Application of Virtual Screening to the Identification of New LpxC Inhibitor Chemotypes, Oxazolidinone and Isoxazoline

This report summarizes the identification and synthesis of novel LpxC inhibitors aided by computational methods that leveraged numerous crystal structures. This effort led to the identification of oxazolidinone and isoxazoline inhibitors with potent in vitro activity against P. aeruginosa and other Gram-negative bacteria. Representative compound 13f demonstrated efficacy against P. aeruginosa in a mouse neutropenic thigh infection model. The antibacterial activity against K. pneumoniae could be potentiated by Gram-positive antibiotics rifampicin (RIF) and vancomycin (VAN) in both in vitro and in vivo models.

Potent nonimmunosuppressive cyclophilin inhibitors with improved pharmaceutical properties and decreased transporter inhibition

Nonimmunosuppressive cyclophilin inhibitors have demonstrated efficacy for the treatment of hepatitis C infection (HCV). However, alisporivir, cyclosporin A, and most other cyclosporins are potent inhibitors of OATP1B1, MRP2, MDR1, and other important drug transporters. Reduction of the side chain hydrophobicity of the P4 residue preserves cyclophilin binding and antiviral potency while decreasing transporter inhibition. Representative inhibitor 33 (NIM258) is a less potent transporter inhibitor relative to previously described cyclosporins, retains anti-HCV activity in cell culture, and has an acceptable pharmacokinetic profile in rats and dogs. An X-ray structure of 33 bound to rat cyclophilin D is reported.

2-Alkyloxazoles as potent and selective PI4KIIIβ inhibitors demonstrating inhibition of HCV replication

Synthesis and SAR of 2-alkyloxazoles as class III phosphatidylinositol-4-kinase beta (PI4KIIIβ) inhibitors is described. These compounds demonstrate that inhibition of PI4KIIIβ leads to potent inhibition of HCV replication as observed in genotype (GT) 1a and 1b replicon and GT2a JFH1 virus assays in vitro.

A Catalytic Reaction of Alkynes via Multiple-Site Functionalization

The first multiple-site activation of alkynes with amine/halogen functionalities has been established. The reaction was performed by treating alkyne with N,N-dichlorobenzenesulfonamide at 80 degrees C in the presence of palladium acetate catalyst. A new mechanism was proposed which involves the novel formation of beta-halovinyl palladium and pi-allylpalladium species. Excellent regio- and stereoselectivities were achieved with the absolute structure determined by X-ray structural analysis.