ABSTRACT
High throughput screening (HTS) of our compound file provided an attractive lead compound with modest P2X(7) receptor antagonist potency and high selectivity against a panel of receptors and channels, but also with high human plasma protein binding and a predicted short half-life in humans. Multi-parameter optimization was used to address the potency, physicochemical and pharmacokinetic properties which led to potent P2X(7)R antagonists with good disposition properties. Compound 33 (CE-224,535) was advanced to clinical studies for the treatment of rheumatoid arthritis.
Subject(s)
Benzamides , Drug Discovery , Purinergic P2 Receptor Antagonists , Receptors, Purinergic P2X7/metabolism , Uracil/analogs & derivatives , Administration, Oral , Animals , Antirheumatic Agents/chemical synthesis , Antirheumatic Agents/chemistry , Antirheumatic Agents/pharmacokinetics , Antirheumatic Agents/pharmacology , Benzamides/chemical synthesis , Benzamides/chemistry , Benzamides/pharmacokinetics , Benzamides/pharmacology , Humans , Inhibitory Concentration 50 , Molecular Structure , Protein Binding/drug effects , Purinergic P2 Receptor Antagonists/chemical synthesis , Purinergic P2 Receptor Antagonists/chemistry , Purinergic P2 Receptor Antagonists/pharmacokinetics , Purinergic P2 Receptor Antagonists/pharmacology , Rats , Structure-Activity Relationship , Uracil/chemical synthesis , Uracil/chemistry , Uracil/pharmacokinetics , Uracil/pharmacologyABSTRACT
The synthesis, structure-activity relationship, in vivo activity, and metabolic profile for a series of triazolopyridine-oxazole based p38 inhibitors are described. The deficiencies of the lead structure in the series, CP-808844, were overcome by changes to the C4 aryl group and the triazole side-chain culminating in the identification of several potential clinical candidates.
Subject(s)
Enzyme Inhibitors/pharmacology , Oxazoles/chemistry , Pyridines/chemistry , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors , p38 Mitogen-Activated Protein Kinases/chemistry , Chemistry, Pharmaceutical , Drug Design , Enzyme Inhibitors/chemistry , Humans , Inhibitory Concentration 50 , Kinetics , Models, Chemical , Solubility , Structure-Activity Relationship , Triazoles/chemistryABSTRACT
Stimulus-induced posttranslational processing of human monocyte interleukin-1beta (IL-1beta) is accompanied by major changes to the intracellular ionic environment, activation of caspase-1, and cell death. Certain diarylsulfonylureas inhibit this response, and are designated cytokine release inhibitory drugs (CRIDs). CRIDs arrest activated monocytes so that caspase-1 remains inactive and plasma membrane latency is preserved. Affinity labeling with [(14)C]CRIDs and affinity chromatography on immobilized CRID were used in seeking potential protein targets of their action. Following treatment of intact human monocytes with an epoxide-bearing [(14)C]CRID, glutathione S-transferase (GST) Omega 1-1 was identified as a preferred target. Moreover, labeling of this polypeptide correlated with irreversible inhibition of ATP-induced IL-1beta posttranslational processing. When extracts of human monocytic cells were chromatographed on a CRID affinity column, GST Omega 1-1 bound selectively to the affinity matrix and was eluted by soluble CRID. Recombinant GST Omega 1-1 readily incorporated [(14)C]CRID epoxides, but labeling was negated by co-incubation with S-substituted glutathiones or by mutagenesis of the catalytic center Cys(32) to alanine. Peptide mapping by high performance liquid chromatography-mass spectrometry also demonstrated that Cys(32) was the site of modification. Although S-alkylglutathiones did not arrest ATP-induced IL-1beta posttranslational processing or inhibit [(14)C]CRID incorporation into cell-associated GST Omega 1-1, a glutathione-CRID adduct effectively demonstrated these attributes. Therefore, the ability of CRIDs to arrest stimulus-induced IL-1beta posttranslational processing may be attributable to their interaction with GST Omega 1-1.
Subject(s)
Glutathione Transferase/metabolism , Interleukin-1/metabolism , Monocytes/metabolism , Adenosine Triphosphate/pharmacology , Amino Acid Sequence , Binding Sites/genetics , Cells, Cultured , Cysteine , Glutathione Transferase/drug effects , Glutathione Transferase/genetics , Humans , Interleukin-1/antagonists & inhibitors , Molecular Sequence Data , Mutagenesis, Site-Directed , Protein Processing, Post-Translational/drug effects , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Sequence AlignmentABSTRACT
The synthesis and in vitro p38 alpha activity of a novel series of benzimidazolone inhibitors is described. The p38 alpha SAR is consistent with a mode of binding wherein the benzimidazolone carbonyl serves as the H-bond acceptor to Met109 of p38 alpha in a manner analogous to the pyridine nitrogen of prototypical pyridylimidazole p38 inhibitors. Potent p38 alpha activity comparable to that of several previously reported p38 inhibitors is observed for this novel chemotype.