The discovery and optimisation of benzazepine sulfonamide and sulfones as potent agonists of the motilin receptor

Optimisation of a series of benzazepine sulfonamide hit compounds identified from high throughput screening led to the discovery of a new series of tractable, potent motilin receptor agonists.     

Discovery of the first non-ATP competitive IGF-1R kinase inhibitors: advantages in comparison with competitive inhibitors

A new series of IGF-1R inhibitors related to hydantoins were identified from a lead originating from HTS. Their noncompetitive property as well as their slow binding characteristics provided a series of compounds with unique selectivity and excellent cellular activities.     

Discovery of a series of potent and selective human H4 antagonists using ligand efficiency and libraries to explore structure-activity relationship (SAR)

We describe the identification of a potent, selective lead series that shows antagonism against the human histamine H4 receptor from thirteen actives identified in an HTS as part of a hit to lead program. By focusing on ligand efficiency and concurrently using a diversity based approach, compounds based around 2,4-diaminopyrimidine were identified with compound 25 being quickly shown to be a good lead. It also had the highest ligand efficiency in the series.     

N-isoquinolin-5-yl-N'-aralkyl-urea and -amide antagonists of human vanilloid receptor 1

Starting from a low micromolar agonist lead identified by high-throughput screening, series of N-isoquinolin-5-yl-N'-aralkyl ureas and analogous amides were developed as potent antagonists of human vanilloid receptor 1 (VR1). The synthesis and structure-activity relationships (SAR) of the series are described.     

Mitochondrial complex I from Arabidopsis and rice: orthologs of mammalian and fungal components coupled with plant-specific subunits

The NADH:ubiquinone oxidoreductase of the mitochondrial respiratory chain is a large multisubunit complex in eukaryotes containing 30-40 different subunits. Analysis of this complex using blue-native gel electrophoresis coupled to tandem mass spectrometry (MS) has identified a series of 30 different proteins from the model dicot plant, Arabidopsis, and 24 different proteins from the model monocot plant, rice. These proteins have been linked back to genes from plant genome sequencing and comparison of this dataset made with predicted orthologs of complex I components in these plants. This analysis reveals that plants contain the series of 14 highly conserved complex I subunits found in other eukaryotic and related prokaryotic enzymes and a small set of 9 proteins widely found in eukaryotic complexes. A significant number of the proteins present in bovine complex I but absent from fungal complex I are also absent from plant complex I and are not encoded in plant genomes. A series of plant-specific nuclear-encoded complex I associated subunits were identified, including a series of ferripyochelin-binding protein-like subunits and a range of small proteins of unknown function. This represents a post-genomic and large-scale analysis of complex I composition in higher plants.     

The design of 8,8-dimethyl[1,6]naphthyridines as potential anticonvulsant agents

Starting from a series of 7-linked tetrahydroisoquinoline derivatives, as exemplified by SB-270664, a new series of 8,8-dimethylnaphthyridine compounds has been identified. SAR studies around these attractive leads have provided compounds such as 12 which display excellent anticonvulsant activity and an encouraging pharmacokinetic profile in vivo.     

Discovery and biological evaluation of benzo[a]carbazole-based small molecule agonists of the thrombopoietin (Tpo) receptor

A novel series of benzo[a]carbazole-based small molecule agonists of the thrombopoietin (Tpo) receptor is reported. Starting from a 3.4 microM high throughput screen hit, members of this series have been identified which are full agonists with functional potency <50 nM and oral bioavailability in mice.     

Mitochondrial complex I from Arabidopsis and rice: orthologs of mammalian and fungal components coupled with plant-specific subunits

The NADH:ubiquinone oxidoreductase of the mitochondrial respiratory chain is a large multisubunit complex in eukaryotes containing 30-40 different subunits. Analysis of this complex using blue-native gel electrophoresis coupled to tandem mass spectrometry (MS) has identified a series of 30 different proteins from the model dicot plant, Arabidopsis, and 24 different proteins from the model monocot plant, rice. These proteins have been linked back to genes from plant genome sequencing and comparison of this dataset made with predicted orthologs of complex I components in these plants. This analysis reveals that plants contain the series of 14 highly conserved complex I subunits found in other eukaryotic and related prokaryotic enzymes and a small set of 9 proteins widely found in eukaryotic complexes. A significant number of the proteins present in bovine complex I but absent from fungal complex I are also absent from plant complex I and are not encoded in plant genomes. A series of plant-specific nuclear-encoded complex I associated subunits were identified, including a series of ferripyochelin-binding protein-like subunits and a range of small proteins of unknown function. This represents a post-genomic and large-scale analysis of complex I composition in higher plants.     

Thiazoles and thiopyridines: novel series of high affinity h5HT(7) ligands

A series of thiazole based 5HT(7) ligands has been identified from screening. Optimisation of the pendent aryl group and modification of the core gave a related series of high affinity, selective thiopyridine based 5HT(7) ligands, the most active of which behaves as a partial agonist.     

Identification and optimisation of 5-amino-7-aryldihydro-1,4-diazepines as 5-HT2A ligands

A several series of low molecular weight 5-HT(2A) leads were identified from an analysis of HTS data, the exploration of SAR and optimization of one series using parallel synthesis are described, affording compound 22 (5-HT(2A) IC(50) 1.1 nM).     

Identification of an aminothiazole series of RORβ modulators

Crystallography has identified stearic acid, ALRT 1550 and ATRA as ligands that bind RORβ, however, none of these molecules represent good starting points to develop optimized small molecule modulators. Recently, Compound 1 was identified as a potent dual RORβ and RORγ inverse agonist with no activity towards RORα (Fig. 1). To our knowledge, this is one of only two small molecule RORβ inverse agonists identified in the primary literature from a tractable chemical series and represents an ideal starting point from which to design RORβ-selective modulators. Herein we describe our SAR optimization efforts that led to a series of potent neutral antagonists of RORβ.     

Discovery of a potent and selective series of pyrazole bacterial methionyl-tRNA synthetase inhibitors

Starting with a micromolar lead identified from high-throughput screening, a series of pyrazoles were discovered with significantly improved potency on bacterial methionyl-tRNA synthetase and selectivity over human methionyl-tRNA synthetase.     

Identification of amide bioisosteres of triazole Oxytocin antagonists

A series of amides were investigated as potential bioisosteres of previously reported triazole Oxytocin antagonists. A range of potent analogues were identified, although SAR for potency and selectivity over the related V_1A and V₂ receptors was found to be somewhat divergent from that observed for the corresponding triazole series. The high synthetic accessibility of this new amide series also facilitated the identification of a range of alternative left hand side (biaryl replacement) substituents which gave good levels of Oxytocin antagonism.     

Tetrahydroquinoline glucocorticoid receptor agonists: discovery of a 3-hydroxyl for improving receptor selectivity

We have previously disclosed a series of glucocorticoid receptor (GR) ligands derived from 6-indole-1,2,3,4-tetrahydroquinolines through structure-activity relationship (SAR) of the pendent C6-indole ring. In parallel with this effort, we now report SAR of the tetrahydroquinoline A-ring that identified the importance of a C3 hydroxyl in improving GR selectivity within a series of non-steroidal GR agonists.     

Tetrahydro-4-quinolinamines identified as novel P2Y(1) receptor antagonists

High-throughput screening of the GSK compound collection against the P2Y(1) receptor identified a novel series of tetrahydro-4-quinolinamine antagonists. Optimal substitution around the piperidine group was pivotal for ensuring activity. An exemplar analog from this series was shown to inhibit platelet aggregation.     

Studies on the synthesis of ether-, substituted alkyl-, or aryl-linked C-disaccharide derivatives

A series of ether-, substituted alkyl-, or aryl-linked disaccharide derivatives have been synthesized in relatively good yield and characterized using different spectral techniques including single-crystal X-ray diffraction (XRD). β-Anomeric forms of sugar moiety in these derivatives were identified from ¹H NMR studies. The existence of inter- and intramolecular hydrogen bonding interactions were identified from single-crystal XRD studies.     

Potent, selective pyrimidinetrione-based inhibitors of MMP-13

Using SAR from two related series of pyrimidinetrione-based inhibitors, compounds with potent MMP-13 inhibition and >100-fold selectivity against other MMPs have been identified. Despite high molecular weights, clogPs, and polar surface areas, the compounds are generally well absorbed and have excellent pharmacokinetic (PK) properties when dosed as sodium salts. In a rat fibrosis model, a compound from the series displayed no fibrosis at exposures many fold greater than its MMP-13 IC50.     

Identification of potent, noncovalent fatty acid amide hydrolase (FAAH) inhibitors

Starting from a series of ureas that were determined to be mechanism-based inhibitors of FAAH, several spirocyclic ureas and lactams were designed and synthesized. These efforts identified a series of novel, noncovalent FAAH inhibitors with in vitro potency comparable to known covalent FAAH inhibitors. The mechanism of action for these compounds was determined through a combination of SAR and co-crystallography with rat FAAH.     

3-Amido-4-anilinoquinolines as CSF-1R kinase inhibitors 2: Optimization of the PK profile

The optimization of compounds from the 3-amido-4-anilinoquinolines series of CSF-1R kinase inhibitors is described. The series has excellent activity and kinase selectivity. Excellent physical properties and rodent PK profiles were achieved through the introduction of cyclic amines at the quinoline 6-position. Compounds with good activity in a mouse PD model measuring inhibition of pCSF-1R were identified.