ABSTRACT
Lck, or lymphocyte specific kinase, is a cytoplasmic tyrosine kinase of the Src family expressed in T-cells and NK cells. Genetic evidence from knockout mice and human mutations demonstrates that Lck kinase activity is critical for T-cell receptor-mediated signaling, leading to normal T-cell development and activation. A small molecule inhibitor of Lck is expected to be useful in the treatment of T-cell-mediated autoimmune and inflammatory disorders and/or organ transplant rejection. In this paper, we describe the structure-guided design, synthesis, structure-activity relationships, and pharmacological characterization of 2-amino-6-phenylpyrimido[5',4':5,6]pyrimido[1,2- a]benzimidazol-5(6 H)-ones, a new class of compounds that are potent inhibitors of Lck. The most promising compound of this series, 6-(2,6-dimethylphenyl)-2-((4-(4-methyl-1-piperazinyl)phenyl)amino)pyrimido[5',4':5,6]pyrimido-[1,2- a]benzimidazol-5(6 H)-one ( 25), exhibits potent inhibition of Lck kinase activity. This activity translates into inhibition of in vitro cell-based assays and in vivo models of T-cell activation and arthritis, respectively.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/chemical synthesis , Arthritis/drug therapy , Benzimidazoles/chemical synthesis , Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/antagonists & inhibitors , Protein Kinase Inhibitors/chemical synthesis , Pyrimidinones/chemical synthesis , Administration, Oral , Animals , Anti-Inflammatory Agents, Non-Steroidal/chemistry , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Benzimidazoles/chemistry , Benzimidazoles/pharmacology , Crystallography, X-Ray , Disease Models, Animal , Drug Design , Drug Evaluation, Preclinical , Enzyme Activation/drug effects , Female , Injections, Intradermal , Interleukin-2/metabolism , Male , Mice , Mice, Inbred BALB C , Models, Molecular , Molecular Structure , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Pyrimidinones/chemistry , Pyrimidinones/pharmacology , Rats , Rats, Inbred Lew , Rats, Sprague-Dawley , Reproducibility of Results , Stereoisomerism , Structure-Activity Relationship , T-Lymphocytes/drug effects , T-Lymphocytes/metabolismABSTRACT
The lymphocyte-specific kinase (Lck) is a cytoplasmic tyrosine kinase of the Src family expressed in T cells and NK cells. Genetic evidence in both mice and humans demonstrates that Lck kinase activity is critical for signaling mediated by the T cell receptor (TCR), which leads to normal T cell development and activation. A small molecule inhibitor of Lck is expected to be useful in the treatment of T cell-mediated autoimmune and inflammatory disorders and/or organ transplant rejection. In this paper, we describe the synthesis, structure-activity relationships, and pharmacological characterization of 2-aminopyrimidine carbamates, a new class of compounds with potent and selective inhibition of Lck. The most promising compound of this series, 2,6-dimethylphenyl 2-((3,5-bis(methyloxy)-4-((3-(4-methyl-1-piperazinyl)propyl)oxy)phenyl)amino)-4-pyrimidinyl(2,4-bis(methyloxy)phenyl)carbamate (43) exhibits good activity when evaluated in in vitro assays and in an in vivo model of T cell activation.
Subject(s)
Aminopyridines/chemical synthesis , Anti-Inflammatory Agents/chemical synthesis , Carbamates/chemical synthesis , Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/antagonists & inhibitors , Pyrimidines/chemical synthesis , Administration, Oral , Aminopyridines/chemistry , Aminopyridines/pharmacology , Animals , Anti-Inflammatory Agents/chemistry , Anti-Inflammatory Agents/pharmacology , Biological Availability , Carbamates/chemistry , Carbamates/pharmacology , Crystallography, X-Ray , Humans , In Vitro Techniques , Jurkat Cells , Lymphocyte Activation , Lymphocyte Culture Test, Mixed , Mice , Mice, Inbred BALB C , Models, Molecular , Molecular Structure , Pyrimidines/chemistry , Pyrimidines/pharmacology , Rats , Rats, Sprague-Dawley , Structure-Activity Relationship , T-Lymphocytes/drug effects , T-Lymphocytes/immunologyABSTRACT
2,3-Diarylfuro[2,3-b]pyridine-4-amines are a novel class of potent and selective inhibitors of Lck. The discovery, synthesis, and structure activity relationships of this series of inhibitors are reported. The most promising compounds were also profiled to deduce their pharmacokinetic properties.
Subject(s)
Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/antagonists & inhibitors , Pyridines/chemical synthesis , Pyridines/pharmacokinetics , Amines/chemical synthesis , Amines/pharmacokinetics , Animals , Humans , Inhibitory Concentration 50 , Pharmacokinetics , Protein Kinase Inhibitors/chemical synthesis , Protein Kinase Inhibitors/pharmacokinetics , Rats , Rats, Sprague-Dawley , Structure-Activity RelationshipABSTRACT
4-Amino-5,6-biaryl-furo[2,3-d]pyrimidines were identified as potent non-selective inhibitors of Lck. A novel, divergent, and practical synthetic route was developed to access derivatives from bifunctional intermediates. Lead optimization was guided by X-ray crystallographic data, and preliminary SAR led to the identification of compounds with improved cellular potency and selectivity.