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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Identification of pyrrolo[3,2-c]pyridin-4-amine compounds as a new class of entry inhibitors against influenza viruses in vitro

Various influenza virus entry inhibitors are being developed as therapeutic antiviral agents in ongoing preparation for emerging influenza viruses, particularly those that may possess drug resistance to the current FDA-approved neuraminidase inhibitors. In this study, small molecules having the pyrrolopyridinamine (PPA), aminothiadiazole (ATD), dihydrofuropyridine carboxamide (HPC), or imidazopyridinamine (IPA) moiety were selected from a target-focused chemical library for their inhibitory activity against influenza A virus by high-throughput screening using the PR8GFP assay. Activity was evaluated by measuring changes the proportion of GFP-expressing cells as a reflection of influenza virus infection. Among them, PPA showed broad-spectrum activity against multiple influenza A viruses and influenza B virus. PPA was found to block the early stages of influenza virus infection using a time-of-addition assay. Using additional phenotypic assays that dissect the virus entry process, it appears that the antiviral activity of PPA against influenza virus can be attributed to interference of the post-fusion process: namely, virus uncoating and nuclear import of viral nucleoprotein complexes. Based on these results, PPA is an attractive chemical moiety that can be used to develop new antiviral drug candidates against influenza viruses. - Highlights: • Four chemical classes are identified from target-focused chemical library by HTS. • PPA inhibits the infection of various influenza A viruses and influenza B virus. • PPA is identified to inhibit the early stages of influenza virus infection. • PPA compound disrupts virus uncoating and nuclear import of viral ribonucleoprotein.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Discovery of imidazo[1,2- a ]-pyridine inhibitors of pan-PI3 kinases that are efficacious in a mouse xenograft model

Alterations in PI3K/AKT signaling are known to be implicated with tumorigenesis. The PI3 kinases family of lipid kinases has been an attractive therapeutic target for cancer treatment. Imidazopyridine compound 1, a potent, selective, and orally available pan-PI3K inhibitor, identified by scaffold morphing of a benzothiazole hit, was further optimized in order to achieve efficacy in a PTEN-deleted A2780 ovarian cancer mouse xenograft model. With a hypothesis that a planar conformation between the core and the 6-heteroaryl ring will allow for the accommodation of larger 5'-substituents in a hydrophobic area under P-loop, SAR efforts focused on 5'-alkoxy heteroaryl rings at the 6-position of imidazopyridine and imidazopyridazine cores that have the same dihedral angle of zero degrees. 6'-Alkoxy 5'-aminopyrazines in the imidazopyridine series were identified as the most potent compounds in the A2780 cell line. Compound 14 with 1,1,1-trifluoroisopropoxy group at 6'-position demonstrated excellent potency and selectivity, good oral exposure in rats and in vivo efficacy in A2780 tumor-bearing mouse. Also, we disclose the X-ray co-crystal structure of one enantiomer of compound 14 in PI3Kα, confirming that the trifluoromethyl group fits nicely in the hydrophobic hot spot under P-loop.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2015

An AlCl 3 based ionic liquid with a neutral substituted pyridine ligand for electrochemical deposition of aluminum

We study a new ionic liquid (IL) based on a neutral ligand, 4-propylpyridine, is obtained via complexation with AlCl 3 . It is found that the asymmetric cleavage of AlCl 3 generates AlCl 2 + and AlCl 4 , and the former is coordinated by 4-Pr-Py to produce the Al-containing cations ([AlCl 2 (4-Pr-Py) 2 ] + ). The AlCl 3 /4-propylpyridine IL with a molar ratio of 1.3/1 is highly fluidic with a viscosity of 42.8 mPa s and an ionic conductivity of 5.0 x 10 -4 S/cm at room temperature. In contrast to conventional ILs for electroplating aluminum in which the electrochemically active species are Al-containing anions (for example Al 2 Cl 7 - ), this new IL has an Al-containing cation as the electroactive species, which is beneficial to electrodeposition of aluminum.

36 MATERIALS SCIENCE↗
DOE OSTI2017

A Pyridine Alkoxide Chelate Ligand That Promotes Both Unusually High Oxidation States and Water-Oxidation Catalysis

Here, water-oxidation catalysis is a critical bottleneck in the direct generation of solar fuels by artificial photosynthesis. Catalytic oxidation of difficult substrates such as water requires harsh conditions, so that the ligand must be designed both to stabilize high oxidation states of the metal center and to strenuously resist ligand degradation. Typical ligand choices either lack sufficient electron donor power or fail to stand up to the oxidizing conditions. This research on Ir-based water-oxidation catalysts (WOCs) has led us to identify a ligand, 2-(2'-pyridyl)-2-propanoate or “pyalk” that fulfills these requirements.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗