The efficacy of the analgesic GlyT2 inhibitor, ORG25543, is determined by two connected allosteric sites.

Glycine Transporter 2 (GlyT2) inhibitors have shown considerable potential as analgesics for the treatment of neuropathic pain but also display considerable side effects. One potential source of side effects is irreversible inhibition. In this study, we have characterized the mechanism of ORG25543 inhibition of GlyT2 by first considering three potential ligand binding sites on GlyT2-the substrate site, the vestibule allosteric site and the lipid allosteric site. The three sites were tested using a combination of molecular dynamics simulations and analysis of the inhibition of glycine transport of a series point mutated GlyT2 using electrophysiological methods. We demonstrate that the lipid allosteric site on GlyT2 is the most likely binding site for ORG25543. We also demonstrate that cholesterol derived from the cell membrane can form specific interactions with inhibitor-bound transporters to form an allosteric network of regulatory sites. These observations will guide the future design of GlyT2 inhibitors with the objective of minimising on-target side effects and improving the therapeutic window for the treatment of patients suffering from neuropathic pain.

Bis(Benzofuran-1,3-N,N-heterocycle)s as Symmetric and Synthetic Drug Leads against Yellow Fever Virus.

The yellow fever virus (YFV) is an emerging RNA virus and has caused large outbreaks in Africa and Central and South America. The virus is often transmitted through infected mosquitoes and spreads from area to area because of international travel. Being an acute viral hemorrhagic disease, yellow fever can be prevented by an effective, safe, and reliable vaccine, but not be eliminated. Currently, there is no antiviral drug available for its cure. Thus, two series of novel bis(benzofuran−1,3-imidazolidin-4-one)s and bis(benzofuran−1,3-benzimidazole)s were designed and synthesized for the development of anti-YFV lead candidates. Among 23 new bis-conjugated compounds, 4 of them inhibited YFV strain 17D (Stamaril) on Huh-7 cells in the cytopathic effect reduction assays. These conjugates exhibited the most compelling efficacy and selectivity with an EC50 of <3.54 µM and SI of >15.3. The results are valuable for the development of novel antiviral drug leads against emerging diseases.

Enterovirus Inhibition by Hinged Aromatic Compounds with Polynuclei.

The modern world has no available drugs for the treatment of enteroviruses (EV), which affect millions of people worldwide each year. The EV71 is a major causative disease for hand, foot, and mouth disease; sometimes it is associated with severe central nervous system diseases. Treatment for enteroviral infection is mainly supportive; treatment for aseptic meningitis caused by enteroviruses is also generally symptomatic. Upon the urgent request of new anti-enterovirus drugs, a series of hinged aromatic compounds with polynulei were synthesized through two different chemical pathways. Among these morpholine-furan/thiophene/pyrrole-benzene-pyrazole conjugates, three new agents exhibited inhibitory activity with EC50 = 2.29-6.16 µM toward EV71 strain BrCr in RD cells. Their selectivity index values were reached as high as 33.4. Their structure-activity relationship was deduced that a thiophene derivative with morpholine and trifluorobenzene rings showed the greatest antiviral activity, with EC50 = 2.29 µM.

A novel multicomponent quadruple/double quadruple domino reaction: highly efficient synthesis of polyheterocyclic architectures.

A novel multicomponent quadruple domino reaction (MCQDR) for the assembly of structurally complex molecular architectures via the formation of three rings and three contiguous stereogenic centers has been accomplished with high regio- and diastereoselectivity. Solvents, catalysts and work-up were not required to obtain the target molecules. In addition, this new protocol is also extended for the multicomponent double quadruple domino reaction (MCDQDR) to create novel polyheterocyclic architectures in an orthogonal manner.

Novel Phenylene Lipids That Are Positive Allosteric Modulators of Glycine Receptors and Inhibitors of Glycine Transporter 2.

Chronic pain is a complex condition that remains resistant to current therapeutics. We previously synthesized a series of N-acyl amino acids (NAAAs) that inhibit the glycine transporter, GlyT2, some of which are also positive allosteric modulators of glycine receptors (GlyRs). In this study, we have synthesized a library of NAAAs that contain a phenylene ring within the acyl tail with the objective of improving efficacy at both GlyT2 and GlyRs and also identifying compounds that are efficacious as dual-acting modulators to enhance glycine neurotransmission. The most efficacious positive allosteric modulator of GlyRs was 2-[8-(2-octylphenyl)octanoylamino]acetic acid (8-8 OPGly) which potentiates the EC5 for glycine activation of GlyRα1 by 1500% with an EC50 of 664 nM. Phenylene-containing NAAAs with a lysine headgroup were the most potent inhibitors of GlyT2 with (2S)-6-amino-2-[8-(3-octylphenyl)octanoylamino]hexanoic acid (8-8 MPLys) inhibiting GlyT2 with an IC50 of 32 nM. The optimal modulator across both proteins was (2S)-6-amino-2-[8-(2-octylphenyl)octanoylamino]hexanoic acid (8-8 OPLys), which inhibits GlyT2 with an IC50 of 192 nM and potentiates GlyRs by up to 335% at 1 µM. When tested in a dual GlyT2/GlyRα1 expression system, 8-8 OPLys caused the greatest reductions in the EC50 for glycine. This suggests that the synergistic effects of a dual-acting modulator cause greater enhancements in glycinergic activity compared to single-target modulators and may provide an alternate approach to the development of new non-opioid analgesics for the treatment of chronic pain.

(E)-2-({2-[(E)-(Hy-droxy-imino)-meth-yl]phen-oxy}meth-yl)-3-phenyl-acrylonitrile.

In the title compound, C(17)H(14)N(2)O(2), the hy-droxy-ethanimine group adopts an anti-periplanar conformation. In the crystal, mol-ecules are linked by O-H⋯N hydrogen bonds, forming zigzag chains running along the c axis.

Identification of Transthyretin Tetramer Kinetic Stabilizers That Are Capable of Inhibiting the Retinol-Dependent Retinol Binding Protein 4-Transthyretin Interaction: Potential Novel Therapeutics for Macular Degeneration, Transthyretin Amyloidosis, and Their Common Age-Related Comorbidities.

Dissociation of transthyretin (TTR) tetramers may lead to misfolding and aggregation of proamyloidogenic monomers, which underlies TTR amyloidosis (ATTR) pathophysiology. ATTR is a progressive disease resulting from the deposition of toxic fibrils in tissues that predominantly presents clinically as amyloid cardiomyopathy and peripheral polyneuropathy. Ligands that bind to and kinetically stabilize TTR tetramers prohibit their dissociation and may prevent ATTR onset. Drawing from clinically investigated AG10, we designed a constrained congener (14) that exhibits excellent TTR tetramer binding potency, prevents TTR aggregation in a gel-based assay, and possesses desirable pharmacokinetics in mice. Additionally, 14 significantly lowers murine serum retinol binding protein 4 (RBP4) levels despite a lack of binding at that protein's all-trans-retinol site. We hypothesize that kinetic stabilization of TTR tetramers via 14 is allosterically hindering all-trans-retinol-dependent RBP4-TTR tertiary complex formation and that the compound could present ancillary therapeutic utility for indications treated with RBP4 antagonists, such as macular degeneration.