(E)-9-(4-Chloro­styr­yl)-3,4,5,6,7,9-hexa­hydro-2H-xanthene-1,8-dione

In the title compound, C21H19ClO3, the two cyclo­hexenone rings adopt half-chair conformations, whereas the pyran ring adopts a boat conformation. The 4-chloro­phenyl ring is almost perpendicular to the plane through the four C atoms of the pyran ring [dihedral angle = 87.97 (6)°]. In the crystal, weak C—H⋯O hydrogen bonds link the mol­ecules into a chain parallel to the a-axis

Structure-activity relationships of fluorene compounds inhibiting HCV variants

Approximately 71 million people suffer from hepatitis C virus (HCV) infection worldwide. Persistent HCV infection causes liver diseases such as chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma, resulting in approximately 400,000 deaths annually. Effective direct-acting antiviral agents (DAAs) have been developed and are currently used for HCV treatment targeting the following three proteins: NS3/4A proteinase that cleaves the HCV polyprotein into various functional proteins, RNA-dependent RNA polymerase (designated as NS5B), and NS5A, which is required for the formation of double membrane vesicles serving as RNA replication organelles. At least one compound inhibiting NS5A is included in current HCV treatment regimens due to the high efficacy and low toxicity of drugs targeting NS5A. Here we report fluorene compounds showing strong inhibitory effects on GT 1b and 3a of HCV. Moreover, some compounds were effective against resistance-associated variants to DAAs. The structure-activity relationships of the compounds were analyzed. Furthermore, we investigated the molecular bases of the inhibitory activities of some compounds by the molecular docking method.11Ysciescopu

Investigation of Molecular Details of Keap1-Nrf2 Inhibitors Using Molecular Dynamics and Umbrella Sampling Techniques

In this study, we investigate the atomistic details of Keap1-Nrf2 inhibitors by in-depth modeling techniques, including molecular dynamics (MD) simulations, and the path-based free energy method of umbrella sampling (US). The protein–protein interaction (PPI) of Keap1-Nrf2 is implicated in several neurodegenerative diseases like cancer, diabetes, and cardiomyopathy. A better understanding of the five sub-pocket binding sites for Nrf2 (ETGE and DLG motifs) inside the Kelch domain would expedite the inhibitor design process. We selected four protein–ligand complexes with distinct co-crystal ligands and binding occupancies inside the Nrf2 binding site. We performed 100 ns of MD simulation for each complex and analyzed the trajectories. From the results, it is evident that one ligand (1VV) has flipped inside the binding pocket, whereas the remaining three were stable. We found that Coulombic (Arg483, Arg415, Ser363, Ser508, and Ser602) and Lennard–Jones (Tyr525, Tyr334, and Tyr572) interactions played a significant role in complex stability. The obtained binding free energy values from US simulations were consistent with the potencies of simulated ligands. US simulation highlight the importance of basic and aromatic residues in the binding pocket. A detailed description of the dissociation process brings valuable insight into the interaction of the four selected protein–ligand complexes, which could help in the future to design more potent PPI inhibitors

9-[(E)-2-(2-Methoxyphenyl)ethenyl]-3,4,5,6,7,9-hexahydro-2H-xanthene-1,8-dione

In the title compound, C22H22O4, the two cyclohexenone rings adopt half-chair conformations, whereas the six-membered pyran ring adopts a flattened boat conformation, with the O and methine C atoms deviating from the plane of the other four atoms by 0.142 (2) and 0.287 (2)Å, respectively. In the crystal, weak C—H...O hydrogen bonds link molecules into chains running parallel to the a axis

Glutamate Permeability of Chicken Best1

Copyright © Experimental Neurobiology 2022.Bestrophin-1 (Best1) is a calcium (Ca2+)-activated chloride (Cl-) channel which has a phylogenetically conserved channel structure with an aperture and neck in the ion-conducting pathway. Mammalian mouse Best1 (mBest1) has been known to have a permeability for large organic anions including gluconate, glutamate, and D-serine, in addition to several small monovalent anions, such as Cl-, bromine (Br-), iodine (I-), and thiocyanate (SCN-). However, it is still unclear whether non-mammalian Best1 has a glutamate permeability through the ion-conducting pathway. Here, we report that chicken Best1 (cBest1) is permeable to glutamate in a Ca2+-dependent manner. The molecular docking and molecular dynamics simulation showed a glutamate binding at the aperture and neck of cBest1 and a glutamate permeation through the ion-conducting pore, respectively. Moreover, through electrophysiological recordings, we calculated the permeability ratio of glutamate to Cl- (PGlutamate/PCl) as 0.28 based on the reversal potential shift by ion substitution from Cl- to glutamate in the internal solution. Finally, we directly detected the Ca2+-dependent glutamate release through cBest1 using the ultrasensitive two-cell sniffer patch technique. Our results propose that Best1 homologs from non-mammalian (cBest1) to mammalian (mBest1) have a conserved permeability for glutamate.11Nsciescopuskc

Antioxidant and Anti-Inflammatory Activities of a Natural Compound, Shizukahenriol, through Nrf2 Activation

Imbalance in the antioxidant defense system leads to detrimental consequences, such as neurological disorders. The Nrf2 signaling is known as a main pathway involved in cellular defense system. Nrf2 is a transcription factor that regulates oxidative stress response by inducing expression of various antioxidant enzyme genes. In this study, we screened several pure natural compounds for Nrf2 activator. Among them, shizukahenriol (SZH), isolated from Chloranthus henryi, activated Nrf2, and induced expression of the Nrf2-dependent antioxidant enzymes HO-1, GCLC, and GCLM in BV-2 microglial cells. This natural compound was also effective in suppressing production of inflammatory molecules NO, TNF-α, and inhibition of NF-κB p65 translocation to the nucleus in a dose-dependent manner. We also examined whether SZH rescued the microglial cells from oxidative stress-induced cell death. Pretreatment with SZH dose-dependently attenuated H2O2-induced cytotoxicity in BV-2 microglial cells. These results suggested SZH as a potential neuroprotective agent for neurological disorders

Receptor–Ligand Interaction-Based Virtual Screening for Novel Eg5/Kinesin Spindle Protein Inhibitors

Eg5/KSP is a promising mitotic spindle target for drug discovery in cancer chemotherapy and the development of agents against fungal diseases. A range of Eg5 targeting compounds identified by in vitro or cell-based screening is currently in development. We employed structure-based virtual screening of a database of 700 000 compounds to identify three novel Eg5 inhibitors bearing quinazoline (<b>24</b>) or thioxoimidazolidine (<b>30</b> and <b>37</b>) scaffolds. The new compounds inhibit Eg5 ATPase activity, show growth inhibition in proliferation assays, and induce monoastral spindles in cells, the characteristic phenotype for Eg5 inhibiting agents. This is the first successful reported procedure for the identification of Eg5 inhibitors via receptor–ligand interaction-based virtual screening