Hongying Yun

Discovery of imidazopyridine derivatives as highly potent respiratory syncytial virus fusion inhibitors.

A series of imidazolepyridine derivatives were designed and synthesized according to the established docking studies. The imidazopyridine derivatives were found to have good potency and physical-chemical properties. Several highly potent compounds such as 8ji, 8jl, and 8jm were identified with single nanomolar activities. The most potent compound 8jm showed an IC50 of 3 nM, lower microsome clearance and no CYP inhibition. The profile of 8jm appeared to be superior to BMS433771, and supported further optimization.

Discovery of Piperazinylquinoline Derivatives as Novel Respiratory Syncytial Virus Fusion Inhibitors.

A novel series of piperazinylquinoline derivatives were discovered as respiratory syncytial virus (RSV) fusion inhibitors by the ligand-based screening approach. Among 3,000 hits, 1-amino-3-[[2-(4-phenyl-1-piperidyl)-4-quinolyl]amino]propan-2-ol (7) was proven to be active against the RSV long (A) strain. The anti-RSV activity was improved by converting piperidine to benzylcarbonyl substituted piperazine. The basic side chain was also found to be crucial for anti-RSV activity. The selected analogues, 45 and 50, demonstrated anti-RSV activities up to EC50 = 0.028 μM and 0.033 μM, respectively. A direct anti-RSV effect was confirmed by a plaque reduction assay and a fusion inhibition assay. Both 45 and 50 showed promising DMPK properties with good oral bioavailability, and could potentially lead to novel therapeutic agents targeting the RSV fusion process.

Discovery of Benzoazepinequinoline (BAQ) Derivatives as Novel, Potent, Orally Bioavailable Respiratory Syncytial Virus Fusion Inhibitors

A novel benzoazepinequnoline (BAQ) series was discovered as RSV fusion inhibitors. BAQ series originated from compound 2, a hit from similarity-based virtual screening. In SAR exploration, benzoazepine allowed modifications in the head moiety. Benzylic sulfonyl on benzoazepine and 6-Me on quinoline were crucial for good anti-RSV activity. Although the basic amine in the head portion was crucial for anti-RSV activity, the attenuated basicity was required to reduce Vss. Introducing oxetane to the head portion led to discovery of compound 1, which demonstrated single-digit nM anti-RSV activity against different RSV strains, reasonable oral exposure in plasma, and 78-fold higher exposure in lung. Compound 1 also displayed 1 log viral reduction in a female BALB/c mice RSV model by b.i.d. oral dosing at 12.5 mg/kg. A single resistant mutant at L138F in fusion protein proved compound 1 to be a RSV fusion inhibitor.

Discovery of Small Molecule Therapeutics for Treatment of Chronic HBV Infection

The chronic infection of hepatitis B virus (HBV) inflicts 250 million people worldwide representing a major public health threat. A significant subpopulation of patients eventually develop cirrhosis and hepatocellular carcinoma (HCC). Unfortunately, none of the current standard therapies for chronic hepatitis B (CHB) result in a satisfactory clinical cure rate. Driven by a highly unmet medical need, multiple pharmaceutical companies and research institutions have been engaged in drug discovery and development to improve the CHB functional cure rate, defined by sustainable viral suppression and HBsAg clearance after a finite treatment. This Review summarizes the recent advances in the discovery and development of novel anti-HBV small molecules. It is believed that an improved CHB functional cure rate may be accomplished via the combination of molecules with distinct MoAs. Thus, certain molecules may evolve into key components of a suitable combination therapy leading to superior outcome of clinical efficacy in the future.