ABSTRACT
The discovery and development of a series of thiophenes as potent and selective inhibitors of PLK is described. Identification and characterization of 2, a useful in vitro PLK inhibitor tool compound, is also presented.
Subject(s)
Cell Cycle Proteins/antagonists & inhibitors , Chemistry, Pharmaceutical/methods , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Proto-Oncogene Proteins/antagonists & inhibitors , Thiophenes/antagonists & inhibitors , Animals , Cell Cycle , Cell Cycle Proteins/chemistry , Cell Line, Tumor , Cell Proliferation , Drug Design , Humans , Inhibitory Concentration 50 , Mice , Mitosis , Models, Chemical , Molecular Conformation , Protein Serine-Threonine Kinases/chemistry , Proto-Oncogene Proteins/chemistry , Thiophenes/chemistry , Polo-Like Kinase 1ABSTRACT
A series of pyrazolo[1,5-a]pyridine derivatives was designed and synthesized as novel potent p38 kinase inhibitors. Our approaches towards improving in vitro metabolism and in vivo pharmacokinetic properties of the series are described.
Subject(s)
Chemistry, Pharmaceutical/methods , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacokinetics , Pyridines/chemical synthesis , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors , Animals , Anti-Inflammatory Agents/chemical synthesis , Anti-Inflammatory Agents/pharmacology , Area Under Curve , Dogs , Drug Design , Humans , Inhibitory Concentration 50 , Leukocytes, Mononuclear/drug effects , MAP Kinase Signaling System , Pyridines/pharmacokinetics , Rats , Structure-Activity Relationship , p38 Mitogen-Activated Protein Kinases/metabolismABSTRACT
[reaction: see text] A convergent synthesis of substituted pyrazolo[1,5-a]pyridines has been achieved either via a regioselective [3 + 2] cycloaddition of N-aminopyridines with alkynes or by thermal cyclization of disubstituted azirines. Subsequent palladium-catalyzed introduction of pyridines or de novo synthesis of pyrimidines affords inhibitors of p38 kinase.
Subject(s)
Protein Kinase Inhibitors/chemistry , Pyrazoles/chemistry , Pyridines/chemistry , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors , Crystallography, X-Ray , Molecular Structure , Protein Kinase Inhibitors/pharmacology , Pyrazoles/pharmacology , Pyridines/pharmacology , Structure-Activity RelationshipABSTRACT
We report a systematic analysis of the P1' and P2' substrate specificity of TNF-alpha converting enzyme (TACE) using a peptide library and a novel analytical method, and we use the substrate specificity information to design novel reverse hydroxamate inhibitors. Initial truncation studies, using the amino acid sequence around the cleavage site in precursor-TNF-alpha, showed that good turnover was obtained with the peptide DNP-LAQAVRSS-NH2. Based on this result, 1000 different peptide substrates of the form Biotin-LAQA-P1'-P2'-SSK(DNP)-NH2 were prepared, with 50 different natural and unnatural amino acids at P1' in combination with 20 different amino acids at P2'. The peptides were pooled, treated with purified microsomal TACE, and the reaction mixtures were passed over a streptavidin affinity column to remove unreacted substrate and the N-terminal biotinylated product. C-terminal cleavage products not binding to streptavidin were subjected to liquid chromatography/mass spectrometry analysis where individual products were identified and semiquantitated. 25 of the substrates were resynthesized as discrete peptides and assayed with recombinant TACE. The experiments show that recombinant TACE prefers lipophilic amino acids at the P1' position, such as phenylglycine, homophenylalanine, leucine and valine. At the P2' position, TACE can accommodate basic amino acids, such as arginine and lysine, as well as certain non-basic amino acids such as citrulline, methionine sulfoxide and threonine. These substrate preferences were used in the design of novel reverse hydroxamate TACE inhibitors with phenethyl and 5-methyl-thiophene-methyl side-chains at P1', and threonine and nitro-arginine at P2'.
