Enhancing the antiviral potency of ER α-glucosidase inhibitor IHVR-19029 against hemorrhagic fever viruses in vitro and in vivo.

Targeting host functions essential for viral replication has been considered as a broad spectrum and resistance-refractory antiviral approach. However, only a few host functions have, thus far, been validated as broad-spectrum antiviral targets in vivo. ER α-glucosidases I and II have been demonstrated to be essential for the morphogenesis of many enveloped viruses, including members from four families of viruses causing hemorrhagic fever.

Ester Prodrugs of IHVR-19029 with Enhanced Oral Exposure and Prevention of Gastrointestinal Glucosidase Interaction.

IHVR-19029 () is a lead endoplasmic reticulum α-glucosidases I and II inhibitor, which efficiently protected mice from lethal Ebola and Marburg virus infections via injection route, but suffered from low bioavailability and off-target interactions with gut glucosidases when administered orally. In an effort to improve efficacious exposure levels and avoid side effects, we designed and synthesized ester prodrugs. Not only were the prodrugs stable in simulated gastric and intestinal fluids and were inactive against glucosidases but they also exhibited antiviral activities against dengue virus infection in a cell based assay.

Novel substituted aminothiazoles as potent and selective anti-hepatocellular carcinoma agents.

Based on our previous identification of a disubstituted aminothiazole termed HBF-0079 with promising selective toxicity for HCC-derived cell lines versus non-HCC liver lines, a series of tri-substituted aminothiazole derivatives were prepared and evaluated. This work resulted in the discovery of isopropyl 4-(pyrazin-2-yl)-2-(pyrimidin-2-ylamino)thiazole-5-carboxylate, 14, which displayed EC value of 0.11μM and more than 450times of selectivity, and its methyl carbonate prodrug 24 with improved solubility in organic solvents.

2-[(3aR,4R,5S,7aS)-5-{(1S)-1-[3,5-bis(trifluoromethyl)phenyl]-2-hydroxyethoxy}-4-(2-methylphenyl)octahydro-2H-isoindol-2-yl]-1,3-oxazol-4(5H)-one: a potent human NK1 receptor antagonist with multiple clearance pathways.

Hydroisoindoline 2 has been previously identified as a potent, brain-penetrant NK1 receptor antagonist with a long duration of action and improved profile of CYP3A4 inhibition and induction compared to aprepitant. However, compound 2 is predicted, based on data in preclinical species, to have a human half-life longer than 40 h and likely to have drug-drug-interactions (DDI), as 2 is a victim of CYP3A4 inhibition caused by its exclusive clearance pathway via CYP3A4 oxidation in humans. We now report 2-[(3aR,4R,5S,7aS)-5-{(1S)-1-[3,5-bis(trifluoromethyl)phenyl]-2-hydroxyethoxy}-4-(2-methylphenyl)octahydro-2H-isoindol-2-yl]-1,3-oxazol-4(5H)-one (3) as a next generation NK1 antagonist that possesses an additional clearance pathway through glucuronidation in addition to that via CYP3A4 oxidation.

Tetrahydroindolizinone NK1 antagonists.

A new class of potent NK(1) receptor antagonists with a tetrahydroindolizinone core has been identified. This series of compounds demonstrated improved functional activities as compared to previously identified 5,5-fused pyrrolidine lead structures. SAR at the 7-position of the tetrahydroindolizinone core is discussed in detail.