ROCK inhibitors 4: Structure-activity relationship studies of 7-azaindole-based rho kinase (ROCK) inhibitors.

Rho kinase (ROCK) inhibitors are of therapeutic value for the treatment of disorders such as hypertension and glaucoma, and potentially of wider use against diseases such as cancer and multiple sclerosis. We previously reported a series of potent and selective ROCK inhibitors based on a substituted 7-azaindole scaffold. Here we extend the SAR exploration of the 7-azaindole series to identify leads for further evaluation. New compounds such as 16, 17, 19, 21 and 22 showed excellent ROCK potency and protein kinase A (PKA) selectivity, combined with microsome and hepatocyte stability.

Darwinian Evolution's First 50 Years of Impact on Medicine and Botany at the University of Toronto, 1859 to 1909.

Prior to Darwin's masterworks, a university professor of medicine's purview generally included the professorship of botany and direction of the botanical gardens. Yet from the landmark 1876 Johns Hopkins model and especially after the 1910 Flexner Report, botany was limited at certain medical schools to (exaggerating somewhat) "decorating their lobbies!" Darwinian-era scientific paradigms spread from continental Europe through promulgators such as Huxley and Osler, transforming laboratory research, disease aetiology, biochemical therapeutics, and clinical "bedside" teaching. Unintended consequences at universities with medical schools might include altered loyalties and resources among competing disciplines. At the University of Toronto, botany vis-à-vis medicine was gradually treated as passé or secondary to zoology for modern, scientific platforms. This pattern was not universal; botany strongholds at universities such as Harvard continued to flourish. Where a negative perspective took hold with evolutionary impacts, botanists' careers became limited and the impetus for maintaining botanic research and teaching facilities such as a university botanical gardens was impaired.

ROCK inhibitors 3: Design, synthesis and structure-activity relationships of 7-azaindole-based Rho kinase (ROCK) inhibitors.

Rho kinase (ROCK) inhibitors are potential therapeutic agents for the treatment of a variety of disorders including hypertension, glaucoma and erectile dysfunction. Here we disclose a series of potent and selective ROCK inhibitors based on a substituted 7-azaindole scaffold. Substitution of the 3-position of 7-azaindole led to compounds such as 37, which possess excellent ROCK inhibitory potency and high selectivity against the closely related kinase PKA.

The Disjointed Historical Trajectory of Anorexia Nervosa Before 1970.

Responses in pre-modern eras to anorexia nervosa (as now understood) varied widely, from religious piety and sanctity through fear and superstition. While noting briefly the limited conceptualizations from pre-modern history this article is primarily focused from the late 19th century, commencing with helpful but tentative formulations of anorexia nervosa for early-modern medicine that were laid out, consistently between themselves, by Lesègue, Gull and Osler. Yet that promising biomedical advent was superseded for more than a half-century by deep, internal divisions and bitter rifts that festered between three medical disciplines: neurology; Freudian psychotherapy; and Kraepelinian biological psychiatry. Mid-20th century developments preceded the 1960-1980s' improved understanding of suffering and movement toward effective remediation introduced by Dr. Hilde Bruch.

Introducing Darwinism to Toronto's post-1887 reconstituted medical school.

Charles Darwin's scientific paradigm was largely welcomed in Canadian academic biology and medicine, while reaction among other faculty and laypeople ranged from interest to outrage. In 1874, Ramsay Wright, a Darwinian-era biologist from Edinburgh, was appointed to the University of Toronto's Chair of Natural History. Over his 38-year career Wright integrated the evolutionary perspective into medical and biology teaching without accentuating its controversial source. He also applied the emerging German experimental research model and laboratory technology. This study identifies five categories of scientific and personal influences upon Wright through archival research on biographical sources and his writings.

Discovery of Novel, Orally Bioavailable Pyrimidine Ether-Based Inhibitors of ELOVL1.

In our efforts to identify novel small molecule inhibitors for the treatment of adrenoleukodystrophy (ALD), we conducted a high-throughput radiometric screen for inhibitors of elongation of very long chain fatty acid 1 (ELOVL1) enzyme. We developed a series of highly potent, central nervous system (CNS)-penetrant pyrimidine ether-based compounds with favorable pharmacokinetics culminating in compound 22. Compound 22 is a selective inhibitor of ELOVL1, reducing C26:0 VLCFA synthesis in ALD patient fibroblasts and lymphocytes in vitro. Compound 22 reduced C26:0 lysophosphatidyl choline (LPC), a subtype of VLCFA, in the blood of ATP binding cassette transporter D1 (ABCD1) KO mice, a murine model of ALD to near wild-type levels. Compound 22 is a low-molecular-weight, potent ELOVL1 inhibitor that may serve as a useful tool for exploring therapeutic approaches to the treatment of ALD.

Discovery and Optimization of Pyrazole Amides as Inhibitors of ELOVL1.

Accumulation of very long chain fatty acids (VLCFAs) due to defects in ATP binding cassette protein D1 (ABCD1) is thought to underlie the pathologies observed in adrenoleukodystrophy (ALD). Pursuing a substrate reduction approach based on the inhibition of elongation of very long chain fatty acid 1 enzyme (ELOVL1), we explored a series of thiazole amides that evolved into compound 27─a highly potent, central nervous system (CNS)-penetrant compound with favorable in vivo pharmacokinetics. Compound 27 selectively inhibits ELOVL1, reducing C26:0 VLCFA synthesis in ALD patient fibroblasts, lymphocytes, and microglia. In mouse models of ALD, compound 27 treatment reduced C26:0 VLCFA concentrations to near-wild-type levels in blood and up to 65% in the brain, a disease-relevant tissue. Preclinical safety findings in the skin, eye, and CNS precluded progression; the origin and relevance of these findings require further study. ELOVL1 inhibition is an effective approach for normalizing VLCFAs in models of ALD.

Discovery of Novel Allosteric HCV NS5B Inhibitors. 2. Lactam-Containing Thiophene Carboxylates.

Lomibuvir (1) is a non-nucleoside, allosteric inhibitor of the hepatitis C virus NS5B polymerase with demonstrated clinical efficacy. Further development efforts within this class of inhibitor focused on improving the antiviral activity and physicochemical and pharmacokinetic properties. Recently, we reported the development of this series, leading to compound 2, a molecule with comparable potency and an improved physicochemical profile relative to 1. Further exploration of the amino amide-derived side chain led to a series of lactam derivatives, inspired by the X-ray crystal structure of related thiophene carboxylate inhibitors. This series, exemplified by 12f, provided 3-5-fold improvement in potency against HCV replication, as measured by replicon assays. The synthesis, structure-activity relationships, in vitro ADME characterization, and in vivo evaluation of this novel series are discussed.

Discovery of Novel Thiophene-Based, Thumb Pocket 2 Allosteric Inhibitors of the Hepatitis C NS5B Polymerase with Improved Potency and Physicochemical Profiles.

The hepatitis C viral proteins NS3/4A protease, NS5B polymerase, and NS5A are clinically validated targets for direct-acting antiviral therapies. The NS5B polymerase may be inhibited directly through the action of nucleosides or nucleotide analogues or allosterically at a number of well-defined sites. Herein we describe the further development of a series of thiophene carboxylate allosteric inhibitors of NS5B polymerase that act at the thumb pocket 2 site. Lomibuvir (1) is an allosteric HCV NS5B inhibitor that has demonstrated excellent antiviral activity and potential clinical utility in combination with other direct acting antiviral agents. Efforts to further explore and develop this series led to compound 23, a compound with comparable potency and improved physicochemical properties.

Design, Synthesis, and Structure-Activity Relationships of Pyridine-Based Rho Kinase (ROCK) Inhibitors.

The Rho kinases (ROCK1 and ROCK2) are highly homologous serine/threonine kinases that act on substrates associated with cellular motility, morphology, and contraction and are of therapeutic interest in diseases associated with cellular migration and contraction, such as hypertension, glaucoma, and erectile dysfunction. Beginning with compound 4, an inhibitor of ROCK1 identified through high-throughput screening, systematic exploration of SAR, and application of structure-based design, led to potent and selective ROCK inhibitors. Compound 37 represents significant improvements in inhibition potency, kinase selectivity, and CYP inhibition and possesses pharmacokinetics suitable for in vivo experimentation.

Discovery of a novel, first-in-class, orally bioavailable azaindole inhibitor (VX-787) of influenza PB2.

In our effort to develop agents for the treatment of influenza, a phenotypic screening approach utilizing a cell protection assay identified a series of azaindole based inhibitors of the cap-snatching function of the PB2 subunit of the influenza A viral polymerase complex. Using a bDNA viral replication assay (Wagaman, P. C., Leong, M. A., and Simmen, K. A. Development of a novel influenza A antiviral assay. J. Virol. Methods 2002, 105, 105-114) in cells as a direct measure of antiviral activity, we discovered a set of cyclohexyl carboxylic acid analogues, highlighted by VX-787 (2). Compound 2 shows strong potency versus multiple influenza A strains, including pandemic 2009 H1N1 and avian H5N1 flu strains, and shows an efficacy profile in a mouse influenza model even when treatment was administered 48 h after infection. Compound 2 represents a first-in-class, orally bioavailable, novel compound that offers potential for the treatment of both pandemic and seasonal influenza and has a distinct advantage over the current standard of care treatments including potency, efficacy, and extended treatment window.

Effective treatment of eating disorders: Results at multiple sites.

We report the results of a study based on 1,428 patients with eating disorders treated at 6 clinics. These patients were consecutively referred over 18 years and used inpatient and outpatient treatment. The subjects were diagnosed with anorexia nervosa, bulimia nervosa, or an eating disorder not otherwise specified. Patients practiced a normal eating pattern with computerized feedback technology, they were supplied with external heat, their physical activity was reduced, and their social habits restored to allow them to return to their normal life. The estimated rate of remission for this therapy was 75% after a median of 12.5 months of treatment. A competing event such as the termination of insurance coverage, or failure of the treatment, interfered with outcomes in 16% of the patients, and the other patients remained in treatment. Of those who went in remission, the estimated rate of relapse was 10% over 5 years of follow-up and there was no mortality. These data replicate the outcomes reported in our previous studies and they compare favorably with the poor long-term remission rates, the high rate of relapse, and the high mortality rate reported with standard treatments for eating disorders.

An innovative treatment programme for anorexia nervosa.

We present the case of an Australian girl with severe anorexia nervosa who had previously been resistant to treatment, and who was subsequently treated successfully by an innovative programme at the Karolinska Institute in Stockholm. The programme is based on a distinctive concept of causation of eating disorders in which it is postulated that they develop as a consequence of starvation rather than a primary mental disorder. The treatment focuses on relearning how to eat and perceive satiety using a unique feed-back system, together with provision of warmth, limitation of exercise and facilitating social adaptation.

Inhibitors of hepatitis C virus NS3.4A protease. Part 3: P2 proline variants.

We recently described the identification of an optimized alpha-ketoamide warhead for our series of HCV NS3.4A inhibitors. We report herein a series of HCV protease inhibitors incorporating 3-alkyl-substituted prolines in P(2). These compounds show exceptional enzymatic and cellular potency given their relatively small size. The marked enhancement of activity of these 3-substituted proline derivatives relative to previously reported 4-hydroxyproline derivatives constitutes additional evidence for the importance of the S(2) binding pocket as the defining pharmacophore for inhibition of the NS3.4A enzyme.

Inhibitors of hepatitis C virus NS3.4A protease 2. Warhead SAR and optimization.

The alpha-ketoamide warhead (e.g., 15) was found to be a practical replacement for aliphatic aldehydes in a series of HCV NS3.4A protease inhibitors. Structure-activity relationships and prime side optimization are discussed.

Inhibitors of hepatitis C virus NS3.4A protease 1. Non-charged tetrapeptide variants.

Tetrapeptide-based peptidomimetic compounds have been shown to effectively inhibit the hepatitis C virus NS3.4A protease without the need of a charged functionality. An aldehyde is used as a prototype reversible electrophilic warhead. The SAR of the P1 and P2 inhibitor positions is discussed.