Lysophospholipase-like 1 (LYPLAL1) is an uncharacterized metabolic serine hydrolase. Human genome... more Lysophospholipase-like 1 (LYPLAL1) is an uncharacterized metabolic serine hydrolase. Human genome-wide association studies link variants of the gene encoding this enzyme to fat distribution, waist-to-hip ratio and non-alcoholic fatty liver disease. We describe the discovery of potent and selective covalent small-molecule inhibitors of LYPLAL1 and their use to investigate its role in hepatic metabolism. In hepatocytes, selective inhibition of LYPLAL1 increased glucose production supporting the inference that LYPLAL1 is a significant actor in hepatic metabolism. The results provide an example of how a selective chemical tool can contribute to evaluating a hypothetical target for therapeutic intervention, even in the absence of complete biochemical characterization.
Objective Recent studies suggest that excess dietary fructose contributes to metabolic dysfunctio... more Objective Recent studies suggest that excess dietary fructose contributes to metabolic dysfunction by promoting insulin resistance, de novo lipogenesis (DNL), and hepatic steatosis, thereby increasing the risk of obesity, type 2 diabetes (T2D), non-alcoholic steatohepatitis (NASH), and related comorbidities. Whether this metabolic dysfunction is driven by the excess dietary calories contained in fructose or whether fructose catabolism itself is uniquely pathogenic remains controversial. We sought to test whether a small molecule inhibitor of the primary fructose metabolizing enzyme ketohexokinase (KHK) can ameliorate the metabolic effects of fructose. Methods The KHK inhibitor PF-06835919 was used to block fructose metabolism in primary hepatocytes and Sprague Dawley rats fed either a high-fructose diet (30% fructose kcal/g) or a diet reflecting the average macronutrient dietary content of an American diet (AD) (7.5% fructose kcal/g). The effects of fructose consumption and KHK inhibition on hepatic steatosis, insulin resistance, and hyperlipidemia were evaluated, along with the activation of DNL and the enzymes that regulate lipid synthesis. A metabolomic analysis was performed to confirm KHK inhibition and understand metabolite changes in response to fructose metabolism in vitro and in vivo. Additionally, the effects of administering a single ascending dose of PF-06835919 on fructose metabolism markers in healthy human study participants were assessed in a randomized placebo-controlled phase 1 study. Results Inhibition of KHK in rats prevented hyperinsulinemia and hypertriglyceridemia from fructose feeding. Supraphysiologic levels of dietary fructose were not necessary to cause metabolic dysfunction as rats fed the American diet developed hyperinsulinemia, hypertriglyceridemia, and hepatic steatosis, which were all reversed by KHK inhibition. Reversal of the metabolic effects of fructose coincided with reductions in DNL and inactivation of the lipogenic transcription factor carbohydrate response element-binding protein (ChREBP). We report that administering single oral doses of PF-06835919 was safe and well tolerated in healthy study participants and dose-dependently increased plasma fructose indicative of KHK inhibition. Conclusions Fructose consumption in rats promoted features of metabolic dysfunction seen in metabolic diseases such as T2D and NASH, including insulin resistance, hypertriglyceridemia, and hepatic steatosis, which were reversed by KHK inhibition.
Increased fructose consumption and its subsequent metabolism have been implicated in metabolic di... more Increased fructose consumption and its subsequent metabolism have been implicated in metabolic disorders such as non-alcoholic fatty liver disease and steatohepatitis (NAFLD/NASH) and insulin resistance. Ketohexokinase (KHK) converts fructose to fructose-1phosphate (F1P) in the first step of the metabolic cascade. Herein we report the discovery of a first-in-class KHK inhibitor, PF-06835919 (8), currently in phase 2 clinical trials. The discovery of 8 was built upon our originally reported, fragment-derived lead 1 and the recognition of an alternative, rotated binding mode upon changing the ribose-pocket binding moiety from a pyrrolidinyl to an azetidinyl ring system. This new binding mode enabled efficient exploration of the vector directed at the Arg-108 residue, leading to the identification of highly potent 3azabicyclo[3.1.0]hexane acetic acid-based KHK inhibitors by combined use of parallel medicinal chemistry and structure-based drug design.
Increased fructose consumption and its subsequent metabolism have been implicated in hepatic stea... more Increased fructose consumption and its subsequent metabolism have been implicated in hepatic steatosis, dyslipidemia, obesity and insulin resistance in humans. Since ketohexokinase (KHK) is the principal enzyme responsible for fructose metabolism, identification of a selective KHK inhibitor may help to further elucidate the effect of KHK inhibition on these metabolic disorders. Until now, studies on KHK inhibition with small molecules have been limited due to the lack of viable in vivo pharmacological tools. Herein we report the discovery of 12, a selective KHK inhibitor with potency and properties suitable to evaluate KHK inhibition in rat models. Key structural features interacting with KHK were discovered through fragment-based screening and subsequent optimization using structure-based drug design and parallel medicinal chemistry led to the identification of pyridine 12.
Inhibition of the sodium-coupled citrate transporter (NaCT or SLC13A5) has been proposed as a new... more Inhibition of the sodium-coupled citrate transporter (NaCT or SLC13A5) has been proposed as a new therapeutic approach for prevention and treatment of metabolic diseases. In a previous report, we discovered dicarboxylate 1a (PF-06649298) which inhibits the transport of citrate in in vitro and in vivo settings via a specific interaction with NaCT. Herein, we report the optimization of this series leading to 4a (PF-06761281), a more potent inhibitor with suitable in vivo pharmacokinetic profile for assessment of in vivo pharmacodynamics. Compound 4a was used to demonstrate dose-dependent inhibition of radioactive [(14)C]-citrate uptake in liver and kidney in vivo, resulting in modest reductions in plasma glucose concentrations.
Abstract Labdane diterpene acids were found to be the major resin acid components in Pinus nigra ... more Abstract Labdane diterpene acids were found to be the major resin acid components in Pinus nigra needles of various seed sources. The major constituents have been identified as 4-epiimbricataloic acid, manoyl oxide 19-oic acid, 4-epicommunic acid, and 15-monomethyl pinifolate. A GC method was developed to analytically differentiate pinifolic acid from its monomethyl ester in an admixture of both compounds. A minor resin acid was identified as 18-acetoxy-8(17)-labden-15-oic acid. 10-Nonacosanol and isoabienol were identified as major constituents of the needle and cortex extractives, respectively.
Bioorganic & Medicinal Chemistry Letters, 2015
Protein-protein interactions (PPIs) present a formidable challenge to medicinal chemistry. The ex... more Protein-protein interactions (PPIs) present a formidable challenge to medicinal chemistry. The extended and open nature of many binding sites at protein interfaces has made it difficult to find useful chemical matter by traditional screening methods using standard screening libraries. This Digest focuses on the progress that has been made in discovering small-molecule modulators for a diverse selection of PPI targets using fragment screening and highlights the utility of this strategy in this context.
Cardiovascular diseases (CVDs) are the number one cause of death globally according to the World ... more Cardiovascular diseases (CVDs) are the number one cause of death globally according to the World Health Organization. They account for approximately 30% of all global deaths and incur great medical costs. Chronic or congestive heart failure (CHF) remains the most prevalent diagnosis requiring hospitalization. Current treatments for heart failure patients aim to improve quality of life by treating signs and symptoms but patient outcomes remain poor. Discovery and development of new heart failure therapies is an active research area seeking to address this unmet medical need. In this chapter, we review (1) new drugs in the clinic for existing targets and (2) new targets that are currently being evaluated in the clinic. Topics include new mechanistic and clinical research of the renin–angiotensin–aldosterone pathway, inotropes and treatments for dyslipidemia. In addition, novel mechanisms for heart failure including drugs targeting mitochondrial function, inflammatory pathways as well as kinase inhibitors are discussed.
ABSTRACT Process development and the multikilogram synthesis of a novel azetidinyl ketolide antib... more ABSTRACT Process development and the multikilogram synthesis of a novel azetidinyl ketolide antibiotic is described. Starting with clarithromycin, the eight-step synthesis features several telescoped operations and direct isolations, which results in a significant improvement in throughput and a major reduction in solvent usage and waste stream volume over the first scale-up campaign. Particular highlights of this effort include the development of an efficient synthesis of 3-hydroxy-1,5-naphthyridine-4-carbaldehyde via a Skraup process and engineering a robust final API synthesis. We also discovered a crystalline monotosylate salt that addressed significant formulation and degradation issues experienced when using the noncrystalline freebase.
We report novel syntheses of 12-membered macrocyclic templates and a library of 4000 macrocyclic ... more We report novel syntheses of 12-membered macrocyclic templates and a library of 4000 macrocyclic analogs. The key macrocyclization step was performed at up to 100 g scale without resorting to syringe pumps, flow reactors or large volumes of solvent. An interesting observation of considerably different permeability properties was made on diastereomeric analogs due to differences in intramolecular hydrogen bond interactions.
... Soc. 86 (1964), p. 4438. d) M. Dobler, JD Dunitz, B. Gubler, HP Weber, G. Büchi and O. Padill... more ... Soc. 86 (1964), p. 4438. d) M. Dobler, JD Dunitz, B. Gubler, HP Weber, G. Büchi and O. Padilla, J. Proc. Chem. Soc. ... Soc 97 (1975), p. 891. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (68). EJ Corey, JA Katzenellenbogen and GH Posner, J. Am. Chem. ...
Supplementary Material Available: General procedure for the preparation of NMR samples, NMR peak ... more Supplementary Material Available: General procedure for the preparation of NMR samples, NMR peak listings with assignments, and ' H and 13C spectra (13 pages). Ordering information is given on any current masthead page. Thus, it is the compiexation, not the oxidation, which is enantioselective. The (R,R)-DIPT-based Katsuki-Sharpless complex will give well-defined complexes with
Lysophospholipase-like 1 (LYPLAL1) is an uncharacterized metabolic serine hydrolase. Human genome... more Lysophospholipase-like 1 (LYPLAL1) is an uncharacterized metabolic serine hydrolase. Human genome-wide association studies link variants of the gene encoding this enzyme to fat distribution, waist-to-hip ratio and non-alcoholic fatty liver disease. We describe the discovery of potent and selective covalent small-molecule inhibitors of LYPLAL1 and their use to investigate its role in hepatic metabolism. In hepatocytes, selective inhibition of LYPLAL1 increased glucose production supporting the inference that LYPLAL1 is a significant actor in hepatic metabolism. The results provide an example of how a selective chemical tool can contribute to evaluating a hypothetical target for therapeutic intervention, even in the absence of complete biochemical characterization.
Objective Recent studies suggest that excess dietary fructose contributes to metabolic dysfunctio... more Objective Recent studies suggest that excess dietary fructose contributes to metabolic dysfunction by promoting insulin resistance, de novo lipogenesis (DNL), and hepatic steatosis, thereby increasing the risk of obesity, type 2 diabetes (T2D), non-alcoholic steatohepatitis (NASH), and related comorbidities. Whether this metabolic dysfunction is driven by the excess dietary calories contained in fructose or whether fructose catabolism itself is uniquely pathogenic remains controversial. We sought to test whether a small molecule inhibitor of the primary fructose metabolizing enzyme ketohexokinase (KHK) can ameliorate the metabolic effects of fructose. Methods The KHK inhibitor PF-06835919 was used to block fructose metabolism in primary hepatocytes and Sprague Dawley rats fed either a high-fructose diet (30% fructose kcal/g) or a diet reflecting the average macronutrient dietary content of an American diet (AD) (7.5% fructose kcal/g). The effects of fructose consumption and KHK inhibition on hepatic steatosis, insulin resistance, and hyperlipidemia were evaluated, along with the activation of DNL and the enzymes that regulate lipid synthesis. A metabolomic analysis was performed to confirm KHK inhibition and understand metabolite changes in response to fructose metabolism in vitro and in vivo. Additionally, the effects of administering a single ascending dose of PF-06835919 on fructose metabolism markers in healthy human study participants were assessed in a randomized placebo-controlled phase 1 study. Results Inhibition of KHK in rats prevented hyperinsulinemia and hypertriglyceridemia from fructose feeding. Supraphysiologic levels of dietary fructose were not necessary to cause metabolic dysfunction as rats fed the American diet developed hyperinsulinemia, hypertriglyceridemia, and hepatic steatosis, which were all reversed by KHK inhibition. Reversal of the metabolic effects of fructose coincided with reductions in DNL and inactivation of the lipogenic transcription factor carbohydrate response element-binding protein (ChREBP). We report that administering single oral doses of PF-06835919 was safe and well tolerated in healthy study participants and dose-dependently increased plasma fructose indicative of KHK inhibition. Conclusions Fructose consumption in rats promoted features of metabolic dysfunction seen in metabolic diseases such as T2D and NASH, including insulin resistance, hypertriglyceridemia, and hepatic steatosis, which were reversed by KHK inhibition.
Increased fructose consumption and its subsequent metabolism have been implicated in metabolic di... more Increased fructose consumption and its subsequent metabolism have been implicated in metabolic disorders such as non-alcoholic fatty liver disease and steatohepatitis (NAFLD/NASH) and insulin resistance. Ketohexokinase (KHK) converts fructose to fructose-1phosphate (F1P) in the first step of the metabolic cascade. Herein we report the discovery of a first-in-class KHK inhibitor, PF-06835919 (8), currently in phase 2 clinical trials. The discovery of 8 was built upon our originally reported, fragment-derived lead 1 and the recognition of an alternative, rotated binding mode upon changing the ribose-pocket binding moiety from a pyrrolidinyl to an azetidinyl ring system. This new binding mode enabled efficient exploration of the vector directed at the Arg-108 residue, leading to the identification of highly potent 3azabicyclo[3.1.0]hexane acetic acid-based KHK inhibitors by combined use of parallel medicinal chemistry and structure-based drug design.
Increased fructose consumption and its subsequent metabolism have been implicated in hepatic stea... more Increased fructose consumption and its subsequent metabolism have been implicated in hepatic steatosis, dyslipidemia, obesity and insulin resistance in humans. Since ketohexokinase (KHK) is the principal enzyme responsible for fructose metabolism, identification of a selective KHK inhibitor may help to further elucidate the effect of KHK inhibition on these metabolic disorders. Until now, studies on KHK inhibition with small molecules have been limited due to the lack of viable in vivo pharmacological tools. Herein we report the discovery of 12, a selective KHK inhibitor with potency and properties suitable to evaluate KHK inhibition in rat models. Key structural features interacting with KHK were discovered through fragment-based screening and subsequent optimization using structure-based drug design and parallel medicinal chemistry led to the identification of pyridine 12.
Inhibition of the sodium-coupled citrate transporter (NaCT or SLC13A5) has been proposed as a new... more Inhibition of the sodium-coupled citrate transporter (NaCT or SLC13A5) has been proposed as a new therapeutic approach for prevention and treatment of metabolic diseases. In a previous report, we discovered dicarboxylate 1a (PF-06649298) which inhibits the transport of citrate in in vitro and in vivo settings via a specific interaction with NaCT. Herein, we report the optimization of this series leading to 4a (PF-06761281), a more potent inhibitor with suitable in vivo pharmacokinetic profile for assessment of in vivo pharmacodynamics. Compound 4a was used to demonstrate dose-dependent inhibition of radioactive [(14)C]-citrate uptake in liver and kidney in vivo, resulting in modest reductions in plasma glucose concentrations.
Abstract Labdane diterpene acids were found to be the major resin acid components in Pinus nigra ... more Abstract Labdane diterpene acids were found to be the major resin acid components in Pinus nigra needles of various seed sources. The major constituents have been identified as 4-epiimbricataloic acid, manoyl oxide 19-oic acid, 4-epicommunic acid, and 15-monomethyl pinifolate. A GC method was developed to analytically differentiate pinifolic acid from its monomethyl ester in an admixture of both compounds. A minor resin acid was identified as 18-acetoxy-8(17)-labden-15-oic acid. 10-Nonacosanol and isoabienol were identified as major constituents of the needle and cortex extractives, respectively.
Bioorganic & Medicinal Chemistry Letters, 2015
Protein-protein interactions (PPIs) present a formidable challenge to medicinal chemistry. The ex... more Protein-protein interactions (PPIs) present a formidable challenge to medicinal chemistry. The extended and open nature of many binding sites at protein interfaces has made it difficult to find useful chemical matter by traditional screening methods using standard screening libraries. This Digest focuses on the progress that has been made in discovering small-molecule modulators for a diverse selection of PPI targets using fragment screening and highlights the utility of this strategy in this context.
Cardiovascular diseases (CVDs) are the number one cause of death globally according to the World ... more Cardiovascular diseases (CVDs) are the number one cause of death globally according to the World Health Organization. They account for approximately 30% of all global deaths and incur great medical costs. Chronic or congestive heart failure (CHF) remains the most prevalent diagnosis requiring hospitalization. Current treatments for heart failure patients aim to improve quality of life by treating signs and symptoms but patient outcomes remain poor. Discovery and development of new heart failure therapies is an active research area seeking to address this unmet medical need. In this chapter, we review (1) new drugs in the clinic for existing targets and (2) new targets that are currently being evaluated in the clinic. Topics include new mechanistic and clinical research of the renin–angiotensin–aldosterone pathway, inotropes and treatments for dyslipidemia. In addition, novel mechanisms for heart failure including drugs targeting mitochondrial function, inflammatory pathways as well as kinase inhibitors are discussed.
ABSTRACT Process development and the multikilogram synthesis of a novel azetidinyl ketolide antib... more ABSTRACT Process development and the multikilogram synthesis of a novel azetidinyl ketolide antibiotic is described. Starting with clarithromycin, the eight-step synthesis features several telescoped operations and direct isolations, which results in a significant improvement in throughput and a major reduction in solvent usage and waste stream volume over the first scale-up campaign. Particular highlights of this effort include the development of an efficient synthesis of 3-hydroxy-1,5-naphthyridine-4-carbaldehyde via a Skraup process and engineering a robust final API synthesis. We also discovered a crystalline monotosylate salt that addressed significant formulation and degradation issues experienced when using the noncrystalline freebase.
We report novel syntheses of 12-membered macrocyclic templates and a library of 4000 macrocyclic ... more We report novel syntheses of 12-membered macrocyclic templates and a library of 4000 macrocyclic analogs. The key macrocyclization step was performed at up to 100 g scale without resorting to syringe pumps, flow reactors or large volumes of solvent. An interesting observation of considerably different permeability properties was made on diastereomeric analogs due to differences in intramolecular hydrogen bond interactions.
... Soc. 86 (1964), p. 4438. d) M. Dobler, JD Dunitz, B. Gubler, HP Weber, G. Büchi and O. Padill... more ... Soc. 86 (1964), p. 4438. d) M. Dobler, JD Dunitz, B. Gubler, HP Weber, G. Büchi and O. Padilla, J. Proc. Chem. Soc. ... Soc 97 (1975), p. 891. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (68). EJ Corey, JA Katzenellenbogen and GH Posner, J. Am. Chem. ...
Supplementary Material Available: General procedure for the preparation of NMR samples, NMR peak ... more Supplementary Material Available: General procedure for the preparation of NMR samples, NMR peak listings with assignments, and ' H and 13C spectra (13 pages). Ordering information is given on any current masthead page. Thus, it is the compiexation, not the oxidation, which is enantioselective. The (R,R)-DIPT-based Katsuki-Sharpless complex will give well-defined complexes with
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