Biomedical subjects

Ermengilda McCauley

Publications and source records attributed to Ermengilda McCauley.

9 recordsLinked to original sources

PubMed2006

Highly constrained bicyclic VLA-4 antagonists.

VLA-4 is implicated in several inflammatory and autoimmune disease states. A series of cyclic beta-amino acids (beta-aa) was studied as VLA-4 antagonists. Binding affinity was highly dependent on the dihedral angle (phi) between the amino and the carboxyl termini of the beta-aa. Compound 5 m where the beta-aa is embedded in a bicycle possesses the most preferred phi (120 degrees). It is a potent and bioavailable VLA-4 antagonist (VCAM-Ig alpha4beta1 IC50 = 54 nM, rat po F = 49%).

Biological Availability↗

PubMed2003

A small molecule alpha4beta1/alpha4beta7 antagonist differentiates between the low-affinity states of alpha4beta1 and alpha4beta7: characterization of divalent cation dependence.

An alpha4beta1/alpha4beta7 dual antagonist, 35S-compound 1, was used as a model ligand to study the effect of divalent cations on the activation state and ligand binding properties of alpha4 integrins. In the presence of 1 mM each Ca2+/Mg2+, 35S-compound 1 bound to several cell lines expressing both alpha4beta1 and alpha4beta7, but 2S-[(1-benzenesulfonyl-pyrrolidine-2S-carbonyl)-amino]-4-[4-methyl-2S-(methyl-[2-[4-(3-o-tolyl-ureido)-phenyl]-acetyl]-amino) pentanoylamino]-butyric acid (BIO7662), a specific alpha4beta1 antagonist, completely inhibited 35S-compound 1 binding, suggesting that alpha4beta1 was responsible for the observed binding. 35S-Compound 1 bound RPMI-8866 cells expressing predominantly alpha4beta7 with a KD of 1.9 nM in the presence of 1 mM Mn2+, and binding was inhibited only 29% by BIO7662, suggesting that the probe is a potent antagonist of activated alpha4beta7. With Ca2+/Mg2+, 35S-compound 1 bound Jurkat cells expressing primarily alpha4beta1 with a KD of 18 nM. In contrast, the binding of 35S-compound 1 to Mn2+-activated Jurkat cells occurred slowly, reaching equilibrium by 60 min, and failed to dissociate within another 60 min. The ability of four alpha4beta1/alpha4beta7 antagonists to block binding of activated alpha4beta1 or alpha4beta7 to vascular cell adhesion molecule-1 or mucosal addressin cell adhesion molecule-1, respectively, or to 35S-compound 1 was measured, and a similar rank order of potency was observed for native ligand and probe. Inhibition of 35S-compound 1 binding to alpha4beta1 in Ca2+/Mg2+ was used to identify nonselective antagonists among these four. These studies demonstrate that alpha4beta1 and alpha4beta7 have distinct binding properties for the same ligand, and binding parameters are dependent on the state of integrin activation in response to different divalent cations.

Binding Sites↗

PubMed2003

N-(3-phenylsulfonyl-3-piperidinoyl)-phenylalanine derivatives as potent, selective VLA-4 antagonists.

The SAR of 1-sulfonyl-cyclopentyl carboxylic acid amides, ligands for the VLA-4 integrin, was investigated. This effort resulted in the identification of N-(3-phenylsulfonyl-3-piperidinoyl)-(L)-4-(2',6'-dimethoxyphenyl)phenylalanine 52 as a potent, selective VLA-4 antagonist (IC(50)=90 pM). Expansion of the SAR demonstrated that this structural unit can be used to identify a diverse series of sub-nanomolar antagonists.

Amides↗

PubMed2002

Substituted 3-amino biaryl propionic acids as potent VLA-4 antagonists.

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.

Administration, Oral↗

PubMed2002

N-Tetrahydrofuroyl-(L)-phenylalanine derivatives as potent VLA-4 antagonists.

Given the proposed involvement of VLA-4 in inflammatory processes, a program to identify orally active VLA-4 antagonists was initiated. Herein, we report the discovery of a N-tetrahydrofuroyl-(L)-phenylalanine derivative (17) and related analogues as potent VLA-4 antagonists with good oral bioavailability.

Administration, Oral↗

PubMed2002

Substituted N-(3,5-dichlorobenzenesulfonyl)-L-prolyl-phenylalanine analogues as potent VLA-4 antagonists.

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.

Animals↗

PubMed2002

Identification of unique VLA-4 antagonists from a combinatorial library.

A combinatorial library of 28 pools of 180 compounds (345 diastereomers) was designed and prepared in support of the delineation of the SAR of two prototypical VLA-4 antagonists. Deconvolution of the active pools led to the identification of three novel series of VLA-4 antagonists with low nanomolar potencies.

Anti-Inflammatory Agents↗

PubMed2002

The discovery of small molecule carbamates as potent dual alpha(4)beta(1)/alpha(4)beta(7) integrin antagonists.

The alpha(4)beta(1) and alpha(4)beta(7) integrins are implicated in several inflammatory disease states. Systematic SAR studies of an alpha(4)beta(1)-specific arylsulfonyl-Pro-Tyr lead led to the identification of a new alpha(4)beta(7) binding site, best captured by O-carbamates of Tyr for this structural class. Several compounds showed a 200- to 400-fold improvement in alpha(4)beta(7) binding affinity while maintaining subnanomolar alpha(4)beta(1) activity, for example 2l, VCAM-Ig alpha(4)beta(1) IC(50)=0.13 nM, VCAM-Ig alpha(4)beta(7) IC(50)=1.92 nM.

Carbamates↗

PubMed2002

Alpha(4)beta(7)/alpha(4)beta(1) dual integrin antagonists block alpha(4)beta(7)-dependent adhesion under shear flow.

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.

Animals↗