Investigation of angucycline compounds as potential drug candidates against SARS Cov-2 main protease using docking and molecular dynamic approaches

Molecular Diversity - The emerged Coronavirus disease (COVID-19) causes severe or even fatal respiratory tract infection, and to date there is no FDA-approved therapeutics or effective treatment...     

Reactions within association complexes: the reaction of imidazole with substituted phenyl acetates in the presence of detergents in aqueous solution

The bimolecular rate constants for reaction of imidazole with phenyl acetates complexed with sodium dodecyl sulfate (SDS) or cetyltrimethylammonium bromide (CTAB) micelles obey Bronsted equations with beta 1g similar to that of the reaction in aqueous solution. The dissociation constants of ester (Ks) and the hypothetical dissociation constant (KTS) of the transition state of the micelle complexes obey Hansch equations with similar sensitivities (p) to pi (-0.66 and -0.589 for KS and -0.735 and -0.495 for KTS, respectively). The slopes also indicate that the microsolvation environments associated with the transition state and the complexed ester have aqueous character. The relative values of KTS and KS indicate that the transition state of the reaction of imidazole with ester is more weakly complexed to both micelles than is the reactant ester. Log KTS values are linear functions of log KS for reactions with both CTAB and SDS; the slopes are, respectively, -0.893 and -1.19 consistent with a slightly more "water-like" medium for the transition state than for the site of binding of ester with CTAB-micelle and slightly less for the SDS-micelle. The results for ester and transition state are consistent with the location of the phenyl residue in a hydrophobic region that possesses water molecules. It is concluded that the acetyl group in the complexed transition state is located in an aqueous part of the Stern region, whereas the phenyl residue is in a part of the Stern region that possesses alkane components. The derived kinetic and complexation parameters in these experiments refer to micelles with Stern regions that have been maintained at constant ionic compositions.     

Gravitational Frames and Scalar Field Dynamics

Scalar fields describe interesting phenomena such as Higgs bosons, dark matter and dark energy, and are found to be quite common in physical theories. These fields are susceptible to gravitational forces so that being massless is not enough to remain conformal invariant. They should also be connected directly to the scalar curvature. Because of this characteristics, we investigated the structure and interactions of scalar fields under the conformal transformations. We show how to reduce the quadratic quantum contributions in the single scalar field theory. In the multi-scalar field theories, we analyzed interactions in certain limits. We suggest a new method for stabilizing Higgs bosons.