Interaction of 1662G07 analogs with DI/DII.

<p>DI/DII was immobilized on a CM5 sensorchip. Analogs 3-148-1, 3-149-3, 3-149-14, 3-151-2, 3-151-2, 3-151-5, 3-151-4, 3-110-5, 3-110-14 and 3-110-22 were passed over the DI/DII surface at 10, 20 and 40 µM. Background for nonspecific binding to the chip surface was corrected for by passing the analogs over a protein-free channel. All measurements carried out in duplicate.</p

Biochemical, cytotoxicity and antiviral summary of selected compounds from the 3-110 series.

<p>Biochemical, cytotoxicity and antiviral summary of selected compounds from the 3-110 series.</p

Reversibility of antiviral effect.

<p>Viral inocula were preincubated with 1662G07 analogs from the (A) 3-148 and 3-149 and (B) 3-110 series for 10′ at 37°C. DI/DII was then added in molar excess and the incubation continued for an additional 15′. Each inoculum was added to cells, and supernatants were harvested 24 hrs later. An inoculum preincubated with DI/DII alone at the same molar excess showed no loss in viral titre.</p

Proposed mechanism of action of small-molecule inhibitors and postulated equilibrium between two conformations of the sE trimer.

<p>In the “pocket-open", inhibitor-stabilized conformation (right image), the stem-binding groove is absent and the final fusion-inducing step in the conformational change cannot occur. Moreover, sE in this pocket-open conformation would not bind stem-derived peptides. Domains I, II and III are in red, yellow and blue, respectively. All images created with PyMol.</p

Inhibition of Ebola Virus Infection: Identification of Niemann-Pick C1 as the Target by Optimization of a Chemical Probe

A high-throughput screen identified adamantane dipeptide <b>1</b> as an inhibitor of Ebola virus (EboV) infection. Hit-to-lead optimization to determine the structure–activity relationship (SAR) identified the more potent EboV inhibitor <b>2</b> and a photoaffinity labeling agent <b>3</b>. These antiviral compounds were employed to identify the target as Niemann-Pick C1 (NPC1), a host protein that binds the EboV glycoprotein and is essential for infection. These studies establish NPC1 as a promising target for antiviral therapy

Identification of Potent Ebola Virus Entry Inhibitors with Suitable Properties for in Vivo Studies

Previous studies identified an adamantane dipeptide piperazine <b>3.47</b> that inhibits Ebola virus (EBOV) infection by targeting the essential receptor Niemann–Pick C1 (NPC1). The physicochemical properties of <b>3.47</b> limit its potential for testing in vivo. Optimization by improving potency, reducing hydrophobicity, and replacing labile moieties identified <b>3.47</b> derivatives with improved in vitro ADME properties that are also highly active against EBOV infection, including when tested in the presence of 50% normal human serum (NHS). In addition, 3A4 was identified as the major cytochrome P450 isoform that metabolizes these compounds, and accordingly, mouse microsome stability was significantly improved when tested in the presence of the CYP3A4 inhibitor ritonavir that is approved for clinical use as a booster of anti-HIV drugs. Oral administration of the EBOV inhibitors with ritonavir resulted in a pharmacokinetic profile that supports a b.i.d. dosing regimen for efficacy studies in mice

Identification of Potent Ebola Virus Entry Inhibitors with Suitable Properties for in Vivo Studies

Previous studies identified an adamantane dipeptide piperazine <b>3.47</b> that inhibits Ebola virus (EBOV) infection by targeting the essential receptor Niemann–Pick C1 (NPC1). The physicochemical properties of <b>3.47</b> limit its potential for testing in vivo. Optimization by improving potency, reducing hydrophobicity, and replacing labile moieties identified <b>3.47</b> derivatives with improved in vitro ADME properties that are also highly active against EBOV infection, including when tested in the presence of 50% normal human serum (NHS). In addition, 3A4 was identified as the major cytochrome P450 isoform that metabolizes these compounds, and accordingly, mouse microsome stability was significantly improved when tested in the presence of the CYP3A4 inhibitor ritonavir that is approved for clinical use as a booster of anti-HIV drugs. Oral administration of the EBOV inhibitors with ritonavir resulted in a pharmacokinetic profile that supports a b.i.d. dosing regimen for efficacy studies in mice