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Poor solubility and cationic amphiphilic drug-likeness were liabilities identified for a lead series of S1P3-sparing, S1P1 agonists originally developed from a high-throughput screening campaign. This work describes the subsequent optimization of these leads by balancing potency, selectivity, solubility and overall molecular charge. Focused SAR studies revealed favorable structural modifications that, when combined, produced compounds with overall balanced profiles. The low brain exposure observed in rat suggests that these compounds would be best suited for the potential treatment of peripheral autoimmune disorders.

An extension of our previously reported series of macrocyclic ortho-aminobenzamide Hsp90 inhibitors is reported. Addition of a second methyl group to the tether provided analogs that show increased potency in binding as well as cell-proliferation assays and, more importantly, are stable toward microsomes. We wish to disclose the discovery of a macrocycle which showed impressive biomarker activity 24-h post dosing and which demonstrated prolonged exposure in tumors. When studied in a lung cancer xenograft model, the compound demonstrated significant tumor size reduction.

A novel series of macrocyclic ortho-aminobenzamide Hsp90 inhibitors is reported. In continuation of our research, heterocycle-containing tethers were explored with the intent to further improve potency and minimize hERG liabilities. This effort culminated in the discovery of compound 10, which efficiently suppressed proliferation of HCT116 and U87 cells. This compound showed prolonged Hsp90-inhibitory activity at least 24h post-administration consistent with elevated and prolonged exposure in the tumor. When studied in a xenograft model, the compound demonstrated significant suppression of tumor growth.

A novel series of macrocyclic ortho-aminobenzamide Hsp90 inhibitors is reported. In continuation of our research in this area, macrocyclic amides and lactams were explored to reduce the risk of hERG liabilities. This effort culminated in the discovery of compound 38, which showed a favorable in vitro profile, and efficiently suppressed proliferation of several relevant cell lines. This compound showed prolonged Hsp90-inhibitory activity at least 24 h post-administration, consistent with elevated and prolonged exposure in the tumor.

A novel series of macrocyclic ortho-aminobenzamide Hsp90 inhibitors is reported. A basic nitrogen within the tether linking the aniline nitrogen atom to a tetrahydroindolone moiety allowed access to compounds with good physical properties. Important structure-activity relationship information was obtained from this series which led to the discovery of a soluble and stable compound which is potent in an Hsp90 binding and cell-proliferation assay.

Novel indazolylpyrazolo[1,5-a]pyrimidine analogues have been prepared and found to be extremely potent type I B-Raf inhibitors. The lead compound shows good selectivity against a panel of 60 kinases, possesses a desirable pharmacokinetic profile, and demonstrates excellent in vivo antitumor efficacy in B-Raf mutant xenograft models.

A series of pyrazolo[1,5-alpha]pyrimidine analogs has been prepared and found to be potent and selective B-Raf inhibitors. Molecular modeling suggests they bind to the active conformation of the enzyme.

A novel series of pyrazolo[1,5-a]pyrimidines bearing a 3-hydroxyphenyl group at C(3) and substituted tropanes at C(7) have been identified as potent B-Raf inhibitors. Exploration of alternative functional groups as a replacement for the C(3) phenol demonstrated indazole to be an effective isostere. Several compounds possessing substituted indazole residues, such as 4e, 4p, and 4r, potently inhibited cell proliferation at submicromolar concentrations in the A375 and WM266 cell lines, and the latter two compounds also exhibited good therapeutic indices in cells.

A series of alpha-sulfone piperidine hydroxamate TACE inhibitors 11a-n bearing a quinolinyl methyl P1' group was prepared, and their activity was compared to analogous alpha- and beta-sulfone piperidine hydroxamates with a butynyloxy P1' group. The quinolinyl methyl P1' group affords increased inhibitory enzyme activity relative to the corresponding butynyloxy P1' analogs in the alpha-sulfone piperidine hydroxamate series, and greater selectivity than the corresponding butynyloxy P1' analogs in the beta-sulfone piperidine hydroxamate series.

The naturally occurring pyranonaphthoquinone (PNQ) antibiotic lactoquinomycin and related aglycones were found to be selective inhibitors of the serine-threonine kinase AKT. A set of synthetic PNQs were prepared and a minimum active feature set and preliminary SAR were determined. PNQ lactones inhibit the proliferation of human tumor cell lines containing constitutively activated AKT and show expected effects on cellular biomarkers. Biochemical data are presented supporting a proposed bioreductive alkylation mechanism of action.

By focusing on the P1 portion of the piperidine β-sulfone ligands we identified a motif that induces selectivity and resulted in a series of TACE inhibitors that demonstrated excellent in vitro potency against isolated TACE enzyme and excellent selectivity over MMPs 1, 2, 9, 13, and 14.

A series of butynyloxyphenyl beta-sulfone piperidine hydroxamate TACE inhibitors was designed and synthesized. The resulting structure-activity relationship and MMP selectivity of the series were examined. Of the compounds investigated, 17s has excellent in vitro potency against isolated TACE enzyme, shows good selectivity over MMP-1, -2, -7, -8, -9, -13, and -14, and oral activity in an in vivo mouse model of TNF-alpha production.

A series of thiomorpholine sulfonamide hydroxamate TACE inhibitors, all bearing propargylic ether P1′ groups, was explored. In particular, compound 5h has excellent in vitro potency against isolated TACE enzyme and in cells, oral activity in a model of TNF-α production and a collagen-induced arthritis model, was selected as a clinical candidate for the treatment of RA.

Modification of alpha-biphenylsulfonamidocarboxylic acids led to potent and selective MMP-13 inhibitors. Compound 16 showed 100% oral bioavailability in rats and demonstrated50% inhibition of bovine cartilage degradation at 10 ng/mL.

The structure-based design and synthesis of a series of novel biphenyl sulfonamide carboxylic acids as potent MMP-13 inhibitors with selectivity over MMP-1, MMP-2, MMP-3, MMP-7, MMP-8, MMP-9, MMP-14, Aggrecanase 1, and TACE are described.

Potent and selective TACE and MMP inhibitors utilizing the diazepine and thiazepine ring systems were synthesized and evaluated for biological activity in in vitro and in vivo models of TNF-α release. Oral activity in the mouse LPS model of TNF-α release was seen. Efficacy in the mouse collagen induced arthritis model was achieved with diazepine 20.

TNF-alpha converting enzyme (TACE) is a validated therapeutic target for the development of oral tumor necrosis factor-alpha (TNF-alpha) inhibitors. Here we report the pre-clinical results and characterization of a selective and potent TACE inhibitor, (2R, 3S)-2-([[4-(2-butynyloxy)phenyl]sulfonyl]amino)-N,3-dihydroxybutanamide (TMI-2), in various in vitro and in vivo assays. TMI-2 is a potent TACE inhibitor in an enzymatic FRET assay (IC50=2 nM). It is more than 250-fold selective over MMP-1, -7, -9, -14, and ADAM-10 in vitro. In cell-based assays and human whole blood, TMI-2 inhibits lipopolysaccharide (LPS)-induced TNF secretion with IC50s1 uM. Importantly, TMI-2 inhibits the spontaneous release of TNF-alpha in human synovium tissue explants of rheumatoid arthritis patients with an IC50 of 0.8 microM. In vivo, TMI-2 potently inhibits LPS-induced TNF-alpha production in mice (ED50=3 mg/kg). In the adjuvant-induced arthritis (AIA) model in rats, treatment with TMI-2 at 30 mg/kg and 100 mg/kg p.o. b.i.d. was highly effective in reducing joint arthritis scores. In a semi-therapeutic collagen-induced arthritis (CIA) model in mice, TMI-2 is highly effective in reducing disease severity scores after oral treatment at 100 mg/kg twice per day. In summary, TMI-2 is a potent and selective TACE inhibitor that inhibits TNF-alpha production and reduces the arthritis scores in pre-clinical models. TMI-2 represents a novel class of TACE inhibitors that may be effective and beneficial in the treatment of rheumatoid arthritis as well as other TNF-mediated inflammatory autoimmune diseases.

A series of benzodiazepine MMP/TACE inhibitors bearing polar moieties has been synthesized in an effort to optimize inhibitory activity against LPS-stimulated TNF production in human monocytes and oral activity in a murine LPS model.

4-[3-Chloro-4-(1-methyl-1H-imidazol-2-ylsulfanyl)]anilino-6,7-diethoxy-3-quinolinecarbonitrile (3) was identified as a MEK1 kinase inhibitor with exceptional activity against LoVo cells. The structure-activity relationships of the C-4 aniline substituents were explored, and water-solubilizing groups were added at the C-7 position to improve physical properties. Secondary cellular assays revealed that a compound possessing the appropriate aniline substituents inhibited MEK1 as well as MAPK phosphorylation, thereby acting as a dual inhibitor of the Ras-MAPK signaling cascade.

Aryl fluorides react rapidly with 2-butyn-1-ol and potassium t-butoxide in DMSO under microwave irradiation to give propargylic ethers. These ethers isomerize in situ to the corresponding allenyl ethers, which hydrolyze on work-up to give phenols in good yield.

This book reviews macrocycles in drug discovery, both those of natural origin and semi-synthetic derivatives of natural products, and those designed and synthesized based on principles of medicinal chemistry. The medicinal chemistry of macrocyclic natural products is interesting in itself, but lessons learned from these compounds, in terms of the relationship between structure and desirable physicochemical properties, are now informing the design of fully synthetic macrocyclic drug candidates against a variety of targets including kinases, ATPases, proteases, GPCRs and others. Furthermore, as more non-classical drug targets, such as protein–protein interactions, are pursued in the pharmaceutical industry, macrocyclic molecules are generating increasing interest as they offer a way to provide drug–protein interactions that cover a larger surface area than traditional small molecules. A variety of macrocycles have become important drugs or have been identified as leads to marketed drugs. This text will discuss these compounds, their pharmacology and synthesis, in the context of their broad chemotype as compounds composed of large rings. Providing a wide reaching review of this important area in a single volume, this book will be of interest to biochemists, pharmaceutical scientists and medicinal chemists working in industry or academia.

Heteroaryl and cycloalkyl sulfonamide-hydroxamic acid MMP inhibitors were investigated. Of these, the pyridyl analogue 2 is the most potent and selective inhibitor of MMP-9 and MMP-13 in vitro.

The high-resolution NMR solution structure of the catalytic fragment of human collagenase-3 (MMP-13) was used as a starting point for structure-based design of selective inhibitors for MMP-13. The major structural difference observed between the MMP structures is the relative size and shape of the S1‘ pocket where this pocket is significantly longer for MMP-13, nearly reaching the surface of the protein. On the basis of the extended nature of the MMP-13 S1‘ pocket an inhibitor potent and selective for MMP-13 was designed from an initial high throughput screening (HTS) lead. CL-82198 was identified as a weak (10 μM) inhibitor against MMP-13 while demonstrating no activity against MMP-1, MMP-9, or the related enzyme TACE. The drug-like properties of CL-82198 made it an ideal candidate for optimization of enzyme potency and selectivity. On the basis of NMR binding studies, it was shown that inhibitor CL-82198 bound within the entire S1‘ pocket of MMP-13 which is the basis of its selectivity against MMP-1, MM...

A novel series of matrix metalloproteinase (MMP) inhibitors is described. Incorporation of a terminal α-mercaptoketone or α-mercaptoalcohol in the zinc binding domain of a series of inhibitors led to compounds exhibiting low nanomolar activity against collagenase-1 (MMP-1), stromelysin (MMP-3), and gelatinase-B (MMP-9).

A series of succinyl based mercaptoketones and diastereomeric mercaptoalcohols were prepared and evaluated in vitro as inhibitors of the matrix metalloproteinases collagenase-1 (MMP-1), stromelysin (MMP-3), and gelatinase-B (MMP-9).

Matrix metalloproteinases (MMP) have been implicated in a variety of diseases in which the destruction of connective tissue is an important pathological event. These include osteo and rheumatoid arthritis, tumor metastasis and angiogenesis, and corneal ulceration. As a result, there has been a great deal of activity directed towards the design of MMP inhibitors as therapeutic agents for the treatment of these conditions. Progress in the field has now evolved to a degree where potent, low molecular weight, orally active inhibitors have been discovered and advanced to clinical trials. While a majority of inhibitors are dipeptide derivatives, a non-peptide, orally active inhibitor has recently been reported. Some success has also been achieved in the design of subtype selective MMP inhibitors. The elucidation of X-ray and 0NMR structures of several MMPs, and the ability to create homology models of others has provided an understanding of some of the structural requirements leading to potency and specificity. Herein is a review of recent advances in the biology and chemistry of MMPs and MMP inhibitors, including the association of MMPs with specific disease processes, structure activity relationships of MMP inhibitors and factors affecting enzyme specificity and their correlation with MMP structure.

A practical synthetic route for the preparation of compound 2a , a carbocyclic analog of the Δ5-derivative, 1 , of forskolin has been completed. A quinone Diels-Alder reaction is used for the rapid construction of the tricyclic framework of 2 .

Anti-Inflammatory Drug Discovery provides a comprehensive review of recent medicinal chemistry approaches to a variety of important therapeutic targets and provides a key reference for those interested in the prosecution of modern drug discovery programs directed at anti-inflammatory mechanisms of action. The editors, with extensive experience in this field, have selected key thought-leaders who will bring their experience to the medicinal chemistry literature for each target, ranging from components of the arachadonic acid cascade, to kinases, GPCRs, sphingolipids and others, to summarize its background biology and detail new insights, major advances and issues related to bringing new anti-inflammatory therapies to market. Consisting of five main sections key targets covered will include the AA Cascade: mPGES1, cPLA2, Leukotriene A4 Hydrolase, CRTH2; Kinases: P38/PDE4, MAPKAP Kinase 2 (MK2), Syk Kinase Inhibitors, Jak Kinases, IKK , Bruton's Tyrosine Kinase; GPCRs: CCR1, CCR2 Antagonists, CB2 Agonists; Sphingolipids: S1P1 Receptor Agonists, Sphingosine Lyase and Sphingosine Kinase 1 and a final miscellaneous section that looks at Non-Steroidal Dissociated Glucocorticoid Receptor Agonists. The book will be essential reading for pharmacologists, medicinal chemists and pharmaceutical scientists working in industry and academia.

A series of succinyl based mercaptoketones and diastereomeric mercaptoalcohols were prepared and evaluated in vitro as inhibitors of the matrix metalloproteinases collagenase-1 (MMP-1), stromelysin (MMP-3), and gelatinase-B (MMP-9).

Aryl fluorides react rapidly with 2-butyn-1-ol and potassium t-butoxide in DMSO under microwave irradiation to give propargylic ethers. These ethers isomerize in situ to the corresponding allenyl ethers, which hydrolyze on work-up to give phenols in good yield.

As part of our research effort to discover B-Raf kinase inhibitors, we prepared a series of C-3 substituted N-(3-(pyrazolo[1,5-a]pyrimidin-7-yl)phenyl)-3-(trifluoromethyl)benzamides. X-ray crystallography studies revealed that one of the more potent inhibitors (10n) bound to B-Raf kinase without forming a hinge-binding hydrogen bond. With basic amine residues appended to C-3 aryl residues, cellular activity and solubility were enhanced over previously described compounds of this class.

Potent 3,4-disubstituted benzofuran P1' MMP-13 inhibitors have been prepared. Selectivity over MMP-2 was achieved through a substituent at the C4 position of the benzofuran P1' moiety of the molecule. By replacing a backbone benzene with a pyridine and valine with threonine, compounds (e.g., 44) with greatly reduced plasma protein binding were also obtained.

A novel series of non-hydroxamate tryptophan sulfonamide derivatives containing a butynyloxy P1' moiety was identified as inhibitors of TNF-alpha converting enzyme (TACE). The structure-activity relationship of the series was examined via substitution on the tryptophan indole ring. Of the compounds investigated, 2-(4-(but-2-ynyloxy)phenylsulfonamido)-3-(1-(4-methoxybenzyl)-1H-indol-3-yl)propanoic acid (12p) has the best in vitro potency against isolated TACE enzyme with an IC(50) of 80 nM. Compound 12p also shows good selectivity over MMP-1, -13, -14.

The serine/threonine kinase AKT/PKB plays a critical role in cancer and represents a rational target for therapy. Although efforts in targeting AKT pathway have accelerated in recent years, relatively few small molecule inhibitors of AKT have been reported. The development of selective AKT inhibitors is further challenged by the extensive conservation of the ATP-binding sites of the AGC kinase family. In this report, we have conducted a high-throughput screen for inhibitors of activated AKT1. We have identified lactoquinomycin as a potent inhibitor of AKT kinases (AKT1 IC50, 0.149 ± 0.045 μmol/L). Biochemical studies implicated a novel irreversible interaction of the inhibitor and AKT involving a critical cysteine residue(s). To examine the role of conserved cysteines in the activation loop (T-loop), we studied mutant AKT1 harboring C296A, C310A, and C296A/C310A. Whereas the ATP-pocket inhibitor, staurosporine, indiscriminately targeted the wild-type and all three mutant-enzymes, the inhibition by lactoquinomycin was drastically diminished in the single mutants C296A and C310A, and completely abolished in the double mutant C296A/C310A. These data strongly implicate the binding of lactoquinomycin to the T-loop cysteines as critical for abrogation of catalysis, and define an unprecedented mechanism of AKT inhibition by a small molecule. Lactoquinomycin inhibited cellular AKT substrate phosphorylation induced by growth factor, loss of PTEN, and myristoylated AKT. The inhibition was substantially attenuated by coexpression of C296A/C310A. Moreover, lactoquinomycin reduced cellular mammalian target of rapamycin signaling and cap-dependent mRNA translation initiation. Our results highlight T-loop targeting as a new strategy for the generation of selective AKT inhibitors. [Mol Cancer Ther 2007;6(11):OF1–11]

A series of beta-sulfonyl hydroxamate TACE inhibitors, bearing a butynylamino or a butynyloxy P1' group, was designed and synthesized. Of the compounds investigated, 22 has excellent potency against isolated TACE enzyme, shows good selectivity over MMP-2 and MMP-13, and oral activity in an in vivo mouse model of TNF-alpha production.

Publisher Summary Hepatitis C virus (HCV) is a blood-borne pathogen belonging to the Flaviviridae family of viruses, which also includes the West Nile, Yellow Fever, and Dengue viruses. Most small molecule inhibitor approaches to HCV have been focused on inhibition of essential viral targets, particularly the NS3-4A protease and the NS5B RNA-dependent RNA polymerase although other targets are being pursued. A variety of nucleoside competitive inhibitors of HCV NS5B, the RdRp encoded at the 3´-terminal portion of the HCV genome and required for viral replication, have also been thoroughly studied and advanced to clinical trials. By analogy to AIDS, where HIV protease plays a crucial role in processing mature virions, HCV uses the NS3-4A (aka NS3) protease in a similar manner making it a very attractive inhibition target. The key difference between the two proteases is that the HIV protease active site forms a well-defined active site while the NS3 protease has a shallow cleft with fewer opportunities to bind to small molecules. As a result, NS3 inhibitors have been generally more complex, more peptide-like and larger than those for HIV.

Introduction Tumor necrosis factor-alpha (TNFα) participates in many inflammatory processes. TNFα modulators show beneficial effects for the treatment of many diseases including rheumatoid arthritis. The purpose of this study was to validate a rat pharmacokinetic/pharmacodynamic (PK/PD) model for rapid assessment of drug candidates that intended to interrupt TNFα synthesis or release. Methods Rats received intravenous (IV) or oral administrations of test article or dose vehicle, followed by LPS challenge. Plasma levels of test article and TNFα were determined. The areas under the concentration–time curves (AUCdrug and AUCTNFα) were calculated. The overall percentage of inhibition on TNFα release in vivo was calculated by comparing AUCTNFα of the test article treated group against that for the vehicle control group. Results The dosing vehicles tested in this study did not increase plasma TNFα level. At IV dose of up to 100 μg/kg, LPS did not alter the pharmacokinetics of the compound tested. Using a selective TNFα converting enzyme (TACE) inhibitor as model compound, this PK/PD model demonstrated its ability to correlate plasma test article concentration with its biological activity of lowering the LPS-induced TNFα plasma levels in vivo. Discussion A rat PK/PD model for evaluation of the effect of drug candidates on LPS-induced TNFα synthesis and/or release has been investigated. This model provides integrated information on pharmacokinetics and in vivo potency of the test articles.

A potent, selective series of MMP-13 inhibitors has been derived from a weak (3.2 microM) inhibitor that did not bear a zinc chelator. Structure-based drug design strategies were employed to append a Zn-chelating group to one end of the molecule and functionality to enhance selectivity to the other. A compound from this series demonstrated rat oral bioavailability and efficacy in a bovine articular cartilage explant model.

The SAR of a series of potent sulfonamide hydroxamate TACE inhibitors bearing a butynyloxy P1' group was explored. In particular, compound 5k has excellent in vitro potency against TACE enzyme and in cells, and oral activity in an in vivo model of TNF-alpha production and a collagen-induced arthritis model.

A one‐pot procedure for the efficient sulfonylation of amines with 4‐hydroxybenzenesulfonyl chloride involving in situ protection and deprotection of the phenol with N,O‐bis(trimethylsilyl)acetamide (BTSA) is presented.

Sulfonamide hydroxamate derivatives of anthranilic acids are known to be potent inhibitors of cell-free TACE enzyme. However, compounds of this structural class with both high potency and high selectivity for TACE over matrix metalloproteinases (MMPs) are uncommon. Replacement of the sulfonamide functionality with an isosteric sulfonate ester has resulted in a series of sulfonate ester hydroxamates, 2a-e, with excellent activity against TACE and excellent selectivity over MMP-1 and MMP-13. Although compounds 2a-e possess good permeability in a PAMPA assay, they are only weakly active as inhibitors of lipopolysaccharide (LPS)-stimulated tumor necrosis factor (TNF) production in human monocytic THP-1 cells. Protein binding affinity also does not predict the lack of cellular activity for these analogs.

Three different classes of aryl hydroxamic acid scaffolds have been explored and provided potent inhibitors of MMP-1, -2, -9, -13 and TACE. Structure-based design has allowed the evolution of these inhibitors from broad spectrum inhibitors into compounds that are more selective for MMPs relevant to particular disease states. Aryl hydroxamates selective for MMP-9, MMP-13 and TACE have been disclosed that may aid in the study of the physiological role of these enzymes. Furthermore, the different selectivity profiles offered by these MMP/TACE inhibitors may allow the determination of which metalloprotease, or group of metalloproteases, must be inhibited for the safe, long-term treatment of osteoarthritis, rheumatoid arthritis and cancer. Some of these compounds have demonstrated useful biological activity in efficacy models relevant to osteoarthritis and rheumatoid arthritis and are therefore potential clinical candidates.

Inhibitors of matrix metalloprotease (MMP)-13 and tumor necrosis factor-alpha converting enzyme (TACE) have been highly sought as potential therapeutic agents for the treatment of osteoarthritis and rheumatoid arthritis, respectively. This review focuses on the published literature on these inhibitors from 2001 to mid-2003. Significant advances have been reported in the design and synthesis of potent and selective inhibitors of MMP-13 using hydroxamic acid and non-hydroxamate zinc chelators on a variety of scaffolds. TACE inhibitors based on variations of known MMP inhibitors scaffolds and novel designs have been reported. Selectivity profiles for these inhibitors range from broad-spectrum to TACE-specific. Future clinical studies on these and other inhibitors will determine which MMP, or set of MMPs, must be inhibited for efficacy and long-term safety.

The SAR of a series of potent sulfonamide hydroxamate TACE inhibitors, all bearing a butynyloxy P1' group, was explored. In particular, compound 5j has excellent in vitro potency against isolated TACE enzyme and in cells, good selectivity over MMP-1 and MMP-9, and oral activity in an in vivo model of TNF-alpha production and a collagen-induced arthritis model.

Potent and selective bicyclic heteroaryl hydroxamic acid MMP and TACE inhibitors were synthesized by a novel convergent route. Selectivity and efficacy versus MMPs and TACE could be controlled by appropriate substitution on the scaffolds and by variation of the P1' group. Select compounds were found to be effective in in vivo models of arthritis.