Fruit Bromelain-Derived Peptide Potentially Restrains the Attachment of SARS-CoV-2 Variants to hACE2: A Pharmacoinformatics Approach

Before entering the cell, the SARS-CoV-2 spike glycoprotein receptor-binding domain (RBD) binds to the human angiotensin-converting enzyme 2 (hACE2) receptor. Hence, this RBD is a critical target for the development of antiviral agents. Recent studies have discovered that SARS-CoV-2 variants with mutations in the RBD have spread globally. The purpose of this in silico study was to determine the potential of a fruit bromelain-derived peptide. DYGAVNEVK. to inhibit the entry of various SARS-CoV-2 variants into human cells by targeting the hACE binding site within the RBD. Molecular docking analysis revealed that DYGAVNEVK interacts with several critical RBD binding residues responsible for the adhesion of the RBD to hACE2. Moreover, 100 ns MD simulations revealed stable interactions between DYGAVNEVK and RBD variants derived from the trajectory of root-mean-square deviation (RMSD), radius of gyration (Rg), and root-mean-square fluctuation (RMSF) analysis, as well as free binding energy calculations. Overall, our computational results indicate that DYGAVNEVK warrants further investigation as a candidate for preventing SARS-CoV-2 due to its interaction with the RBD of SARS-CoV-2 variants.     

In vitro antioxidant and antiproliferative activities of six international basil cultivars

The total phenolic, flavonoid and tannin contents in leaves extracts of Ocimum basilicum (OB) (Lamiaceae) international cultivars, as well as their overall antioxidant activities using DPPH and linoleic acid assays, were investigated. Furthermore, the antiproliferative and cytotoxic activities against line HeLa, MCF-7, Jurkat, HT-29, T24, MIAPaCa-2 cancer cells and one normal human cell line HEK-293 were examined. DPPH and linoleic acid assays ranged from 75.8% to 93.3% and from 74.5% to 97.1%; respectively. O. b. ‘purple ruffle’, O. b. ‘dark opale’, O. b. ‘genovese’, O. b. ‘anise’, O. b. ‘bush green’ and O. b. L. (OBL) varied in their antiproliferative and cytotoxic activities, influenced cell cycle progression and stimulated apoptosis in most cancer cells. OBL exhibited the highest antioxidant and antiproliferative activities. OB extracts not only improve taste but also have certain anticancer activity against diverse cancer cells due to the presence of compounds such as rosmarinic acid, chicoric acid and caftaric acid. Thus, OB represents a potent source of anticancer materials.     

Synthesis and anticancer activity of novel 2-substituted pyranopyridine derivatives

Research on Chemical Intermediates - A novel series of 2-aminopyranopyridine derivatives (3–19) were synthesized utilizing...     

Antimicrobial,antioxidant and antitumor activities of Nano-Structure Eu (III) and La (III) complexes with nitrogen donor tridentate ligands

Nano structure metal complexes of Eu (III) and La (III) with two different nitrogen donor tridentate ligands: N-(2-Aminoethyl)-1,3-propanediamine “AEPD = L1” and 1-(2-Aminoethyl)piperazine “AEPz = L2” , were prepared. All synthesized compounds were identified and confirmed by elemental analyses, molar conductivity and spectral analyses (UV–Visible, IR and mass). Conductance measurement indicates that all the complexes are non-electrolytic in nature and the complexes were isolated in 1:1 molar ratio (metal: ligand). Thermal decomposition profiles were consistent with the proposed formulations. The ligands behave as a tridentate ligand through three nitrogen centers of donation. The nano-size was investigated by using transmission electron microscopy (TEM). The geometric structure properties were analyzed using density functional theory (DFT) for ligands and their Lanthanum (III) complexes. The complexes were screened against some bacteria strains, hepatocellular cell line and diphenylhydrazine free radical. The molecular docking active sites interactions were evaluated.     

Biological Insights of Fluoroaryl-2,2′-Bichalcophene Compounds on Multi-Drug Resistant Staphylococcus aureus

Resistance of bacteria to multiple antibiotics is a significant health problem; hence, to continually respond to this challenge, different antibacterial agents must be constantly discovered. In this work, fluoroaryl-2,2′-bichalcophene derivatives were chemically synthesized and their biological activities were evaluated against Staphylococcus aureus (S. aureus). The impact of the investigated bichalcophene derivatives was studied on the ultrastructural level via scanning electron microscopy (SEM), molecular level via sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) method and on the biofilm inhibition via the electrochemical biosensors. Arylbichalcophenes’ antibacterial activity against S. aureus was affected by the presence and location of fluorine atoms. The fluorobithiophene derivative MA-1156 displayed the best minimum inhibitory concentration (MIC) value of 16 µM among the tested fluoroarylbichalcophenes. Over a period of seven days, S. aureus did not develop any resistance against the tested fluoroarylbichalcophenes at higher concentrations. The impact of fluoroarylbichalcophenes was strong on S. aureus protein pattern showing high degrees of polymorphism. SEM micrographs of S. aureus cells treated with fluoroarylbichalcophenes displayed smaller cell-sizes, fewer numbers, arranged in a linear form and some of them were damaged when compared to the untreated cells. The bioelectrochemical measurements demonstrated the strong sensitivity of S. aureus cells to the tested fluoroarylbichalcophenes and an antibiofilm agent. Eventually, these fluoroarylbichalcophene compounds especially the MA-1156 could be recommended as effective antibacterial agents.     

Synthesis of some novel pyrazolo[1,5-a]quinazolines and their fused derivatives

New pyrazolo[1,5-a]quinazoline-3-carbonitriles 4a,b were obtained via cyclocondensation of 5-amino-3-cyanomethyl-1H-pyrazole-4-carbonitrile (1) with enaminones of 1,3-cyclohexanedione derivatives 2a,b in refluxing glacial acetic acid. Condensation of compounds 4a,b with various aromatic aldehydes furnished the corresponding arylidene derivatives 6a–j. On the other hand, condensation of 4a,b with o-hydroxybenzaldehydes yielded the polyheterocyclic compounds 10a–h. Coupling of compounds 4a,b with aryldiazonium chlorides led to formation of 2-arylhydrazono derivatives 12a–h. Also, reaction of compounds 4a,b with phenyl isothiocyanate, followed by addition of ethyl chloroacetate and chloroacetonitrile, afforded the polyheterocyclic compounds based on pyrazolo[1,5-a]quinazoline core. The reaction of compounds 4a,b with phenyl isothiocyanate and elemental sulfur gave the thiazole-2-thione derivatives 25a,b. The reaction of enamines of compounds 4a,b with each of hydrazine hydrate and guanidine hydrochloride afforded pyrazolo[4″,3″:5′,6′]pyrido[4′,3′:3,4]pyrazolo[1,5-a]quinazolin-8-ones 30a,b and pyrimido[5″,4″:5′,6′]pyrido[4′,3′:3,4]pyrazolo[1,5-a]quinazolin-9(10H)-ones 33a,b, respectively. The structures of all the newly synthesized compounds were elucidated by elemental analyses and spectral data. The plausible mechanisms have been postulated to account for their formation.     

Naproxen derivatives: Synthesis,reactions, and biological applications

This review describes the synthesis and reactions of naproxen derivatives and highlights the effects of compounds containing the naproxen moiety in important biological applications.