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Bhattacharjee P, Rutland N, Iyer MR. Targeting Sterol O-Acyltransferase/Acyl-CoA:Cholesterol Acyltransferase (ACAT): A Perspective on Small-Molecule Inhibitors and Their Therapeutic Potential. J Med Chem 2022; 65:16062-16098. [PMID: 36473091 DOI: 10.1021/acs.jmedchem.2c01265] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Sterol O-acyltransferase (SOAT) is a membrane-bound enzyme that aids the esterification of cholesterol and fatty acids to cholesterol esters. SOAT has been studied extensively as a potential drug target, since its inhibition can serve as an alternative to statin therapy. Two SOAT isozymes that have discrete functions in the human body, namely, SOAT1 and SOAT2, have been characterized. Over three decades of research has focused on candidate SOAT1 inhibitors with unsatisfactory results in clinical trials. Recent research has focused on targeting SOAT2 selectively. In this perspective, we summarize the literature covering various SOAT inhibitory agents and discuss the design, structural requirements, and mode of action of SOAT inhibitors.
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Affiliation(s)
- Pinaki Bhattacharjee
- Section on Medicinal Chemistry, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, 5625 Fishers Lane, Rockville, Maryland 20852, United States
| | - Nicholas Rutland
- Section on Medicinal Chemistry, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, 5625 Fishers Lane, Rockville, Maryland 20852, United States
| | - Malliga R Iyer
- Section on Medicinal Chemistry, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, 5625 Fishers Lane, Rockville, Maryland 20852, United States
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2
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Hill J, Shao X, Wright JS, Stauff J, Sherman PS, Arteaga J, Wong KK, Viglianti BL, Scott PJH, Brooks AF. Synthesis and Evaluation of 11C- and 18F-Labeled SOAT1 Inhibitors as Macrophage Foam Cell Imaging Agents. ACS Med Chem Lett 2020; 11:1299-1304. [PMID: 32551015 PMCID: PMC7294710 DOI: 10.1021/acsmedchemlett.0c00127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 04/30/2020] [Indexed: 11/30/2022] Open
Abstract
PD-132301, an inhibitor of sterol O-acyltransferase 1 (SOAT1; also known as acyl-coenzyme A:cholesterol acyltransferase-1, ACAT1), is under clinical investigation for numerous adrenal disorders. Radiolabeled SOAT1 inhibitors could support drug discovery and help diagnose SOAT1-related disorders, such as atherosclerosis. We synthesized two radiolabeled SOAT1 inhibitors, [11C]PD-132301 and fluorine analogue [18F]1. Rat biodistribution studies were conducted with both agents and, as the most selective tracer, [11C]PD-132301 was advanced to preclinical positron emission tomography studies in (atherosclerotic) ApoE-/- mice. The uptake of [11C]PD-132301 in SOAT1-rich tissue warrants further investigation into the compound as an atherosclerosis and adrenal imaging agent.
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Affiliation(s)
- James
R. Hill
- Institute
for Molecular Bioscience, The University
of Queensland, Brisbane, Queensland 4072, Australia
- Department
of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Xia Shao
- Department
of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Jay S. Wright
- Department
of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Jenelle Stauff
- Department
of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Phillip S. Sherman
- Department
of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Janna Arteaga
- Department
of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Ka Kit Wong
- Department
of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Benjamin L. Viglianti
- Department
of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
- Nuclear
Medicine Service, Veterans Administration, Ann Arbor, Michigan 48105, United States
| | - Peter J. H. Scott
- Department
of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Allen F. Brooks
- Department
of Radiology, University of Michigan, Ann Arbor, Michigan 48109, United States
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3
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Shibuya K, Kawamine K, Ozaki C, Ohgiya T, Edano T, Yoshinaka Y, Tsunenari Y. Discovery of Clinical Candidate 2-(4-(2-((1H-Benzo[d]imidazol-2-yl)thio)ethyl)piperazin-1-yl)-N-(6-methyl-2,4-bis(methylthio)pyridin-3-yl)acetamide Hydrochloride [K-604], an Aqueous-Soluble Acyl-CoA:Cholesterol O-Acyltransferase-1 Inhibitor. J Med Chem 2018; 61:10635-10650. [DOI: 10.1021/acs.jmedchem.8b01256] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Kimiyuki Shibuya
- Tokyo New Drug Research Laboratories, Pharmaceutical Division, Kowa Company, Ltd., 2-17-43, Noguchicho,
Higashimurayama, Tokyo 189-0022, Japan
| | - Katsumi Kawamine
- Tokyo New Drug Research Laboratories, Pharmaceutical Division, Kowa Company, Ltd., 2-17-43, Noguchicho,
Higashimurayama, Tokyo 189-0022, Japan
| | - Chiyoka Ozaki
- Tokyo New Drug Research Laboratories, Pharmaceutical Division, Kowa Company, Ltd., 2-17-43, Noguchicho,
Higashimurayama, Tokyo 189-0022, Japan
| | - Tadaaki Ohgiya
- Tokyo New Drug Research Laboratories, Pharmaceutical Division, Kowa Company, Ltd., 2-17-43, Noguchicho,
Higashimurayama, Tokyo 189-0022, Japan
| | - Toshiyuki Edano
- Tokyo New Drug Research Laboratories, Pharmaceutical Division, Kowa Company, Ltd., 2-17-43, Noguchicho,
Higashimurayama, Tokyo 189-0022, Japan
| | - Yasunobu Yoshinaka
- Tokyo New Drug Research Laboratories, Pharmaceutical Division, Kowa Company, Ltd., 2-17-43, Noguchicho,
Higashimurayama, Tokyo 189-0022, Japan
| | - Yoshihiko Tsunenari
- Tokyo New Drug Research Laboratories, Pharmaceutical Division, Kowa Company, Ltd., 2-17-43, Noguchicho,
Higashimurayama, Tokyo 189-0022, Japan
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4
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Shibuya K, Kawamine K, Miura T, Ozaki C, Edano T, Mizuno K, Yoshinaka Y, Tsunenari Y. Design, synthesis and pharmacology of aortic-selective acyl-CoA: Cholesterol O-acyltransferase (ACAT/SOAT) inhibitors. Bioorg Med Chem 2018; 26:4001-4013. [DOI: 10.1016/j.bmc.2018.06.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 06/14/2018] [Accepted: 06/16/2018] [Indexed: 10/28/2022]
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5
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Langlois DK, Fritz MC, Schall WD, Bari Olivier N, Smedley RC, Pearson PG, Bailie MB, Hunt SW. ATR-101, a selective ACAT1 inhibitor, decreases ACTH-stimulated cortisol concentrations in dogs with naturally occurring Cushing's syndrome. BMC Endocr Disord 2018; 18:24. [PMID: 29720169 PMCID: PMC5932779 DOI: 10.1186/s12902-018-0251-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 04/26/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cushing's syndrome in humans shares many similarities with its counterpart in dogs in terms of etiology (pituitary versus adrenal causes), clinical signs, and pathophysiologic sequelae. In both species, treatment of pituitary- and adrenal-dependent disease is met with limitations. ATR-101, a selective inhibitor of ACAT1 (acyl coenzyme A:cholesterol acyltransferase 1), is a novel small molecule therapeutic currently in clinical development for the treatment of adrenocortical carcinoma, congenital adrenal hyperplasia, and Cushing's syndrome in humans. Previous studies in healthy dogs have shown that ATR-101 treatment led to rapid, dose-dependent decreases in adrenocorticotropic hormone (ACTH) stimulated cortisol levels. The purpose of this clinical study was to investigate the effects of ATR-101 in dogs with Cushing's syndrome. METHODS ATR-101 pharmacokinetics and activity were assessed in 10 dogs with naturally-occurring Cushing's syndrome, including 7 dogs with pituitary-dependent disease and 3 dogs with adrenal-dependent disease. ATR-101 was administered at 3 mg/kg PO once daily for one week, followed by 30 mg/kg PO once daily for one (n = 4) or three (n = 6) weeks. Clinical, biochemical, adrenal hormonal, and pharmacokinetic data were obtained weekly for study duration. RESULTS ATR-101 exposure increased with increasing dose. ACTH-stimulated cortisol concentrations, the primary endpoint for the study, were significantly decreased with responders (9 of 10 dogs) experiencing a mean ± standard deviation reduction in cortisol levels of 50 ± 17% at study completion. Decreases in pre-ACTH-stimulated cortisol concentrations were observed in some dogs although overall changes in pre-ACTH cortisol concentrations were not significant. The compound was well-tolerated and no serious drug-related adverse effects were reported. CONCLUSIONS This study highlights the potential utility of naturally occurring canine Cushing's syndrome as a model for human disease and provides proof of concept for ATR-101 as a novel agent for the treatment of endocrine disorders like Cushing's syndrome in humans.
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Affiliation(s)
- Daniel K Langlois
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, 48824, USA.
| | - Michele C Fritz
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, 48824, USA
- Present address: College of Human Medicine, Michigan State University, East Lansing, MI, 48824, USA
| | - William D Schall
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, 48824, USA
| | - N Bari Olivier
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, 48824, USA
| | - Rebecca C Smedley
- Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Michigan State University, East Lansing, MI, 48824, USA
| | - Paul G Pearson
- Pearson Pharma Partners, Inc., Los Angeles, California, 91362, USA
| | - Marc B Bailie
- Integrated Non-Clinical Development Solutions, Inc., Ann Arbor, MI, 48103, USA
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6
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Burns VE, Kerppola TK. ATR-101 inhibits cholesterol efflux and cortisol secretion by ATP-binding cassette transporters, causing cytotoxic cholesterol accumulation in adrenocortical carcinoma cells. Br J Pharmacol 2017; 174:3315-3332. [PMID: 28710789 DOI: 10.1111/bph.13951] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 06/22/2017] [Accepted: 07/07/2017] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND AND PURPOSE To further the development of new agents for the treatment of adrenocortical carcinoma (ACC), we characterized the molecular and cellular mechanisms of cytotoxicity by the adrenalytic compound ATR-101 (PD132301-02). EXPERIMENTAL APPROACH We compared the effects of ATR-101, PD129337, and ABC transporter inhibitors on cholesterol accumulation and efflux, on cortisol secretion, on ATP levels, and on caspase activation in ACC-derived cell lines. We examined the effects of these compounds in combination with methyl-β-cyclodextrin or exogenous cholesterol to determine the roles of altered cholesterol levels in the effects of these compounds. KEY RESULTS ATR-101 caused cholesterol accumulation, ATP depletion, and caspase activation within 30 minutes after addition to ACC-derived cells, whereas PD129337 did not. Suppression of cholesterol accumulation by methyl-β-cyclodextrin or exogenous cholesterol, prevented ATP depletion and caspase activation by ATR-101. ATR-101 blocked cholesterol efflux and cortisol secretion, suggesting that it inhibited ABCA1, ABCG1, and MDR1 transporters. Combinations of ABCA1, ABCG1, and MDR1 inhibitors were also cytotoxic. Combinations of ATR-101 with inhibitors of ABCG1, MDR1, or mitochondrial functions had increased cytotoxicity. Inhibitors of steroidogenesis reduced ATP depletion by ATR-101, whereas U18666A enhanced cholesterol accumulation and ATP depletion together with ATR-101. ATR-101 repressed ABCA1, ABCG1, and IDOL transcription by mechanisms that were distinct from the mechanisms that caused cholesterol accumulation. CONCLUSIONS AND IMPLICATIONS Inhibition of multiple ABC transporters and the consequent accumulation of cholesterol mediated the cytotoxicity of ATR-101. Compounds that replicate these effects in tumours are likely to be useful in the treatment of ACC.
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Affiliation(s)
| | - Tom Klaus Kerppola
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA
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7
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Kroiss M, Fassnacht M. Inhibition of Cholesterol Esterification in the Adrenal Gland by ATR101/PD132301-2, A Promising Case of Drug Repurposing. Endocrinology 2016; 157:1719-21. [PMID: 27149038 DOI: 10.1210/en.2016-1210] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Matthias Kroiss
- Division of Endocrinology and Diabetology, Department of Internal Medicine, University Hospital Würzburg, University of Würzburg; and Clinical Chemistry and Laboratory Medicine, University Hospital Würzburg; and Comprehensive Cancer Center Mainfranken, University of Würzburg, 97080 Würzburg, Germany
| | - Martin Fassnacht
- Division of Endocrinology and Diabetology, Department of Internal Medicine, University Hospital Würzburg, University of Würzburg; and Clinical Chemistry and Laboratory Medicine, University Hospital Würzburg; and Comprehensive Cancer Center Mainfranken, University of Würzburg, 97080 Würzburg, Germany
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8
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Cheng Y, Kerppola RE, Kerppola TK. ATR-101 disrupts mitochondrial functions in adrenocortical carcinoma cells and in vivo. Endocr Relat Cancer 2016; 23:1-19. [PMID: 26843528 PMCID: PMC4887102 DOI: 10.1530/erc-15-0527] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 02/02/2016] [Indexed: 12/26/2022]
Abstract
Adrenocortical carcinoma (ACC) generally has poor prognosis. Existing treatments provide limited benefit for most patients with locally advanced or metastatic tumors. We investigated the mechanisms for the cytotoxicity, xenograft suppression, and adrenalytic activity of ATR-101 (PD132301-02), a prospective agent for ACC treatment. Oral administration of ATR-101 inhibited the establishment and impeded the growth of ACC-derived H295R cell xenografts in mice. ATR-101 induced H295R cell apoptosis in culture and in xenografts. ATR-101 caused mitochondrial hyperpolarization, reactive oxygen release, and ATP depletion within hours after exposure, followed by cytochrome c release, caspase-3/7 activation, and membrane permeabilization. The increase in mitochondrial membrane potential occurred concurrently with the decrease in cellular ATP levels. When combined with ATR-101, lipophilic free radical scavengers suppressed the reactive oxygen release, and glycolytic precursors prevented the ATP depletion, abrogating ATR-101 cytotoxicity. ATR-101 directly inhibited F1F0-ATPase activity and suppressed ATP synthesis in mitochondrial fractions. ATR-101 administration to guinea pigs caused oxidized lipofuscin accumulation in the zona fasciculate layer of the adrenal cortex, implicating reactive oxygen release in the adrenalytic effect of ATR-101. These results support the development of ATR-101 and other adrenalytic compounds for the treatment of ACC.
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Affiliation(s)
- Yunhui Cheng
- Department of Biological ChemistryUniversity of Michigan, Ann Arbor, MI, USA
| | | | - Tom Klaus Kerppola
- Department of Biological ChemistryUniversity of Michigan, Ann Arbor, MI, USA
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9
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Saito Y, Segawa Y, Itami K. para-C-H Borylation of Benzene Derivatives by a Bulky Iridium Catalyst. J Am Chem Soc 2015; 137:5193-8. [PMID: 25860511 DOI: 10.1021/jacs.5b02052] [Citation(s) in RCA: 177] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A highly para-selective aromatic C-H borylation has been accomplished. By a new iridium catalyst bearing a bulky diphosphine ligand, Xyl-MeO-BIPHEP, the C-H borylation of monosubstituted benzenes can be affected with para-selectivity up to 91%. This catalytic system is quite different from the usual iridium catalysts that cannot distinguish meta- and para-C-H bonds of monosubstituted benzene derivatives, resulting in the preferred formation of meta-products. The para-selectivity increases with increasing bulkiness of the substituent on the arene, indicating that the regioselectivity of the present reaction is primarily controlled by steric repulsion between substrate and catalyst. Caramiphen, an anticholinergic drug used in the treatment of Parkinson's disease, was converted into five derivatives via our para-selective borylation. The present [Ir(cod)OH]2/Xyl-MeO-BIPHEP catalyst represents a unique, sterically controlled, para-selective, aromatic C-H borylation system that should find use in streamlined, predictable chemical synthesis and in the rapid discovery and optimization of pharmaceuticals and materials.
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Affiliation(s)
- Yutaro Saito
- †Graduate School of Science, ‡JST, ERATO, Itami Molecular Nanocarbon Project, and §Institute of Transformative Bio-molecules (WPI-ITbM), Nagoya University, Chikusa, Nagoya 464-8602, Japan
| | - Yasutomo Segawa
- †Graduate School of Science, ‡JST, ERATO, Itami Molecular Nanocarbon Project, and §Institute of Transformative Bio-molecules (WPI-ITbM), Nagoya University, Chikusa, Nagoya 464-8602, Japan
| | - Kenichiro Itami
- †Graduate School of Science, ‡JST, ERATO, Itami Molecular Nanocarbon Project, and §Institute of Transformative Bio-molecules (WPI-ITbM), Nagoya University, Chikusa, Nagoya 464-8602, Japan
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Matsuda D, Ohshiro T, Ohtawa M, Yamazaki H, Nagamitsu T, Tomoda H. In vitro metabolism of pyripyropene A and ACAT inhibitory activity of its metabolites. J Antibiot (Tokyo) 2015; 68:27-34. [PMID: 25005817 DOI: 10.1038/ja.2014.91] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 05/12/2014] [Accepted: 06/10/2014] [Indexed: 11/09/2022]
Abstract
Pyripyropene A (PPPA, 1) of fungal origin, a selective inhibitor of acyl-CoA:cholesterol acyltransferase 2 (ACAT2), proved orally active in atherogenic mouse models. The in vitro metabolites of 1 in liver microsomes and plasma of human, rabbit, rat and mouse were analyzed by ultra fast liquid chromatography and liquid chromatography/tandem mass spectrometry. In the liver microsomes from all species, successive hydrolysis occurred at the 1-O-acetyl residue, then at the 11-O-acetyl residue of 1, while the 7-O-acetyl residue was resistant to hydrolysis. Furthermore, dehydrogenation of the newly generated 11-alcoholic hydroxyl residue occurred in human and mouse-liver microsomes, while oxidation of the pyridine ring occurred in human and rabbit liver microsomes. On the other hand, hydrolysis of the 7-O-acetyl residue proceeded only in the mouse plasma. These data indicated that the in vitro metabolic profiles of 1 have subtle differences among animal species. All of the PPPA metabolites observed in liver microsomes and plasma markedly decreased ACAT2 inhibitory activity. These findings will help us to synthesize new PPPA derivatives more effective in in vivo study than 1.
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Affiliation(s)
- Daisuke Matsuda
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
| | - Taichi Ohshiro
- 1] Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan [2] Section on Lipid Sciences, Department of Pathology, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Masaki Ohtawa
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
| | - Hiroyuki Yamazaki
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
| | - Tohru Nagamitsu
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
| | - Hiroshi Tomoda
- Graduate School of Pharmaceutical Sciences, Kitasato University, Tokyo, Japan
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Matralis AN, Kourounakis AP. Design of Novel Potent Antihyperlipidemic Agents with Antioxidant/Anti-inflammatory Properties: Exploiting Phenothiazine’s Strong Antioxidant Activity. J Med Chem 2014; 57:2568-81. [DOI: 10.1021/jm401842e] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alexios N. Matralis
- Department of Medicinal Chemistry,
School of Pharmacy, University of Athens, 15771 Athens, Greece
| | - Angeliki P. Kourounakis
- Department of Medicinal Chemistry,
School of Pharmacy, University of Athens, 15771 Athens, Greece
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12
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Isoform-specific inhibitors of ACATs: recent advances and promising developments. Future Med Chem 2011; 3:2039-61. [DOI: 10.4155/fmc.11.158] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Acyl-CoA:cholesterol acyltransferase (ACAT) is a promising therapeutic target for cardiovascular diseases. Although a number of synthetic ACAT inhibitors have been developed, they have failed to show efficacy in clinical trials. Now, the presence of two ACAT isoforms with distinct functions, ACAT1 and ACAT2, has been discovered. Thus, the selectivity of ACAT inhibitors toward the two isoforms is important for their development as novel anti-atherosclerotic agents. The selectivity study indicated that fungal pyripyropene A (PPPA) is only an ACAT2-specific inhibitor. Furthermore, PPPA proved orally active in atherogenic mouse models, indicating it possessed cholesterol-lowering and atheroprotective activities. Certain PPPA derivatives, semi-synthetically prepared, possessed more potent and selective in vitro activity than PPPA against ACAT2. This review covers these studies and describes the future prospects of ACAT2-specific inhibitors.
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13
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Ohshiro T, Matsuda D, Sakai K, Degirolamo C, Yagyu H, Rudel LL, Omura S, Ishibashi S, Tomoda H. Pyripyropene A, an acyl-coenzyme A:cholesterol acyltransferase 2-selective inhibitor, attenuates hypercholesterolemia and atherosclerosis in murine models of hyperlipidemia. Arterioscler Thromb Vasc Biol 2011; 31:1108-15. [PMID: 21393580 DOI: 10.1161/atvbaha.111.223552] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Pyripyropene A (PPPA) of fungal origin is the first compound that has been found to strongly and selectively inhibit acyl-coenzyme A:cholesterol acyltransferase 2 (ACAT2) isozyme activity in vitro. The purpose of the present study was to investigate in vivo efficacy of the ACAT2-selective inhibitor in atherosclerosis. METHODS AND RESULTS PPPA treatment (10 to 100 mg/kg) caused 30.5±4.7% to 55.8±3.3% inhibition of the cholesterol absorption from the mouse intestine. When PPPA (10 to 50 mg/kg per day) was orally administered to apolipoprotein E-knockout mice for 12 weeks, the levels of plasma cholesterol, very-low-density lipoprotein (VLDL), and low-density lipoprotein (LDL) and hepatic cholesterol content were lowered. Furthermore, the ratio of cholesteryl oleate (exclusively synthesized in hepatic ACAT2) to cholesteryl linoleate in VLDL- and LDL-derived cholesteryl ester decreased, indicating that hepatic ACAT2 activity was inhibited by PPPA. PPPA-treated mice had reduced atherogenic lesion areas that were lowered by 26.2±3.7% to 46±3.8% in the aortae and by 18.9±3.6% to 37.6±6.0% in the hearts. CONCLUSIONS Our findings indicate that ACAT2-selective inhibition in the intestine and the liver can be effective against atherosclerosis and that PPPA appears to be a potential antiatherogenic lead compound. This study is the first demonstration of the in vivo efficacy of PPPA, an ACAT2-selective inhibitor, in atherosclerosis. PPPA-treated atherogenic mice showed a decrease in intestinal cholesterol absorption and cholesterol and cholesteryl oleate levels in both LDL and VLDL, resulting in protection of atherosclerosis development.
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Affiliation(s)
- Taichi Ohshiro
- Department of Microbial Chemistry, Graduate School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
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14
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Bellina F, Cauteruccio S, Rossi R. Synthesis and biological activity of vicinal diaryl-substituted 1H-imidazoles. Tetrahedron 2007. [DOI: 10.1016/j.tet.2007.02.075] [Citation(s) in RCA: 164] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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15
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Leon C, Hill JS, Wasan KM. Potential role of acyl-coenzyme A:cholesterol transferase (ACAT) Inhibitors as hypolipidemic and antiatherosclerosis drugs. Pharm Res 2005; 22:1578-88. [PMID: 16180116 DOI: 10.1007/s11095-005-6306-0] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2005] [Accepted: 06/03/2005] [Indexed: 11/29/2022]
Abstract
Acyl-coenzyme A:cholesterol transferase (ACAT) is an integral membrane protein localized in the endoplasmic reticulum. ACAT catalyzes the formation of cholesteryl esters from cholesterol and fatty acyl coenzyme A. The cholesteryl esters are stored as cytoplasmic lipid droplets inside the cell. This process is very important to the organism as high cholesterol levels have been associated with cardiovascular disease. In mammals, two ACAT genes have been identified, ACAT1 and ACAT2. ACAT1 is ubiquitous and is responsible for cholesteryl ester formation in brain, adrenal glands, macrophages, and kidneys. ACAT2 is expressed in the liver and intestine. The inhibition of ACAT activity has been associated with decreased plasma cholesterol levels by suppressing cholesterol absorption and by diminishing the assembly and secretion of apolipoprotein B-containing lipoproteins such as very low density lipoprotein (VLDL). ACAT inhibition also prevents the conversion of macrophages into foam cells in the arterial walls, a critical event in the development of atherosclerosis. This review paper will focus on the role of ACAT in cholesterol metabolism, in particular as a target to develop novel therapeutic agents to control hypercholesterolemia, atherosclerosis, and Alzheimer's disease.
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Affiliation(s)
- Carlos Leon
- Division of Pharmaceutics and Biopharmaceutics, Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
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16
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Gelain A. Pyridazine derivatives as novel acyl-coa:cholesterol acyltransferase (acat) inhibitors. J Heterocycl Chem 2005. [DOI: 10.1002/jhet.5570420306] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Ohnuma S, Muraoka M, Ioriya K, Ohashi N. Synthesis and structure–activity relationship studies on a novel series of naphthylidinoylureas as inhibitors of acyl-CoA:cholesterol O -acyltransferase (ACAT). Bioorg Med Chem Lett 2004; 14:1309-11. [PMID: 14980688 DOI: 10.1016/j.bmcl.2003.12.045] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2003] [Accepted: 12/05/2003] [Indexed: 11/19/2022]
Abstract
The synthesis and structure-activity relationships of N-phenyl-N'-[3-(4-phenylnaphthylidinoyl)]urea derivatives 3 as a novel structural class of potent ACAT inhibitors is described. A 3-methoxy group substituted on the naphthylidinone 4-phenyl ring, together with a 1-N-(n)butyl substitution, SM-32504 (3m), gave a potent ACAT inhibitor, in vitro, respectively. The most potent compound, SM-32504 (3m), decreased the serum cholesterol level significantly in a high fat and high cholesterol-fed mouse model.
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Affiliation(s)
- Satoshi Ohnuma
- Research Division, Sumitomo Pharmaceuticals Co. Ltd, 1-98 Kasugade Naka 3-chome, Konohana-ku, Osaka 554-0022, Japan.
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18
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Sliskovic DR, Picard JA, Krause BR. ACAT inhibitors: the search for a novel and effective treatment of hypercholesterolemia and atherosclerosis. PROGRESS IN MEDICINAL CHEMISTRY 2003; 39:121-71. [PMID: 12536672 DOI: 10.1016/s0079-6468(08)70070-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Drago R Sliskovic
- Pfizer Global Research and Development, Ann Arbor Laboratories, 2800 Plymouth Road, Ann Arbor, Michigan 48105, USA
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19
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Ohishi K, Aiyama R, Hatano H, Yoshida Y, Wada Y, Yokoi W, Sawada H, Watanabe T, Yokokura T. Structure-activity relationships of N-(3,5-dimethoxy-4-n-octyloxycinnamoyl)-N'-(3,4-dimethylphenyl)piperazine and analogues as inhibitors of acyl-CoA: cholesterol O-acyltransferase. Chem Pharm Bull (Tokyo) 2001; 49:830-9. [PMID: 11456087 DOI: 10.1248/cpb.49.830] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A novel series of acyl-CoA: cholesterol O-acyltransferase (ACAT) inhibitors were synthesized from a lead compound, 1-(4-hydroxy-3-methoxyphenyl)-7-phenylhept-1-en-3-one (1, Yakuchinone B) through a modification of three regions (A, B, C) in the molecule. In this study, the compounds prepared were tested for in vitro inhibitory activity on microsomal ACAT from the liver of rats and for in vivo hypocholesterolemic activity in rats given a high cholesterol diet. N-(3,5-Dimethoxy-4-n-octyloxycinnamoyl)-N'-(3,4-dimethylphenyl)piperazine (45), which belongs to the amide compounds, has finally been discovered. Compound 45 inhibited rat hepatic ACAT in a more striking manner than CI-976, an amide compound ACAT inhibitor, and it exhibited a high level of hypocholesterolemic activity in vivo. Since 45 strongly inhibited both microsomal ACAT prepared from HepG2 (a cell line derived from human hepatocarcinoma) and Caco2 (a cell line derived from human colon adenocarcinoma), there is speculation that 45 might have the ability to inhibit ACAT in both the human intestine and liver independent of the difference in the distribution of ACAT isozymes. On the other hand, 45 did not induce adrenotoxicity in subacute toxicity studies in rats. These results suggest that it has promise for development as a new therapeutic agent for hypercholesterolemia and atherosclerosis.
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Affiliation(s)
- K Ohishi
- Yakult Central Institute for Microbiological Research, Kunitachi, Tokyo, Japan.
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20
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Tanaka A, Terasawa T, Hagihara H, Ishibe N, Sawada M, Sakuma Y, Hashimoto M, Takasugi H, Tanaka H. Inhibitors of acyl-CoA:cholesterol O-acyltransferase. 3. Discovery of a novel series of N-alkyl-N-[(fluorophenoxy)benzyl]-N'-arylureas with weak toxicological effects on adrenal glands. J Med Chem 1998; 41:4408-20. [PMID: 9784116 DOI: 10.1021/jm980399q] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of N-alkyl-N-[(fluorophenoxy)benzyl]-N'-arylureas were prepared and evaluated for their ability to inhibit intestinal acyl-CoA:cholesterol O-acyltransferase and to inhibit accumulation of cholesteryl esters in macrophages in vitro. In vivo hypocholesterolemic activity was assessed in cholesterol-fed rats by oral administration as a dietary admixture and/or by gavage in a PEG400 vehicle. Modification of the alkyl substituent on the N'-aryl moiety and on the urea nitrogen significantly influenced macrophage assay in vitro. Toxicological study revealed a distinct relationship between macrophage assay and the toxicity observed in adrenal glands of rabbits treated with representatives of this series of compounds. Investigations utilizing the macrophage assay as an indicator for adrenal toxicity led to the identification of compounds 1g (FR190809) and 1k (FR186485, or FR195249 as its hydrochloride salt) as potent, nonadrenotoxic, orally efficacious ACAT inhibitors irrespective of the administration method.
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Affiliation(s)
- A Tanaka
- Medicinal Chemistry Research Laboratories, Medicinal Biology Research Laboratories, Fujisawa Pharmaceutical Company Ltd., 2-1-6 Kashima, Yodogawa-ku, Osaka 532-8514, Japan
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21
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Tanaka A, Terasawa T, Hagihara H, Sakuma Y, Ishibe N, Sawada M, Takasugi H, Tanaka H. Inhibitors of acyl-CoA:cholesterol O-acyltransferase. 2. Identification and structure-activity relationships of a novel series of N-alkyl-N-(heteroaryl-substituted benzyl)-N'-arylureas. J Med Chem 1998; 41:2390-410. [PMID: 9632372 DOI: 10.1021/jm9800853] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A series of N-alkyl-N-(heteroaryl-substituted benzyl)-N'-arylurea and related derivatives represented by 2 and 3 have been prepared and evaluated for their ability to inhibit acyl-CoA:cholesterol O-acyltransferase in vitro and to lower plasma cholesterol levels in cholesterol-fed rats in vivo. Among these novel compounds, the type 3 series was superior. A pyrazol-3-yl group on the N-benzyl group of this trisubstituted urea (i.e. 3, Ar1 = pyrazol-3-yl) was identified as a heteroaromatic ring providing a good profile of biological activity. As a result of optimization of the combination with the N-alkyl group (R) and N-aryl group (Ar3), compound 3aq (FR186054) was identified as a new, orally efficacious ACAT inhibitor, which exhibited potent in vitro ACAT inhibitory activity (rabbit intestinal microsomes IC50 = 99 nM) and excellent hypocholesterolemic effects in cholesterol-fed rats, irrespective of administration mode (ED50 = 0.046 mg/kg dosed via the diet, ED50 = 0. 44 mg/kg administered by gavage in PEG400 vehicle). Moreover, a toxicological study revealed compound 3aq to be nontoxic to the adrenal glands of dogs when tested at a single dose of 10 mg/kg po.
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Affiliation(s)
- A Tanaka
- Medicinal Chemistry Research Laboratories, Medicinal Biology Research Laboratories, and New Drug Research Laboratories, Fujisawa Pharmaceutical Co. Ltd., 2-1-6 Kashima, Yodogawa-ku, Osaka 532, Japan
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22
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Sliskovic DR, Picard JA, O'Brien PM, Liao P, Roark WH, Roth BD, Anderson MA, Mueller SB, Bocan TM, Bousley RF, Hamelehle KL, Homan R, Reindel JF, Stanfield RL, Turluck D, Krause BR. alpha-Substituted malonester amides: tools to define the relationship between ACAT inhibition and adrenal toxicity. J Med Chem 1998; 41:682-90. [PMID: 9513596 DOI: 10.1021/jm970560h] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We prepared a series of alpha-substituted malonester amides that were evaluated for their ability to inhibit acyl-CoA:cholesterol O-acyl transferase activity in vitro and to lower plasma total cholesterol levels in a variety of cholesterol-fed animal models. Compounds of this series were also useful in examining the relationship between adrenal toxicity and ACAT inhibition. One compound from this series, 9f, was a potent inhibitor of ACAT in both the microsomal and cellular assays. It was also bioavailable as determined by both a bioassay and a HPLC-UV assay. This compound was evaluated in both guinea pig and dog models of adrenal toxicity and compared to tetrazole amide 15. In the most sensitive species, the dog, both of these compounds achieved good plasma levels; however, compound 9f caused adrenal necrosis, whereas compound 15 had no effect on the adrenal gland. This adds to the growing body of evidence that the adrenal toxicity observed with ACAT inhibitors may not be mechanism related.
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Affiliation(s)
- D R Sliskovic
- Parke-Davis Pharmaceutical Research Division, Warner-Lambert Company, Ann Arbor, Michigan 48105, USA
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23
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Tanaka A, Terasawa T, Hagihara H, Kinoshita T, Sakuma Y, Ishibe N, Sawada M, Takasugi H, Tanaka H. Synthesis, X-ray crystal structure, and biological activity of FR186054, a novel, potent, orally active inhibitor of acyl-CoA:cholesterol O-acyltransferase (ACAT) bearing a pyrazole ring. Bioorg Med Chem Lett 1998; 8:81-6. [PMID: 9871633 DOI: 10.1016/s0960-894x(97)10191-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The synthesis, single crystal X-ray structural analysis, and biological activity of FR186054 (2c), a new, potent, orally efficacious inhibitor of acyl-CoA:cholesterol O-acyltransferase (ACAT), containing a pyrazole ring are described. This compound displayed excellent in vitro efficacy, irrespective of dosing method, indicating superior characteristics compared to other ACAT inhibitors.
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Affiliation(s)
- A Tanaka
- Medicinal Chemistry Research Laboratories, Fujisawa Pharmaceutical Co. Ltd., Osaka, Japan
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24
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Tanaka A, Terasawa T, Hagihara H, Sakuma Y, Ishibe N, Sawada M, Takasugi H, Tanaka H. Inhibitors of acyl-CoA:cholesterol O-acyltransferase (ACAT). Part 1: identification and structure-activity relationships of a novel series of substituted N-alkyl-N-biphenylylmethyl-N'-arylureas. Bioorg Med Chem 1998; 6:15-30. [PMID: 9502102 DOI: 10.1016/s0968-0896(97)10009-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A series of N-alkyl-N-biphenylylmethyl-N'-arylurea and related derivatives represented by 1 have been prepared and evaluated for their ability to inhibit acyl-CoA:cholesterol O-acyltransferase in vitro and to lower plasma cholesterol levels in cholesterol-fed rats in vivo. Linking of two phenyl groups via oxygen and introduction of fluorine at appropriate positions on the biphenyl moiety improved in vitro and in vivo activity. From this series of analogs, compound 40 (FR179254), which had potent in vitro potency (rabbit intestinal microsomes IC50 = 25 nM), showed excellent plasma cholesterol-lowering activity when administered via the diet (ED50 = 0.045 mg/kg). However, the hypocholesterolemic effect of this compound was moderate when dosed by oral gavage in PEG400 as a vehicle (ED50 = 5.3 mg/kg). Modification of the N'-aryl moiety led to the identification of compound 50 (FR182980) which was efficacious in both dosing models (ED50 = 0.034 mg/kg and 0.11 mg/kg, respectively).
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Affiliation(s)
- A Tanaka
- Medicinal Chemistry Research Laboratories, Fujisawa Pharmaceutical Co. Ltd., Osaka, Japan
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25
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Roth BD. ACAT inhibitors: evolution from cholesterol-absorption inhibitors to antiatherosclerotic agents. Drug Discov Today 1998. [DOI: 10.1016/s1359-6446(97)01123-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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26
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Purchase TS, Essenburg AD, Hamelehle KL, Hes MS, Holmes A, Krause BR, Stanfield RL, Trivedi BK. Inhibitors of acyl-CoA:cholesterol acyltransferase: novel trisubstituted ureas as hypocholesterolemic agents. Bioorg Med Chem 1997; 5:739-47. [PMID: 9158873 DOI: 10.1016/s0968-0896(97)00019-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Our continued interest in developing novel, potent acyl-CoA:cholesterol acyltransferase (ACAT) inhibitors, and our discovery of several active series of disubstituted urea ACAT inhibitors, have led us to investigate a series of trisubstituted ureas that are structural hybrids of our disubstituted series and of a trisubstituted urea ACAT inhibitor series disclosed by scientists at Lederle. This investigation has led to the discovery of novel trisubstituted ureas, several of which inhibit ACAT in the nanomolar range and effectively lower total plasma cholesterol when administered as a diet admixture in an acute model of hypercholesterolemia in rats. One analogue (35) also lowered total cholesterol as efficaciously as CL 277,082 in our chronic hypercholesterolemic rat model. The most notable finding of this study is that the SAR of the trisubstituted ureas diverges from that seen in our previously disclosed disubstituted urea series. This series showed optimal activity with 2,4-difluoro and 2,4,6-trifluoro substitution on the urea N-phenyl, whereas the disubstituted series showed optimal activity with bulky 2,6-disubstitution on the phenyl ring.
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Affiliation(s)
- T S Purchase
- Department of Medicinal Chemistry, Parke-Davis Pharmaceutical Research, Division of Warner-Lambert Company, Ann Arbor, MI 48105, USA
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27
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White AD, Creswell MW, Chucholowski AW, Blankley CJ, Wilson MW, Bousley RF, Essenburg AD, Hamelehle KL, Krause BR, Stanfield RL, Dominick MA, Neub M. Heterocyclic ureas: inhibitors of acyl-CoA:cholesterol O-acyltransferase as hypocholesterolemic agents. J Med Chem 1996; 39:4382-95. [PMID: 8893833 DOI: 10.1021/jm960404v] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A series of diaryl-substituted heterocyclic ureas was prepared, and their ability to inhibit acyl-CoA: cholesterol O-acyltransferase (ACAT) in vitro and to lower plasma total cholesterol in cholesterol-fed animal models in vivo was examined. N-(2,6-Diisopropylphenyl)-N'-tetrazole or isoxazole-substituted heterocyclic ureas proved optimal. A carbon chain of 11-14 carbons substituted 1,3 with respect to the amine provided the optimal side chain. Substitution of the alkyl chain generally lowered activity. Tetrazole urea 2i dosed at 3 mg/kg lowered plasma total cholesterol (TC) 67% in an acute, cholesterol-fed (C-fed) rat model of hypercholesterolemia and 47% in C-fed dogs. Tetrazole 2i, dosed at 10 mg/kg, also lowered TC 52% and raised HDL cholesterol 113% in rats with pre-established hypercholesterolemia.
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Affiliation(s)
- A D White
- Department of Medicinal Chemistry, Division of Warner-Lambert Company, Ann Arbor, Michigan 48105, USA
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28
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White AD, Purchase CF, Picard JA, Anderson MK, Mueller SB, Bocan TM, Bousley RF, Hamelehle KL, Krause BR, Lee P, Stanfield RL, Reindel JF. Heterocyclic amides: inhibitors of acyl-CoA:cholesterol O-acyl transferase with hypocholesterolemic activity in several species and antiatherosclerotic activity in the rabbit. J Med Chem 1996; 39:3908-19. [PMID: 8831757 DOI: 10.1021/jm9604033] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A series of heterocyclic amides were synthesized and evaluated as inhibitors of acyl-CoA: cholesterol O-acyltransferase (ACAT) in vitro and for cholesterol lowering in cholesterol-fed rats. Compounds were evaluated for cell-based macrophage ACAT inhibition, bioactivity, and adrenal toxicity. Candidates were selected for evaluation in cholesterol-fed dogs and, ultimately, the injured cholesterol-fed rabbit model of atherosclerosis. The heterocyclic amides potently inhibited rabbit liver ACAT (IC50's = 0.014-0.11 microM), and the majority of compounds significantly lowered plasma cholesterol (42-68%) in an acute cholesterol-fed rat model at 3 mg/kg. The most efficacious compounds in the rat were evaluated for bioactivity in vivo and arterial ACAT inhibition in a cell-based macrophage ACAT assay. Two highly bioactive analogs, (+/-)-2-(3-dodecylisoxazol-5-yl)-2-phenyl-N-(2,4,6-trimethoxypheny l) acetamide (13a) and (+/-)-2-(5-dodecylisoxazol-3-yl)-2-phenyl-N-(2,4,6-trimethoxypheny l) acetamide (16a), were selected for further study and were found to be nontoxic in a guinea pig model of adrenal toxicity. Compounds 13a and 16a lowered total cholesterol in the cholesterol-fed rat, rabbit, and dog models of pre-established hypercholesterolemia. Compound 13a in the injured cholesterol-fed rabbit model of atherosclerosis was effective in slowing the development of cholesteryl ester-rich thoracic aortic lesions, reducing lesion coverage by 53% at a dose of 1 mg/kg.
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Affiliation(s)
- A D White
- Department of Medicinal Chemistry, Parke-Davis Pharmaceutical Research, Division of Warner-Lambert Company, Ann Arbor, Michigan 48105, USA
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29
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Wilde RG, Billheimer JT, Germain SJ, Hausner EA, Meunier PC, Munzer DA, Stoltenborg JK, Gillies PJ, Burcham DL, Huang SM, Klaczkiewicz JD, Ko SS, Wexler RR. ACAT inhibitors derived from hetero-Diels-Alder cycloadducts of thioaldehydes. Bioorg Med Chem 1996; 4:1493-513. [PMID: 8894107 DOI: 10.1016/0968-0896(96)00143-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Acyl-CoA:cholesterol acyltransferase (ACAT) is the enzyme largely responsible for intracellular cholesterol esterification. A systemic inhibitor of ACAT is believed to be able to slow or even reverse the atherosclerotic process. Towards that goal, a series of cyclic sulfides, derived from the hetero-Diels-Alder reaction of thioaldehydes with 1,3-dienes, and bearing carboxamide substituents, were prepared and evaluated for in vitro (in several tissues and species) and ex vivo ACAT inhibition. Minor changes in subsequent structure were found to have a significant effect in optimization of the biological activity of this series of compounds.
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Affiliation(s)
- R G Wilde
- DuPont Merck Pharmaceutical Company, DuPont Experimental Station, Wilmington, DE 19880-0500, USA
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30
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Astles PC, Ashton MJ, Bridge AW, Harris NV, Hart TW, Parrott DP, Porter B, Riddell D, Smith C, Williams RJ. Acyl-CoA:Cholesterol O-acyltransferase (ACAT) inhibitors. 2. 2-(1,3-Dioxan-2-yl)-4,5-diphenyl-1H-imidazoles as potent inhibitors of ACAT. J Med Chem 1996; 39:1423-32. [PMID: 8691472 DOI: 10.1021/jm9505876] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The second in this series of papers concerns our further investigations into the search for a potent bioavailable acyl-CoA:cholesterol O-acyltransferase (ACAT) inhibitor suitable for the treatment of atherosclerosis. The design, synthesis, and structure-activity relationship for a series of ACAT inhibitors based on the 2-(1,3-dioxan-2-yl)-4,5-diphenyl-1H-imidazole pharmacophore are described. Compounds such as 13a bearing simple alkyl or hydroxymethyl substituents at the 5-position of the 1,3-dioxane ring are potent bioavailable inhibitors of the rat hepatic microsomal enzyme in vitro (IC50 < 100 nM) but are only weak inhibitors of the human hepatic enzyme. We have found however that 1,3-dioxanes substituted at the 5-cis position with pyrazolylalkyl or aminoalkyl groups are potent inhibitors in vitro of human macrophage ACAT, the potency depending on the nature of the terminal heterocycle and the length of the alkyl chain. An ex vivo bioassay herein demonstrates that potent inhibitors such as 13t (IC50 = 10 nM) which contain lipophilic terminal heterocycles do not appear to be systematically available. Less potent but more water soluble compounds such as 13h (IC50 = 60 nM) and 13n (IC50 = 70 nM) are absorbed following oral dosing and achieve plasma levels significantly in excess of their IC50 for ACAT inhibition. These compounds are therefore possible candidates for further investigation as oral antiatherosclerotic agents.
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Affiliation(s)
- P C Astles
- Rhône-Poulenc Rorer, Dagenham Research Centre, Dagenham, Essex, U.K
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31
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32
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Harte RA, Yeaman SJ, Jackson B, Suckling KE. Effect of membrane environment on inhibition of acyl-CoA:cholesterol acyltransferase by a range of synthetic inhibitors. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1258:241-50. [PMID: 7548193 DOI: 10.1016/0005-2760(95)00113-q] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The effect of the membrane environment of acyl-CoA:cholesterol acyl transferase (ACAT), an important intracellular enzyme of cholesterol metabolism, on the properties of a range of inhibitors of varying potencies was studied. ACAT activity from rat liver was solubilised with 3% deoxycholate (97% solubilised activity). After dilution into cholesterol/phosphatidylcholine liposomes (molar ratio 0.35), the assay of this reconstituted system showed linearity with protein and time. Saturation with oleoyl-CoA was achieved at 10 microM. Comparison of the potency of the ACAT inhibitors in the reconstituted assay and in a microsomal assay revealed a relationship between the lipid content of the assay and the inhibitory activity for potent inhibitors of ACAT (CI976, CL277,082, YMI7E and DuP128). This relationship was unrelated to lipophilicity of the drugs. Octimibate, lovastatin and progesterone, none of which is a potent ACAT inhibitor but which have all been described as ACAT inhibitors in the literature, all had low potencies in both assay systems. These results suggest that the lipid concentration must be taken into account when comparing potencies of ACAT inhibitors. The present data also indicate that some compounds which inhibit cholesterol esterification may do so by an indirect mechanism.
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Affiliation(s)
- R A Harte
- Department of Biochemistry and Genetics, Medical School, University of Newcastle, Newcastle upon Tyne, UK
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33
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Trivedi BK, Holmes A, Purchase TS, Essenburg AD, Hamelehle KL, Krause BR, Hes MS, Stanfield RL. A series of conformationally and sterically constrained analogs of N-phenyl-N′-aralkylurea ACAT inhibitors. Bioorg Med Chem Lett 1995. [DOI: 10.1016/0960-894x(95)00387-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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34
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Dugar S, Davis HR, Burrier RE, Salisbury BG. Amides of piperidine, morpholine and piperazine substituted 1-phenylethylamines: inhibitors of acylCoA:cholesterol acyltransferase (ACAT) activity in vitro and in vivo. Bioorg Med Chem 1995; 3:1231-6. [PMID: 8564414 DOI: 10.1016/0968-0896(95)00092-u] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Amides of some substituted 1,2-diarylethylamines have been shown to exhibit potent acylCoA:cholesterol acyltransferase (ACAT, EC 2.3.1.26) inhibitory activity in vitro in microsomal ACAT assays but show poor in vivo activity in a cholesterol-fed hamster model. In an effort to design ACAT inhibitors that are potent in both our in vitro and in vivo assays a series of amides of piperidine, morpholine and piperazine substituted 1-phenylethylamines were synthesized. Compounds of this series were found to be very potent inhibitors of ACAT in a microsomal ACAT assay and also exhibited potent activity in a cholesterol-fed hamster model.
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Affiliation(s)
- S Dugar
- Schering-Plough Research Institute, Kenilworth, NJ 07033-0539, USA
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35
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O'Brien PM, Sliskovic DR, Anderson MK, Bousley RF, Krause BR, Stanfield RL. Inhibitors of acyl-CoA: Cholesterol O-acyl transferase (ACAT) as hypocholesterolemic agents. 12. Syntheses and biological activity of structurally novel tetrazole amides. Bioorg Med Chem Lett 1995. [DOI: 10.1016/0960-894x(95)00024-n] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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36
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Roark WH, Padia J, Bolton GL, Blankley CJ, Essenburg AD, Stanfield RL, Bousley RF, Krause BR, Roth BD. Bioisosterism in drug design: identification of and structure-activity relationships in a series of glycine anilide ACAT inhibitors. Bioorg Med Chem 1995; 3:29-39. [PMID: 8612044 DOI: 10.1016/0968-0896(94)00144-r] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
To examine the effects of bioisosteric replacement on the biological activity of our previously disclosed disubstituted urea inhibitors of the enzyme acyl-CoA:cholesterol acyltransferase (ACAT), we prepared a series of N'-substituted and N',N'-disubstituted glycine anilides. These compounds were tested for the ability to inhibit ACAT in vitro and lower plasma total cholesterol in cholesterol-fed rats given a single high-fat, high-cholesterol meal. ACAT inhibitory potency was greatest in compounds containing 2,6-diisopropyl substituents in the anilide portion with the glycine nitrogen substituted by a 1,1-diphenylmethyl moiety. Small improvements in potency in vitro were obtained by substitution of electron donating groups in the 2-, 3- or 5-positions of the aryl rings of the 1,1-diphenylmethyl moiety, but not by substitution in the 4-position. In vitro potency was maintained, but not improved by acylation of the glycine nitrogen. Through a QSAR analysis of in vitro ACAT inhibition for this set of compounds, an equation could be derived which accounted for 85% of the variance in the dataset. An optimal clogp of 6.65 was found, comparable to that found for other series of ACAT inhibitors. In general, compounds from this series displayed inhibitory potency against ACAT in vitro and hypocholesterolemic activity in the in vivo rat model of hypercholesterolemia comparable to that found with the ureas.
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Affiliation(s)
- W H Roark
- Department of Medicinal Chemistry, Parke-Davis Pharmaceutical Research, Division of Warner-Lambert Company, Ann Arbor, MI 48105, USA
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