ABSTRACT
The design, synthesis, and binding activity of ring constrained analogs of the acyclic cannabinoid-1 receptor (CB1R) inverse agonist taranabant 1 are described. The initial inspiration for these taranabant derivatives was its conformation 1a, determined by (1)H NMR, X-ray, and molecular modeling. The constrained analogs were all much less potent than their acyclic parent structure. The results obtained are discussed in the context of a predicted binding of 1 to a homology model of CB1R.
Subject(s)
Amides/chemistry , Anti-Obesity Agents/chemical synthesis , Pyridines/chemistry , Receptor, Cannabinoid, CB1/chemistry , Amides/chemical synthesis , Amides/pharmacology , Anti-Obesity Agents/chemistry , Anti-Obesity Agents/pharmacology , Computer Simulation , Humans , Models, Molecular , Molecular Conformation , Protein Binding , Pyridines/chemical synthesis , Pyridines/pharmacology , Receptor, Cannabinoid, CB1/metabolismABSTRACT
A series of substituted N-(3,5-dichlorobenzenesulfonyl)-(L)-prolyl- and (L)-azetidyl-beta-biaryl beta-alanine derivatives was prepared as selective and potent VLA-4 antagonists. The 2,6-dioxygenated biaryl substitution pattern is important for optimizing potency. Oral bioavailability was variable and may be a result of binding to circulating plasma proteins.
Subject(s)
Integrin alpha4beta1/antagonists & inhibitors , Propionates/chemical synthesis , Administration, Oral , Alanine/chemical synthesis , Alanine/pharmacokinetics , Alanine/pharmacology , Biological Availability , Humans , Inhibitory Concentration 50 , Jurkat Cells , Metabolic Clearance Rate , Propionates/pharmacokinetics , Propionates/pharmacology , Protein Binding , Structure-Activity Relationship , Vascular Cell Adhesion Molecule-1/metabolismABSTRACT
A series of potent N-(aralkyl-, arylcycloalkyl-, and heteroaryl-acyl)-4-biphenylalanine VLA-4 antagonists was prepared by rapid analogue methods using solid-phase chemistry. Further optimization led to several highly potent compounds (IC(50) <1 nM). Evaluation of rat pharmacokinetic revealed generally high clearance.
Subject(s)
Integrin alpha4beta1/antagonists & inhibitors , Phenylalanine/chemical synthesis , Phenylalanine/pharmacology , Animals , Binding Sites , Inhibitory Concentration 50 , Molecular Structure , Phenylalanine/analogs & derivatives , Phenylalanine/pharmacokinetics , Rats , Structure-Activity RelationshipABSTRACT
The alpha(4) integrin, alpha(4)beta(7), plays an important role in recruiting circulating lymphocytes to the gastrointestinal tract, where its ligand mucosal addressin cell adhesion molecule-1 (MAdCAM-1) is preferentially expressed on high endothelial venules (HEVs). Dual antagonists of alpha(4)beta(1) and alpha(4)beta(7), N-(2,6-dichlorobenzoyl)-(L)-4-(2',6'-bis-methoxyphenyl)phenylalanine (TR14035) and N-(N-[(3,5-dichlorobenzene)sulfonyl]-2-(R)-methylpropyl)-(D)-phenylalanine (compound 1), were tested for their ability to block the binding of alpha(4)beta(7)-expressing cells to soluble ligand in suspension and under in vitro and in vivo shear flow. Compound 1 and TR14035 blocked the binding of human alpha(4)beta(7) to an (125)I-MAdCAM-Ig fusion protein with IC(50) values of 2.93 and 0.75 nM, respectively. Both compounds inhibited binding of soluble ligands to alpha(4)beta(1) or alpha(4)beta(7) on cells of human or rodent origin with similar potency. Under shear flow in vitro, TR14035 and compound 1 blocked binding of human alpha(4)beta(7)-expressing RPMI-8866 cells or murine mesenteric lymph node lymphocytes to MAdCAM-Ig with IC(50) values of 0.1 and 1 microM, respectively. Intravital microscopy was used to quantitate alpha(4)-dependent adhesion of fluorescent murine lymphocytes in Peyer's patch HEVs. When cells were prestimulated with 2 mM Mn(2+) to activate alpha(4)beta(7) binding to ligand, anti-alpha(4) monoclonal antibody (mAb) [10 mg/kg (mpk) i.v.] blocked adhesion by 95%, and anti-beta(1) mAb did not block adhesion, demonstrating that this interaction was dependent on alpha(4)beta(7). TR14035 blocked adhesion to HEVs [ED(50) of 0.01-0.1 mpk i.v.], and compound 1 blocked adhesion by 47% at 10 mpk i.v. Thus, alpha(4)beta(7)/alpha(4)beta(1) antagonists blocked alpha(4)beta(7)-dependent adhesion of lymphocytes to HEVs under both in vitro and in vivo shear flow.
Subject(s)
Integrins/antagonists & inhibitors , Phenylalanine/pharmacology , Receptors, Lymphocyte Homing/antagonists & inhibitors , Animals , Antibodies, Blocking/pharmacology , Antibodies, Monoclonal/pharmacology , Antineoplastic Combined Chemotherapy Protocols/immunology , Cell Adhesion/drug effects , Cell Adhesion Molecules , Cyclophosphamide/immunology , Doxorubicin/immunology , Endothelium, Vascular/cytology , Endothelium, Vascular/drug effects , Etoposide/immunology , Female , Flow Cytometry , Humans , Immunoglobulin G/isolation & purification , Immunoglobulin G/pharmacology , Immunoglobulins , Integrin alpha4beta1 , Ligands , Lymphocytes/drug effects , Methotrexate/immunology , Mice , Mice, Inbred BALB C , Mucoproteins/antagonists & inhibitors , Peyer's Patches/cytology , Peyer's Patches/drug effects , Phenylalanine/analogs & derivatives , Recombinant Fusion Proteins/pharmacology , RheologyABSTRACT
Acylated beta-amino acids are described as potent, specific and orally bioavailable antagonists of VLA-4. The initial lead was identified from a combinatorial library. Subsequent optimization using a traditional medicinal chemistry approach led to significant improvement in potency (up to 8-fold) while maintaining good pharmacokinetic properties.
Subject(s)
Amino Acids/chemical synthesis , Inflammation Mediators/chemical synthesis , Integrin alpha4beta1/antagonists & inhibitors , Acylation , Administration, Oral , Amino Acids/metabolism , Amino Acids/pharmacokinetics , Animals , Biological Availability , Combinatorial Chemistry Techniques , Drug Evaluation, Preclinical , Inflammation Mediators/metabolism , Inflammation Mediators/pharmacokinetics , Metabolic Clearance Rate , Protein Binding , Rats , Rats, Sprague-Dawley , Stereoisomerism , Structure-Activity RelationshipABSTRACT
A series of substituted N-(3,5-dichlorobenzenesulfonyl)-L-prolyl- and alpha-methyl-L-prolyl-phenylalanine derivatives was prepared as VLA-4/VCAM antagonists. The compounds showed excellent potency with a wide variety of neutral, polar, electron withdrawing or donating groups on the phenylalanine ring (IC50 approximately 1 nM). Heteroaryl ring substitution for phenylalanine was also well tolerated. Pharmacokinetic studies in rat were performed on a representative set of compounds in both series.
