Substituted benzothiadizine inhibitors of Hepatitis C virus polymerase.

The synthesis and optimisation of HCV NS5B polymerase inhibitors with improved potency versus the existing compound 1 is described. Substitution in the benzothiadiazine portion of the molecule, furnishing improvement in potency in the high protein Replicon assay, is highlighted, culminating in the discovery of 12h, a highly potent oxyacetamide derivative.

Synthesis and biological activity of heteroaryl 3-(1,1-dioxo-2H-(1,2,4)-benzothiadizin-3-yl)-4-hydroxy-2(1H)-quinolinone derivatives as hepatitis C virus NS5B polymerase inhibitors.

Modification of the benzo rings of 3-(1,1-dioxo-2H-(1,2,4)-benzothiadiazin-3-yl)-4-hydroxy-2(1H)-quinolinones into heteroaromatic systems was investigated to enhance physicochemical properties and potency profile of this class of inhibitors. The synthesis and biological activity of the derived compounds is discussed.

Antagonists of the calcium receptor I. Amino alcohol-based parathyroid hormone secretagogues.

Functional screening of the former SmithKline Beecham compound collection against the human calcium receptor (CaR) resulted in the identification of the amino alcohol-based hit 2 (IC(50) = 11 microM). Structure-activity studies of 2 focused on the optimization of the right- and left-hand side aromatic moieties as well as the amino alcohol linker region. Critical to the optimization of this antagonist template was the discovery that the chirality of the C-2 secondary alcohol played a key role in enhancing both CaR potency as well as selectivity over the beta-adrenergic receptor subtypes.

Identification of 4-(2-(4-amino-1,2,5-oxadiazol-3-yl)-1-ethyl-7-{[(3S)-3-piperidinylmethyl]oxy}-1H-imidazo[4,5-c]pyridin-4-yl)-2-methyl-3-butyn-2-ol (GSK690693), a novel inhibitor of AKT kinase.

Overexpression of AKT has an antiapoptotic effect in many cell types, and expression of dominant negative AKT blocks the ability of a variety of growth factors to promote survival. Therefore, inhibitors of AKT kinase activity might be useful as monotherapy for the treatment of tumors with activated AKT. Herein, we describe our lead optimization studies culminating in the discovery of compound 3g (GSK690693).

Urotensin-II receptor antagonists: synthesis and SAR of N-cyclic azaalkyl benzamides.

SAR exploration of the central diamine, benzyl, and terminal aminoalkoxy regions of the N-cyclic azaalkyl benzamide series led to the identification of very potent human urotensin-II receptor antagonists such as 1a with a K(i) of 4 nM. The synthesis and structure-activity relationships (SAR) of N-cyclic azaalkyl benzamides are described.

3-(1,1-dioxo-2H-(1,2,4)-benzothiadiazin-3-yl)-4-hydroxy-2(1H)-quinolinones, potent inhibitors of hepatitis C virus RNA-dependent RNA polymerase.

Recently, we disclosed a new class of HCV polymerase inhibitors discovered through high-throughput screening (HTS) of the GlaxoSmithKline proprietary compound collection. This interesting class of 3-(1,1-dioxo-2H-1,2,4-benzothiadiazin-3-yl)-4-hydroxy-2(1H)-quinolinones potently inhibits HCV polymerase enzymatic activity and inhibits the ability of the subgenomic HCV replicon to replicate in Huh-7 cells. This report will focus on the structure-activity relationships (SAR) of substituents on the quinolinone ring, culminating in the discovery of 1-(2-cyclopropylethyl)-3-(1,1-dioxo-2H-1,2,4-benzothiadiazin-3-yl)-6-fluoro-4-hydroxy-2(1H)-quinolinone (130), an inhibitor with excellent potency in biochemical and cellular assays possessing attractive molecular properties for advancement as a clinical candidate.

New benzimidazoles as thrombopoietin receptor agonists.

A novel benzimidazole series of small-molecule thrombopoietin receptor agonists has been discovered. Herein, we discuss the preliminary exploration of structure-activity relationships within this chemotype.

Aminoalkoxybenzyl pyrrolidines as novel human urotensin-II receptor antagonists.

High throughput screening of the corporate compound collection led to the discovery of a novel series of substituted aminoalkoxybenzyl pyrrolidines as human urotensin-II receptor antagonists. The synthesis, initial structure-activity relationships, and optimization of the initial hit that led to the identification of a truncated sub-series, represented by SB-436811 (1a), are described.

Nonpeptidic urotensin-II receptor antagonists I: in vitro pharmacological characterization of SB-706375.

1. SB-706375 potently inhibited [(125)I]hU-II binding to both mammalian recombinant and 'native' UT receptors (K(i) 4.7+/-1.

Identification of small molecule inhibitors of the hepatitis C virus RNA-dependent RNA polymerase from a pyrrolidine combinatorial mixture.

HTS of the compound collection for inhibition of the HCV RNA dependent RNA polymerase identified two 168 member N-acyl pyrrolidine combinatorial mixture hits. Deconvolution and expansion of these mixtures by solid phase synthesis to establish initial SAR and identify a potent inhibitor is reported.

Selective binding and oligomerization of the murine granulocyte colony-stimulating factor receptor by a low molecular weight, nonpeptidyl ligand.

Granulocyte colony-stimulating factor regulates neutrophil production by binding to a specific receptor, the granulocyte colony-stimulating factor receptor, expressed on cells of the granulocytic lineage. Recombinant forms of granulocyte colony-stimulating factor are used clinically to treat neutropenias. As part of an effort to develop granulocyte colony-stimulating factor mimics with the potential for oral bioavailability, we previously identified a nonpeptidyl small molecule (SB-247464) that selectively activates murine granulocyte colony-stimulating factor signal transduction pathways and promotes neutrophil formation in vivo.

Identification and biological characterization of heterocyclic inhibitors of the hepatitis C virus RNA-dependent RNA polymerase.

The hepatitis C virus (HCV) NS5B protein encodes an RNA-dependent RNA polymerase (RdRp), the primary catalytic enzyme of the HCV replicase complex. We established a biochemical RNA synthesis assay, using purified recombinant NS5B lacking the C-terminal 21 amino acid residues, to identify potential polymerase inhibitors from a high throughput screen of the GlaxoSmithKline proprietary compound collection. The benzo-1,2,4-thiadiazine compound 1 was found to be a potent, highly specific inhibitor of NS5B.

Identification of a pharmacophore for thrombopoietic activity of small, non-peptidyl molecules. 2. Rational design of naphtho[1,2-d]imidazole thrombopoietin mimics.

The invention of a new class of naphtho[1,2-d]imidazole thrombopoietin mimics based on a pharmacophore hypothesis for small-molecule thrombopoietic agonists is discussed. Parallel array synthesis and purification techniques allowed for the rapid exploration of structure-activity relationships within this class and for the improvement in TPO mimetic potencies and efficacies.

Identification of a pharmacophore for thrombopoietic activity of small, non-peptidyl molecules. 1. Discovery and optimization of salicylaldehyde thiosemicarbazone thrombopoietin mimics.

High-throughput screening has resulted in the discovery of thiosemicarbazone thrombopoietin mimics. A shared pharmacophore hypothesis between this series and a previously identified class, the pyrazol-4-ylidenehydrazines, led to the rapid optimization of both potency and efficacy of the thiosemicarbazones. The application of high-throughput chemistry and purification techniques allowed for the rapid elucidation of structure-activity relationships.