydroalcoholic extract showed significant antioxidant activity by free radical scavenging probably due to the great presence of flavonoids, which were grouped in the PCA and HCA analysis with the standard gallic acid. In the molecular docking study, the compounds studied presented the binding free energy (ΔG) values close each other, due to the similar interactions with amino acids residues at the activity site. The descriptors Gap and softness were important to characterize the molecules with antioxidant potential by capturing oxygen radicals.


Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1393
Author(s):  
Mayra Cristina Martínez-Ceniceros ◽  
Linda-Lucila Landeros-Martínez ◽  
Nora-Aydeé Sánchez-Bojorge ◽  
Fabiola Sandoval-Salas ◽  
Hilda Amelia Piñón-Castillo ◽  
...  

Castor bean (Ricinus Communis) oil has been reported as one of the most important bio-based fuels; however, high amounts of toxic solid residue are generated in the production. This toxicity is due to several molecules, ricin protein being the most studied compound. The inhibition of the ricin protein is essential for eliminating its toxicity. The objective of this study is to predict the possible inhibition process via the interactions between the ricin protein and the flavonoids quercetin (Q) and epigallocatechin gallate (EGCG). The molecular structures of the complexes formed between the ricin protein and flavonoids were studied using quantum-chemical and molecular docking calculations to analyze the type of interaction, active site of the protein, binding energies, and different conformations in the inhibition process. Different methodologies were applied for the molecular structure determination; the best approximation was obtained with B3LYP/6-31G (d,p) theoretical methodology. Mappings of electrostatic potential (MEP) and frontier molecular orbitals were used for the identification of the probable sites of interaction, which were confirmed by molecular docking. The adjustment and alignment of flavonoid groups before and after the interaction, and charge transfer parameters, showed that Q and EGCG act as electron donors inside of the active site in ricin.


2015 ◽  
Author(s):  
Manik Ghosh ◽  
Kamal Kant ◽  
Anoop Kumar ◽  
Padma Behera ◽  
Naresh Rangra ◽  
...  

2020 ◽  
Author(s):  
Rafael Espiritu

<p>Cholesterol-dependent cytolysins (CDCs) are proteinaceous toxins secreted as monomers by some Gram-positive and Gram-negative bacteria that contribute to their pathogenicity. These toxins bind to either cholesterol or human CD59, leading to massive structural changes, toxin oligomerization, formation of very large pores, and ultimately cell death, making these proteins promising targets for inhibition. Myricetin, and its related flavonoids, have been previously identified as a candidate small molecule inhibitor of specific CDCs such as listeriolysin O (LLO) and suilysin (SLY), interfering with their oligomerization. In this work, molecular docking was performed to assess the interaction of myricetin with other CDCs whose crystal structures are already known. Results indicated that although myricetin bound to the hitherto identified cavity in domain 4 (D4), much more efficient and stable binding was obtained in sites along the interfacial regions of domains 1 – 3 (D1 – D3). This was common among the tested CDCs, which was primarily due to much more extensive stabilizing intermolecular interactions, as indicated by post-docking analysis. Specifically, myricetin bound to (1) the interface of the three domains in anthrolysin O (ALO), perfringolysin O (PFO), pneumolysin (PLY), SLY, and vaginolysin (VLY), (2) at/near the D1/D3 interface in LLO and streptolysin O (SLO), and (3) along the D2/D3 interface in intermedilysin (ILY). These findings provide theoretical basis on the possibility of using myricetin and its related compounds as a broad-spectrum inhibitor of CDCs to potentially address the diseases associated with these pathogens.</p>


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