ABSTRACT
Zeta-associated protein, 70 kDa (ZAP-70), a spleen tyrosine kinase (Syk) family kinase, is normally expressed on T cells and natural killer cells and plays a crucial role in activation of the T cell immunoresponse. Thus, selective ZAP-70 inhibitors might be useful not only for treating autoimmune diseases, but also for suppressing organ transplant rejection. In our recent study on the synthesis of Syk family kinase inhibitors, we discovered that novel imidazo[1,2-c]pyrimidine-8-carboxamide derivatives possessed potent ZAP-70 inhibitory activity with good selectivity for ZAP-70 over other kinases. In particular, compound 26 showed excellent ZAP-70 kinase inhibition and high selectivity for ZAP-70 over structurally related Syk. The discovery of a potent, highly selective ZAP-70 inhibitor would contribute a new therapeutic tool for autoimmune diseases and organ transplant medication.
Subject(s)
Protein Kinase Inhibitors/chemical synthesis , Pyrimidines/chemical synthesis , Pyrimidines/pharmacology , ZAP-70 Protein-Tyrosine Kinase/antagonists & inhibitors , Amides , Benzene Derivatives , Humans , Immunity , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Structure-Activity Relationship , ZAP-70 Protein-Tyrosine Kinase/immunologyABSTRACT
The interaction energy was calculated, by the ab initio FMO method, for complexes between LCK protein and four inhibitors (staurosporine, BMS compound 2, and our compounds 3 and 4). In every case a number of CH/pi hydrogen bonds have been disclosed in the so-called adenine pocket. In complexes of 2, 3, and 4, CH/pi and NH/pi hydrogen bonds have been observed in another pocket. In view of the above results, the aniline ring of 3 was replaced by 2,6-dimethyl aniline to increase the potency for LCK kinase. A 10-fold increase in the potency has been achieved for 4 over 3. We suggest that the concept of weak hydrogen bonds is useful in the rational design of drugs.
Subject(s)
Drug Design , Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/chemistry , Protein Kinase Inhibitors/chemistry , Electrons , Hydrogen Bonding , Models, Molecular , Molecular Structure , Protein Conformation , Protein Structure, Tertiary , Structure-Activity Relationship , ThermodynamicsABSTRACT
Spleen tyrosine kinase (Syk) and zeta-associated protein kinase of 70k Da (ZAP-70) are members of the Syk family and non-receptor-type protein tyrosine kinases, which play crucial roles in B- and T-cell activation. Therefore, a Syk family tyrosine kinases inhibitor would be a useful therapeutic agent for the treatment of various allergic disorders and autoimmune diseases. Previously, we reported that 1,2,4-triazolo[4,3-c]pyrimidine derivative 1 and 1,2,4-triazolo[1,5-c]pyrimidine derivative 2 showed strong inhibitory activities against Syk family kinases. These compounds also exhibited high-level suppression of IL-2 in cellular assays. However, their oral efficacies were poor in a mouse model of IL-2 production. To improve oral effectiveness, we investigated a new series of Syk family kinases inhibitors. We found that imidazo[1,2-c]pyrimidine derivatives potently inhibited the Syk family kinases. Among these agents, compound 9f not only showed strong inhibitory activities against Syk and ZAP-70 kinases in vitro, but its oral administration resulted in the in vivo suppression of both the passive cutaneous anaphylaxis reaction and Concanavalin A-induced IL-2 production in a mouse model.
Subject(s)
Imidazoles/chemistry , Intracellular Signaling Peptides and Proteins/antagonists & inhibitors , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/chemical synthesis , Protein-Tyrosine Kinases/antagonists & inhibitors , Pyrimidines/administration & dosage , Pyrimidines/chemical synthesis , Administration, Oral , Animals , Crystallography, X-Ray , Enzyme Activation/drug effects , Humans , Inhibitory Concentration 50 , Intracellular Signaling Peptides and Proteins/classification , Intracellular Signaling Peptides and Proteins/metabolism , Mice , Mice, Inbred ICR , Models, Molecular , Molecular Structure , Protein Kinase Inhibitors/chemistry , Protein-Tyrosine Kinases/classification , Protein-Tyrosine Kinases/metabolism , Pyrimidines/chemistry , Structure-Activity Relationship , Syk Kinase , ZAP-70 Protein-Tyrosine Kinase/antagonists & inhibitors , ZAP-70 Protein-Tyrosine Kinase/metabolismABSTRACT
A series of novel and potent 3-amidinophenylsulfonamide derivatives of factor Xa inhibitors were designed and synthesized using an amidoxime prodrug strategy. We focused on systemic clearance of parent compounds in rats, and performed in vivo pharmacokinetic screening. Incorporation of a carboxymethoxy group markedly improved systemic clearance (compound 43), and the related amidoxime 44 showed sufficient prodrug conversion. Compound 45, the double prodrug of 43, exhibited practicable bioavailability after oral administration in rats. Among the various compounds under investigation, KFA-1982 was selected for clinical development.
Subject(s)
Amidines/chemical synthesis , Enzyme Inhibitors/administration & dosage , Enzyme Inhibitors/pharmacology , Factor Xa Inhibitors , Sulfonamides/chemical synthesis , Sulfonamides/pharmacology , Administration, Oral , Amidines/pharmacology , Animals , Biological Availability , Chemistry, Pharmaceutical/methods , Drug Design , Humans , Mice , Models, Chemical , Molecular Structure , Oximes/chemistry , Prodrugs/chemistry , Trypsin/chemistryABSTRACT
Splenic tyrosine kinase (Syk) family kinases, which are members of the protein tyrosine kinase family, play crucial roles in immune responses, with Syk participating in B-cell activation and the zeta-associated protein 70 kDa (ZAP-70) kinase being involved in T-cell activation. Therefore, Syk family kinase inhibitors are candidate therapeutic agents for the treatment of various allergic disorders and autoimmune diseases. We designed 1,2,4-triazolo[4,3-c]pyrimidine and 1,2,4-triazolo[1,5-c]pyrimidine derivatives as Syk family kinase inhibitors, based on literature reports and structure-based drug design. These derivatives showed significant Syk inhibitory activities, with ZAP-70 inhibition. Representative compounds 10d and 11 not only exhibited strong inhibition of both Syk and ZAP-70 kinase but also suppressed IL-2 production by peripheral blood mononuclear cells and whole blood.
Subject(s)
Intracellular Signaling Peptides and Proteins/antagonists & inhibitors , Protein-Tyrosine Kinases/antagonists & inhibitors , Pyrimidines/chemistry , Pyrimidines/pharmacology , Binding Sites , Drug Design , Humans , Interleukin-1/metabolism , Leukocytes/drug effects , Leukocytes/metabolism , Models, Molecular , Molecular Structure , Structure-Activity Relationship , Syk KinaseABSTRACT
To improve the in vitro potency of the c-Src inhibitor 1a and to address its hERG liability, a structure-activity study was carried out, focusing on two regions of the lead compound. The blockade of the delayed cardiac current rectifier K(+) (I(Kr)) channel was overcome by replacing the ethylenediamino group with an amino alcohol group at the 7-position. In addition, modifying the substituents at the 5-position and the side chain groups on the amino alcohols at the 7-position enhanced the intracellular c-Src inhibitory activity and increased central nervous system (CNS) penetration. In the present study, 6l exhibited significant in vivo efficacy in a middle cerebral artery (MCA) occlusion model in rats.
Subject(s)
Potassium Channel Blockers/pharmacology , Pyrazoles , Pyrimidines , src-Family Kinases/antagonists & inhibitors , Animals , Combinatorial Chemistry Techniques , Middle Cerebral Artery/drug effects , Models, Molecular , Molecular Conformation , Molecular Structure , Pyrazoles/chemical synthesis , Pyrazoles/chemistry , Pyrazoles/pharmacology , Pyrimidines/chemical synthesis , Pyrimidines/chemistry , Pyrimidines/pharmacology , RatsABSTRACT
We synthesized a series of novel 2-anilinopyrazolo[1,5-a]pyrimidine derivatives and evaluated their ability to inhibit c-Src kinase; 7-(2-amino-2-methylpropylamino)-5-cyclopropyl-2-(3,5-dimethoxyphenylamino)pyrazolo[1,5-a]pyrimidine-3-carboxamide 7o and 7-(2-amino-2-methylpropylamino)-2-(3,5-dimethoxyphenylamino)-5-methylpyrazolo[1,5-a]pyrimidine-3-carboxamide 7f showed potent inhibitory activity. Compound 7f inhibited c-Src selectively and exhibited satisfactory central nervous system (CNS) penetration. Furthermore, 7f.HCl reduced the infarct volume in vivo in a rat middle cerebral artery (MCA) occlusion model when administrated intraperitoneally.
Subject(s)
Protein Kinase Inhibitors/therapeutic use , Pyrimidines/chemistry , Stroke/drug therapy , src-Family Kinases/antagonists & inhibitors , Animals , Crystallography, X-Ray , Magnetic Resonance Spectroscopy , Male , Models, Molecular , Protein Kinase Inhibitors/chemistry , Pyrimidines/pharmacology , Rats , Rats, Sprague-Dawley , Spectrophotometry, InfraredABSTRACT
We synthesized and evaluated a series of C-5 substituted imidazo[1,5-a]pyrazine derivatives to identify potent c-Src inhibitors as potential therapeutic agents for acute ischemic stroke. Among these compounds, compound 14c.HCl demonstrated remarkable central nervous system (CNS) penetration and significant neuroprotective efficacy in vivo in rat models.
Subject(s)
Brain Ischemia/complications , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Imidazoles/chemical synthesis , Imidazoles/pharmacology , Neuroprotective Agents/chemical synthesis , Neuroprotective Agents/pharmacology , Pyrazines/chemical synthesis , Pyrazines/pharmacology , Stroke/drug therapy , Stroke/etiology , src-Family Kinases/antagonists & inhibitors , Acute Disease , Animals , Crystallography, X-Ray , Enzyme Inhibitors/blood , Enzyme-Linked Immunosorbent Assay , Humans , Indicators and Reagents , Magnetic Resonance Spectroscopy , Mass Spectrometry , Models, Molecular , Molecular Conformation , Neuroprotective Agents/blood , Rats , Spectrophotometry, Infrared , Structure-Activity RelationshipABSTRACT
This report proposes a beta(3)-adrenoceptor (AR) selective agonist, 2-[2-chloro-4-(2-([(1S,2R)-2-hydroxy-2-(4-hydroxyphenyl)-1-methylethyl]amino)ethyl)phenoxy]acetic acid (1a), as a novel agent for treating urinary bladder dysfunction. This compound and its relatives have a unique feature among beta(3)-AR agonists: two chiral carbons are adjacently structured on the left side of the molecule. To study the relationship between the stereoconfiguration of the vicinal chiral carbons in 1a and beta-AR agonistic activity, the four stereoisomers were synthesized via oxazolidinone prepared by intracyclization involving inversion of the beta-hydroxy group. The in vitro assays using rat atria for beta(1)-AR, rat uteri for beta(2)-AR, and ferret detrusor for beta(3)-AR showed that 1a possessed potent beta(3)-AR agonistic activity (EC(50) = 3.85 nM) and 3700- and 1700-fold selectivity for beta(3)-AR relative to beta(1)- and beta(2)-AR, respectively. Comparison of the four isomers revealed that the (alphaS,betaR)-compound (1a) was not only the most potent agonist but was also the most selective for beta(3)-AR. In the anesthetized rat, intravenous administration of 1a brought about a sufficient decrement of the intrabladder pressure (ED(50) = 12 microg/kg), and intraduodenal administration of 2a, which is the ethyl ester of 1a, led to same result (ED(50) = 0.65 mg/kg). Moreover, no effects on the cardiovascular system were observed in either test.