ABSTRACT
Inhibition of inducible T-cell kinase (ITK), a nonreceptor tyrosine kinase, may represent a novel treatment for allergic asthma. In our previous reports, we described the discovery of sulfonylpyridine (SAP), benzothiazole (BZT), indazole (IND), and tetrahydroindazole (THI) series as novel ITK inhibitors and how computational tools such as dihedral scans and docking were used to support this process. X-ray crystallography and modeling were applied to provide essential insight into ITK-ligand interactions. However, "visual inspection" traditionally used for the rationalization of protein-ligand affinity cannot always explain the full complexity of the molecular interactions. The fragment molecular orbital (FMO) quantum-mechanical (QM) method provides a complete list of the interactions formed between the ligand and protein that are often omitted from traditional structure-based descriptions. FMO methodology was successfully used as part of a rational structure-based drug design effort to improve the ITK potency of high-throughput screening hits, ultimately delivering ligands with potency in the subnanomolar range.
Subject(s)
Interleukin-2/physiology , Protein Kinase Inhibitors/pharmacology , Protein-Tyrosine Kinases/antagonists & inhibitors , Benzothiazoles/chemistry , Crystallography, X-Ray , Drug Design , Enzyme Induction , Indazoles/chemistry , Models, Molecular , Protein Kinase Inhibitors/chemistry , Protein-Tyrosine Kinases/biosynthesis , Pyridines/chemistry , Quantum TheoryABSTRACT
Starting from benzylpyrimidine 2, molecular modeling and X-ray crystallography were used to design highly potent inhibitors of Interleukin-2 inducible T-cell kinase (ITK). Sulfonylpyridine 4i showed sub-nanomolar affinity against ITK, was selective versus Lck and its activity in the Jurkat cell-based assay was greatly improved over 2.
Subject(s)
Drug Design , Protein Kinase Inhibitors/chemical synthesis , Protein-Tyrosine Kinases/antagonists & inhibitors , Pyridines/chemistry , Binding Sites , Crystallography, X-Ray , Kinetics , Molecular Dynamics Simulation , Protein Binding , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/metabolism , Protein Structure, Tertiary , Protein-Tyrosine Kinases/metabolism , Pyrazoles/chemistry , Pyridines/chemical synthesis , Pyridines/metabolism , Structure-Activity Relationship , Sulfones/chemistryABSTRACT
Interleukin-2 inducible T-cell kinase (ITK), a member of the Tec family of tyrosine kinases, plays a major role in T-cell signaling downstream of the T-cell receptor (TCR), and considerable efforts have been directed toward discovery of ITK-selective inhibitors as potential treatments of inflammatory disorders such as asthma. Using a previously disclosed indazole series of inhibitors as a starting point, and using X-ray crystallography and solubility forecast index (SFI) as guides, we evolved a series of tetrahydroindazole inhibitors with improved potency, selectivity, and pharmaceutical properties. Highlights include identification of a selectivity pocket above the ligand plane, and identification of appropriate lipophilic substituents to occupy this space. This effort culminated in identification of a potent and selective ITK inhibitor (GNE-9822) with good ADME properties in preclinical species.
Subject(s)
Indazoles/chemical synthesis , Protein Kinase Inhibitors/chemical synthesis , Protein-Tyrosine Kinases/antagonists & inhibitors , Animals , Crystallography, X-Ray , Dogs , Drug Design , Humans , Indazoles/pharmacokinetics , Indazoles/pharmacology , Jurkat Cells , Kinetics , Mice , Models, Molecular , Protein Kinase Inhibitors/pharmacokinetics , Protein Kinase Inhibitors/pharmacology , Rats , Solubility , Structure-Activity RelationshipABSTRACT
Inhibition of the non-receptor tyrosine kinase ITK, a component of the T-cell receptor signalling cascade, may represent a novel treatment for allergic asthma. Here we report the structure-based optimization of a series of benzothiazole amides that demonstrate sub-nanomolar inhibitory potency against ITK with good cellular activity and kinase selectivity. We also elucidate the binding mode of these inhibitors by solving the X-ray crystal structures of several inhibitor-ITK complexes.
Subject(s)
Benzothiazoles/chemistry , Benzothiazoles/pharmacology , Protein-Tyrosine Kinases/antagonists & inhibitors , Animals , Benzothiazoles/chemical synthesis , Crystallography, X-Ray , Drug Design , Humans , Mice , Models, Molecular , Protein-Tyrosine Kinases/chemistry , Signal Transduction , Structure-Activity RelationshipABSTRACT
A family of biaryl substituted 1,4-diaminocyclohexanamides of 3-chlorobenzothiophene-2-carboxylic acid is reported as picomolar modulators of Hedgehog protein function. SAR for the 1,4-diaminocyclohexane group is shown to be exquisitely sensitive to substitution on the 4-amino group, and SAR for the 3-chlorobenzothiophene group is highly specific. Preliminary SAR studies of the biaryl substituent led to a picomolar compound with in vivo activity.
Subject(s)
Carboxylic Acids/chemical synthesis , Chemistry, Pharmaceutical/methods , Hedgehog Proteins/agonists , Administration, Oral , Animals , Carboxylic Acids/pharmacology , Cell Line , Drug Design , Hedgehog Proteins/metabolism , Humans , Mice , Models, Biological , Models, Chemical , Stroke/drug therapy , Structure-Activity Relationship , Thiophenes/chemistryABSTRACT
(1,1-Dioxo-2H-[1,2,4]benzothiadiazin-3-yl) azolo[1,5-a]pyridine and azolo[1,5-a]pyrimidine derivatives have been investigated as potential anti-HCV drugs. Their synthesis, HCV NS5B polymerase inhibition, and replicon activity are discussed.
Subject(s)
Antiviral Agents/chemical synthesis , Azoles/chemical synthesis , Benzothiadiazines/chemical synthesis , Enzyme Inhibitors/chemical synthesis , Hepatitis C/drug therapy , Pyridines/chemical synthesis , Pyrimidines/chemical synthesis , Viral Nonstructural Proteins/antagonists & inhibitors , Animals , Antiviral Agents/pharmacology , Azoles/pharmacology , Benzothiadiazines/pharmacology , Chemistry, Pharmaceutical/methods , Drug Design , Enzyme Inhibitors/pharmacology , Hepacivirus/metabolism , In Vitro Techniques , Inhibitory Concentration 50 , Magnetic Resonance Spectroscopy , Models, Chemical , Molecular Structure , Pyridines/pharmacology , Pyrimidines/pharmacology , Structure-Activity Relationship , Viral Nonstructural Proteins/chemistryABSTRACT
[reaction: see text] A synthesis of 28, the carbon framework of the eleutherobin aglycone, is reported in a 15-step sequence from readily available starting materials. The tandem Diels-Alder reaction of 6 and 7 to produce 18, in which three new rings and six new stereocenters are formed, is a key step in the reaction sequence.
Subject(s)
Alkaloids/chemical synthesis , Antineoplastic Agents/chemical synthesis , Diterpenes , Anthozoa/chemistry , Cyclization , Indicators and Reagents , Molecular ConformationABSTRACT
An Mg2+ and ATP dependent beta-lactam synthetase (BLS) catalyses formation of a beta-lactam ring during the biosynthesis of clavulanic acid, an important beta-lactamase inhibitor. An epimeric mixture of a 2-methylated derivative of the natural BLS substrate N2-(2-carboxyethyl)-L-arginine was synthesised and found to be a substrate for the enzyme. The epimeric products were characterised by 1H NMR and mass spectrometric analyses. The results suggest that a modified version of BLS might be used to catalyse the preparation of intermediates useful for the synthesis of beta-lactam antibiotics.
