Search

An azo-dye lead was modified to a novel N-(1,3-thiazol-2-yl)pyridin-2-amine series of KDR kinase inhibitors through the use of rapid analog libraries. This new class has been found to be potent, selective, and of low molecular weight. Molecular modeling has postulated an interesting conformational preference and binding mode for these compounds in the active site of the enzyme.

We have introduced solubilizing functionality to a 3,6-disubstituted pyrazolo[1,5-a]pyrimidine series of KDR kinase inhibitors to improve the physical properties of these compounds. The addition of a basic side-chain to the 6-aryl ring, introduction of 3-pyridyl groups, and most significantly, incorporation of a 4-pyridinonyl substituent at the 6-position of the core are modifications that maintain and often enhance the intrinsic potency of this class of inhibitors. Moreover, the improvements in physical properties result in marked increases in cellular activity and more favorable pharmacokinetics in rats. The synthesis and SAR of these compounds are described.

The ability to replace an inhibitor bound to the HIV-1 protease in single crystals with other potent inhibitors offers the possibility of investigating a series of protease inhibitors rapidly and conveniently with the use of X-ray crystallography. This approach affords a fast turnaround of structural information for iterative rational drug designs and obviates the need for studying the complex structures by co-crystallization. The replacement approach has been successfully used with single crystals of the HIV-1 protease complexed with a weak inhibitor. The structures of the complexes obtained by the replacement method are similar to those determined by co-crystallization.

A series of analogs of CRIXIVAN® containing various aromatic P1 ligands were prepared and evaluated for inhibition of the HIV-1 protease enzyme. These new compounds were found to be effective inhibitors at nanomolar concentrations in the in vitro enzyme inhibition assay as well as the whole cell assay.

The synsthesis and structure activity relationships of conformationally constrained analogs of the HIV-1 protease inhibitor L-685,434 are described. In addition, the X-ray crystal structure of a complex between L-700,497 and the HIV-1 protease is shown.

A series of analogs of CRIXIVAN® containing various aromatic P1 ligands were prepared and evaluated for inhibition of the HIV-1 protease enzyme. These new compounds were found to be effective inhibitors at nanomolar concentrations in the in vitro enzyme inhibition assay as well as the whole cell assay.

1,5-Diarylbenzimidazoles have been identified as potent inhibitors of KDR kinase activity. The series was developed with a goal of finding compounds with optimal drug-like properties. This communication describes structural modifications in the series that enhance solubility, lower protein binding, and provide compounds with excellent potency and pharmacokinetic profiles.

We have synthesized and evaluated the activity of 3,6-disubstituted pyrazolo[1,5-a]pyrimidines as a new class of KDR kinase inhibitors. Starting with screening lead 1, potency against isolated KDR was fully optimized with 3-thienyl and 4-methoxyphenyl substituents at the 6- and 3-positions (3g, KDR IC(50)=19 nM), respectively. The synthesis and SAR of these compounds are described.

Incorporation of a γ-lactam in hydroxyethylene isosteres results in modest inhibitors of HIV-1 protease. Additional structural activity studies have produced significantly more potent inhibitors with the introduction of the trisubstituted cyclopentane (see compound 20 ) as the optimum substituent for the C-terminus. This new amino acid amide surrogate can be readily prepared in large scale from ( R )-pulegone. Optimized compounds ( 36 ) and ( 60 ) are potent antiviral agents and are well absorbed (15–20 %) in a dog model after oral administration.