19056-79-2Relevant articles and documents
GABAa receptor ligands often interact with binding sites in the transmembrane domain and in the extracellular domain—can the promiscuity code be cracked?
Ernst, Margot,Iorio, Maria Teresa,Koniuszewski, Filip,Mihovilovic, Marko D.,Rehman, Sabah,Schnürch, Michael,Scholze, Petra,Simeone, Xenia,Vogel, Florian Daniel
, (2020)
Many allosteric binding sites that modulate gamma aminobutyric acid (GABA) effects have been described in heteropentameric GABA type A (GABAA) receptors, among them sites for benzodiazepines, pyrazoloquinolinones and etomidate. Diazepam not only binds at the high affinity extracellular “canonical” site, but also at sites in the transmembrane domain. Many ligands of the benzodiazepine binding site interact also with homologous sites in the extracellular domain, among them the pyrazoloquinolinones that exert modulation at extracellular α+/β? sites. Additional interaction of this chemotype with the sites for etomidate has also been described. We have recently described a new indole‐based scaffold with pharmacophore features highly similar to pyrazoloquinolinones as a novel class of GABAA receptor modulators. Contrary to what the pharmacophore overlap suggests, the ligand presented here behaves very differently from the identically substituted pyrazoloquinolinone. Structural evidence demonstrates that small changes in pharmacophore features can induce radical changes in ligand binding properties. Analysis of published data reveals that many chemotypes display a strong tendency to interact promiscuously with binding sites in the transmembrane domain and others in the extracellular domain of the same receptor. Further structural investigations of this phenomenon should enable a more targeted path to less promiscuous ligands, potentially reducing side effect liabilities.
Crystal Packing Modulation of the Strength of Resonance-Assisted Hydrogen Bonds and the Role of Resonance-Assisted Pseudoring Stacking in Geminal Amido Esters: Study Based on Crystallography and Theoretical Calculations
Venkatesan, Perumal,Thamotharan, Subbiah,Percino, M. Judith,Ilangovan, Andivelu
, p. 779 - 798 (2021/01/13)
A detailed experimental and theoretical investigation of a series of substituted geminal amido esters (ethyl (2E)-3-(arylamino)-2-(arylcarbamoyl)prop-2-enoate, AME-1-8) leading to the identification of a unique angularly fused pseudotricyclic (S(6),S(6),S(6)) ring system stabilized by an intramolecular resonance-assisted hydrogen bond (RAHB) and a non-RAHB are presented in addition to weak intermolecular interactions. An analysis of X-ray and theoretical models reveals that the strength of the intramolecular RAHB (N1-H1N···O1) varies in a wide range (6.9-11.4 kcal mol-1) due to crystal-packing constraints arising from different aromatic ring substitutions. However, the effect is less significant and the strength differs only in a narrow range (8.2-9.9 kcal mol-1) in the case of non-RAHB. The downfield shift (δ～12.3) observed for the N-Haniline signal in 1H NMR spectra of AME-1-8 is due to the presence of intramolecular RAHB. A PIXEL energy analysis suggests that the molecular dimer formed by stacking of RAHB pseudorings is found to be strong (Etot = -14.4 to -17.9 kcal mol-1), and this dimer forms the basic motif in most of the structures reported herein. A detailed analysis of the isostructurality suggests that the basic motif exists in most of the structural combinations. The weak intermolecular C-H···O, C-H···Cl, and C-H···πinteractions play a vital role in the stabilization of these crystal structures, as evaluated by PIXEL and Bader's quantum theory of atoms in molecules approach (QTAIM). A lattice energy analysis suggests that the Coulombic contribution and total lattice energies are higher in the para-substituted compounds (AME-2, AME-5, and AME-8) in comparison to the other isomeric compounds. Further, the crystal packing of these compounds is analyzed on the basis of the energy frameworks. It shows that most of the crystals show similar 3D topologies, suggesting that these compounds may have similar mechanical behavior.
Design, synthesis, in vitro and in silico studies of novel 4-oxoquinoline ribonucleoside derivatives as HIV-1 reverse transcriptase inhibitors
Forezi, Luana da S.M.,Ribeiro, Mariana M.J.,Marttorelli, Andressa,Abrantes, Juliana L.,Rodrigues, Carlos R.,Castro, Helena Carla,Souza, Thiago Moreno L.,Boechat, Fernanda da C.S.,de Souza, Alessandra M.T.,de Souza, Maria Cecília B.V.
, (2020/04/02)
Human immunodeficiency virus type 1 (HIV-1) is a public health problem that affects over 38 million people worldwide. Although there are highly active antiretroviral therapies, emergence of antiviral resistant strains is a problem which leads to almost a million death annually. Thus, the development of new drugs is necessary. The viral enzyme reverse transcriptase (RT) represents a validated therapeutic target. Because the oxoquinolinic scaffold has substantial biological activities, including antiretroviral, a new series of 4-oxoquinoline ribonucleoside derivatives obtained by molecular hybridization were studied here. All synthesized compounds were tested against human immunodeficiency virus type 1 reverse transcriptase (HIV-1 RT), and 9a and 9d displayed the highest antiviral activities, with IC50 values of 1.4 and 1.6 μM, respectively. These compounds were less cytotoxic than AZT and showed CC50 values of 1486 and 1394 μM, respectively. Molecular docking studies showed that the most active compounds bound to the allosteric site of the enzyme, suggesting a low susceptibility to the development of antiviral resistance. In silico pharmacokinetic and toxicological evaluations reinforced the potential of the active compounds as anti-HIV candidates for further exploration. Overall, this work showed that compounds 9a and 9d are promising scaffold for future anti-HIV-1 RT drug design.
