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Olivo G, Capocasa G, Ticconi B, Lanzalunga O, Di Stefano S, Costas M. Predictable Selectivity in Remote C−H Oxidation of Steroids: Analysis of Substrate Binding Mode. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202003078] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Giorgio Olivo
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química Universitat de Girona Campus de Montilivi, C/ Pic de Peguera 15 17003 Girona Spain
| | - Giorgio Capocasa
- Dipartimento di Chimica and Istituto CNR per i Sistemi Biologici (ISB-CNR) Sezione Meccanismi di Reazione Sapienza Università di Roma P. le A. Moro 5 00185 Rome Italy
| | - Barbara Ticconi
- Dipartimento di Chimica and Istituto CNR per i Sistemi Biologici (ISB-CNR) Sezione Meccanismi di Reazione Sapienza Università di Roma P. le A. Moro 5 00185 Rome Italy
| | - Osvaldo Lanzalunga
- Dipartimento di Chimica and Istituto CNR per i Sistemi Biologici (ISB-CNR) Sezione Meccanismi di Reazione Sapienza Università di Roma P. le A. Moro 5 00185 Rome Italy
| | - Stefano Di Stefano
- Dipartimento di Chimica and Istituto CNR per i Sistemi Biologici (ISB-CNR) Sezione Meccanismi di Reazione Sapienza Università di Roma P. le A. Moro 5 00185 Rome Italy
| | - Miquel Costas
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química Universitat de Girona Campus de Montilivi, C/ Pic de Peguera 15 17003 Girona Spain
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2
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Olivo G, Capocasa G, Ticconi B, Lanzalunga O, Di Stefano S, Costas M. Predictable Selectivity in Remote C−H Oxidation of Steroids: Analysis of Substrate Binding Mode. Angew Chem Int Ed Engl 2020; 59:12703-12708. [DOI: 10.1002/anie.202003078] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 04/07/2020] [Indexed: 01/19/2023]
Affiliation(s)
- Giorgio Olivo
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química Universitat de Girona Campus de Montilivi, C/ Pic de Peguera 15 17003 Girona Spain
| | - Giorgio Capocasa
- Dipartimento di Chimica and Istituto CNR per i Sistemi Biologici (ISB-CNR) Sezione Meccanismi di Reazione Sapienza Università di Roma P. le A. Moro 5 00185 Rome Italy
| | - Barbara Ticconi
- Dipartimento di Chimica and Istituto CNR per i Sistemi Biologici (ISB-CNR) Sezione Meccanismi di Reazione Sapienza Università di Roma P. le A. Moro 5 00185 Rome Italy
| | - Osvaldo Lanzalunga
- Dipartimento di Chimica and Istituto CNR per i Sistemi Biologici (ISB-CNR) Sezione Meccanismi di Reazione Sapienza Università di Roma P. le A. Moro 5 00185 Rome Italy
| | - Stefano Di Stefano
- Dipartimento di Chimica and Istituto CNR per i Sistemi Biologici (ISB-CNR) Sezione Meccanismi di Reazione Sapienza Università di Roma P. le A. Moro 5 00185 Rome Italy
| | - Miquel Costas
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química Universitat de Girona Campus de Montilivi, C/ Pic de Peguera 15 17003 Girona Spain
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3
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Parish EJ, Schroepfer GJ. Inhibitors of sterol synthesis. Synthesis of [2,4-3H]5α-cholest-8(14)-ene-3β,7α,15α-triol and [2,4-3H]5α-cholest-8(14)-en-38-ol-15-one. J Labelled Comp Radiopharm 2006. [DOI: 10.1002/jlcr.2580181006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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4
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Abstract
Oxygenated derivatives of cholesterol (oxysterols) present a remarkably diverse profile of biological activities, including effects on sphingolipid metabolism, platelet aggregation, apoptosis, and protein prenylation. The most notable oxysterol activities center around the regulation of cholesterol homeostasis, which appears to be controlled in part by a complex series of interactions of oxysterol ligands with various receptors, such as the oxysterol binding protein, the cellular nucleic acid binding protein, the sterol regulatory element binding protein, the LXR nuclear orphan receptors, and the low-density lipoprotein receptor. Identification of the endogenous oxysterol ligands and elucidation of their enzymatic origins are topics of active investigation. Except for 24, 25-epoxysterols, most oxysterols arise from cholesterol by autoxidation or by specific microsomal or mitochondrial oxidations, usually involving cytochrome P-450 species. Oxysterols are variously metabolized to esters, bile acids, steroid hormones, cholesterol, or other sterols through pathways that may differ according to the type of cell and mode of experimentation (in vitro, in vivo, cell culture). Reliable measurements of oxysterol levels and activities are hampered by low physiological concentrations (approximately 0.01-0.1 microM plasma) relative to cholesterol (approximately 5,000 microM) and by the susceptibility of cholesterol to autoxidation, which produces artifactual oxysterols that may also have potent activities. Reports describing the occurrence and levels of oxysterols in plasma, low-density lipoproteins, various tissues, and food products include many unrealistic data resulting from inattention to autoxidation and to limitations of the analytical methodology. Because of the widespread lack of appreciation for the technical difficulties involved in oxysterol research, a rigorous evaluation of the chromatographic and spectroscopic methods used in the isolation, characterization, and quantitation of oxysterols has been included. This review comprises a detailed and critical assessment of current knowledge regarding the formation, occurrence, metabolism, regulatory properties, and other activities of oxysterols in mammalian systems.
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Affiliation(s)
- G J Schroepfer
- Departments of Biochemistry, Rice University, Houston, Texas, USA.
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5
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Siddiqui AU, Wilson WK, Parish EJ, Gerst N, Pinkerton FD, Schroepfer GJ. Inhibitors of sterol synthesis. Synthesis and spectral properties of 3 beta-hydroxy-5 alpha-cholestan-15-one and its 17 beta-epimer and their effects on 3-hydroxy-3-methylglutaryl coenzyme A reductase activity. Chem Phys Lipids 1994; 74:1-15. [PMID: 7820900 DOI: 10.1016/0009-3084(94)90106-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
3 beta-Hydroxy-5 alpha-cholestan-15-one (2a) and its 14 beta-epimer 2b were prepared from 3 beta-acetoxy-5 alpha-cholest-8(14)-ene (3). Hydroboration of 3 at 45-50 degrees C gave a mixture of 5 alpha,14 alpha-cholestane-3 beta,15 alpha-diol and 5 alpha,14 beta-cholestane-3 beta,15 beta-diol, which were separated on silica gel as their 3 beta-tert-butyldimethylsilyl ethers 5a and 5b. Oxidation of 5a with pyridinium chlorochromate, followed by desilylation with tetrabutylammonium fluoride gave 2a. Analogous transformations of 5b gave 2b contaminated with 2a. Desilylation of 5b followed by oxidation with pyridinium chlorochromate resulted in a mixture composed mainly of 5 alpha,14 beta-cholestane-3,15-dione and 2b. Successive chromatographic separations on silica gel and reversed phase media gave 2b of high purity. Compound 2a was also prepared by lithium-ammonia reduction of 3 beta-hydroxy-5 alpha-cholest-8(14)-en-15-one (96% yield) and by selective reduction of 5 alpha-cholestane-3,15-dione with lithium tri-tert-butoxyaluminum hydride (90% yield). Isomers 2a and 2b were readily epimerized under acidic or basic conditions or under conditions used for gas chromatographic analysis. The purities of 2a and 2b were measured from nuclear magnetic resonance (NMR) spectra; chromatographic methods gave less reliable estimates of purity. NMR data also showed that ring C of the 14 beta sterols is predominantly in a chair conformation. The effects of 2a and 2b on the levels of 3-hydroxy-3-methylglutaryl coenzyme A reductase have been studied in Chinese hamster ovary cells.
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Affiliation(s)
- A U Siddiqui
- Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77251-1892
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6
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Siddiqui AU, Wilson WK, Ruecker KE, Pinkerton FD, Schroepfer GJ. Inhibitors of sterol synthesis. Chemical syntheses and spectral properties of 26-oxygenated derivatives of 3 beta-hydroxy-5 alpha-cholest-8(14)-en-15-one and their effects on 3-hydroxy-3-methylglutaryl coenzyme A reductase activity in CHO-K1 cells. Chem Phys Lipids 1992; 63:77-90. [PMID: 1486662 DOI: 10.1016/0009-3084(92)90025-k] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
26-Oxygenated derivatives of delta 8(14)-15-ketosterols have been synthesized from (25R)-3 beta,26-diacetoxy-5 alpha-cholest-8(14)-en-15-one (IX) as part of a program to prepare potential metabolites and analogs of 3 beta-hydroxy-5 alpha-cholest-8(14)-en-15-one (I), a potent regulator of cholesterol metabolism. Partial hydrolysis of IX gave a mixture, from which the 3 beta,26-diol II and the 26-acetate (XI) and 3 beta-acetate (X) monoesters were isolated. Mitsunobu reaction of XI followed by hydrolysis gave (25R)-3 alpha,26-dihydroxy-5 alpha-cholest-8(14)-en-15-one (VI). Oxidation of XI with pyridinium chlorochromate followed by hydrolysis of the acetate gave (25R)-26-hydroxy-5 alpha-cholest-8(14)-ene-3,15-dione (VII). Oxidation of X with Jones reagent followed by hydrolysis of the acetate gave (25R)-3 beta-hydroxy-15-keto-5 alpha-cholest-8(14)-en-26-oic acid (IVa). Jones oxidation of II gave (25R)-3,15-diketo-5 alpha-cholest-8(14)-en-26-oic acid (VII). 1H and 13C nuclear magnetic resonance assignments and analyses of mass spectral fragmentation data are presented for each of the new compounds and their derivatives. The 3,15-diketone VII was found to be highly active in lowering the levels of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity in CHO-K1 cells, with a potency comparable to that of I. In contrast, 3 alpha,26-diol VI was less potent than I or VII. The two carboxylic acid analogs IVa and VIII were considerably less potent than VI in lowering the levels of HMG-CoA reductase activity.
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Affiliation(s)
- A U Siddiqui
- Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77251-1892
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7
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Kim HS, Wilson WK, Kirkpatrick ND, Pinkerton FD, Swaminathan S, Hylarides MD, Schroepfer GJ. Inhibitors of sterol synthesis. Chemical synthesis of 7 alpha-ethyl and 16 alpha-ethyl derivatives of delta 8(14)-15-oxygenated sterols and their effects on 3-hydroxy-3-methylglutaryl coenzyme A reductase in CHO-K1 cells. Chem Phys Lipids 1992; 62:55-67. [PMID: 1423803 DOI: 10.1016/0009-3084(92)90054-s] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The enolate of 3 beta-hydroxy-5 alpha-cholest-8(14)-en-15-one (II), formed upon treatment of II with potassium tert-butoxide in tert-butanol, was alkylated with ethyl iodide. In addition to the major products, 3 beta-hydroxy-14 alpha-ethyl-5 alpha-cholest-7-en-15-one and its 3 beta-ethyl ether, small amounts of 3 beta-hydroxy-7 alpha-ethyl-5 alpha-cholest-8(14)-en-15-one (V), 3 beta-hydroxy-16 alpha-ethyl-5 alpha-cholest-8(14)-en-15-one (VI) and the 3 beta-ethyl ether of VI were isolated. When the enolate of II was formed by treatment with lithium diisopropylamide in tetrahydrofuran, the same alkylation furnished VI as the major product. Reduction of VI with lithium aluminum hydride gave 16 alpha-ethyl-5 alpha-cholest-8(14)-ene-3 beta, 15 alpha-diol (IX) and its 15 beta epimer X, which were separated by column chromatography. Full 1H and 13C nuclear magnetic resonance (NMR) assignments, augmented by nuclear Overhauser effect difference spectra for VI, established the stereochemistry of these diols at C-15 and C-16. The NMR results indicate that the 16 alpha-ethyl group affects the side-chain conformation. The effects of II, V, VI, IX and X on the levels of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity were studied in CHO-K1 cells. With the exception of IX, each of the compounds reduced the levels of HMG-CoA reductase activity. The order of potency with respect to suppression of the elevated levels of HMG-CoA reductase activity induced by transfer of the cells to lipid-deficient medium, was II greater than V greater than VI greater than X.
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Affiliation(s)
- H S Kim
- Department of Biochemistry and Cell Biology, Rice University, Houston, TX 77251-1892
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8
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Inhibitors of sterol synthesis. Characterization of trimethylsilyl dienol ethers of 3 beta-hydroxy-5 alpha-cholest-8(14)-en-15-one. Applications in the analysis of mitochondrial metabolites of the 15-ketosterol by gas chromatography-mass spectrometry. J Lipid Res 1991. [DOI: 10.1016/s0022-2275(20)41967-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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9
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Wilson WK, Wheeler ME, Pinkerton FD, St Pyrek J, Schroepfer GJ. Inhibitors of sterol synthesis. Characterization of beta,gamma-unsaturated analogs of 3 beta-hydroxy-5 alpha-cholest-8(14)-en-15-one and their effects on 3-hydroxy-3-methylglutaryl coenzyme A reductase activity in CHO-K1 cells. J Lipid Res 1991. [DOI: 10.1016/s0022-2275(20)41984-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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10
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Wilson WK, Pinkerton FD, Kirkpatrick ND, Schroepfer GJ. Inhibitors of sterol synthesis. Chemical synthesis of 5 beta-cholest-8-ene-3 beta,15 alpha-diol and its effects on 3-hydroxy-3-methylglutaryl coenzyme A reductase activity in CHO-K1 cells. J Lipid Res 1989. [DOI: 10.1016/s0022-2275(20)38318-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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11
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Saucier SE, Kandutsch AA, Gayen AK, Swahn DK, Spencer TA. Oxysterol Regulators of 3-Hydroxy-3-methylglutaryl-CoA Reductase in Liver. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)83510-4] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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12
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Stephens TW, Schroepfer GJ. Inhibitors of sterol synthesis. 15-oxygenated steryl ester hydrolase activity of rat liver at neutral and acid pH. BIOCHIMICA ET BIOPHYSICA ACTA 1989; 1001:127-33. [PMID: 2917137 DOI: 10.1016/0005-2760(89)90138-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
5 alpha-Cholest-8(14)-en-3 beta-ol-15-one (15 ketosterol) is a potent inhibitor of cholesterol biosynthesis with significant hypocholesterolemic activity. The results of a recent study (Schroepfer, G.J., Jr., Christophe, A., Chu, A.J., Izumi, A., Kisic, A. and Sherrill, B.C. (1988) Chem. Phys. Lipids 48, 29-58) have indicated that, after intragastric administration of the 15-ketosterol in triolein to rats, most of the compound in intestinal lymph occurs in the form of the oleate ester, which is associated with chylomicrons. Moreover, after intravenous administration of chylomicrons containing the oleate ester of 15-[2,4-3H]ketosterol, rapid and selective uptake of 3H by liver was observed, which was associated with the rapid and substantial appearance of labeled free 15-ketosterol in liver. The present study concerns the capabilities of rat liver fractions to catalyze the hydrolysis of 15-ketosteryl oleate. Efficient hydrolysis was observed at acid pH with a digitonin-solubilized extract of rat liver, with a rate similar to that for the hydrolysis of cholesteryl oleate. The distribution of acid 15-ketosteryl oleate hydrolase of whole liver homogenate on a metrizamide isopycnic density gradient was similar to that of acid cholesteryl oleate hydrolase and acid phosphatase, suggesting that the lysosomal acid lipase is the enzyme responsible for the hydrolysis of the 15-ketosteryl oleate at acid pH. At neutral pH, 15-ketosteryl oleate and cholesteryl oleate was hydrolyzed at similar rates by the microsomal fraction of liver homogenate, whereas the 15-ketosteryl oleate was hydrolyzed at a much lower rate than cholesteryl oleate by the cytosolic fraction. The distribution of neutral 15-ketosteryl oleate hydrolase activity of whole liver homogenate on a metrizamide isopycnic density gradient was most correlated to a microsomal esterase, whereas cholesteryl oleate hydrolase activity was most correlated to a cytosolic enzyme. Both 15-ketosteryl oleate and cholesteryl oleate hydrolase activities were correlated to a mitochondrial marker enzyme.
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Affiliation(s)
- T W Stephens
- Department of Biochemistry, Rice University, Houston, TX 77251
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13
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Parish EJ, Tsuda M, Schroepfer GJ. Stereospecific 1,4-addition to an alpha,beta-unsaturated steroidal epoxide: syntheses of new 15-oxygenated sterols. Chem Phys Lipids 1988; 49:119-29. [PMID: 3233707 DOI: 10.1016/0009-3084(88)90073-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
3 beta-Benzoyloxy-14 alpha,15 alpha-epoxy-5 alpha-cholest-7-ene (1) is a key intermediate in the synthesis of C-7 and C-15 oxygenated sterols. Treatment of 1 with benzoyl chloride resulted in the formation of 3 beta,15 alpha-bis-benzoyloxy-7 alpha-chloro-5 alpha-cholest-8(14)-ene (2). Reaction of 2 with LiAlH4 or LiAlD4 resulted in the formation of 5 alpha-cholest-7-ene-3 beta,15 alpha-diol (3a) or [14 alpha-2H]5 alpha-cholest-7-ene-3 beta,15 alpha-diol (3b). Diol 3b was selectively oxidized by Ag2CO3/celite to [14 alpha-2H]5 alpha-cholest-7-en-15 alpha-ol-3-one (4). Treatment of 1 with MeMgI/CuI gave 7 alpha-methyl-5 alpha-cholest-8(14)-ene-3 beta,15 alpha-diol (5). Selective oxidation of 5 with pyridinium chlorochromate (PCC)/pyridine or oxidation with PCC resulted in the formation of 7 alpha-methyl-5 alpha-cholest-8(14)-en-3 beta-ol-15-one (6) and 7 alpha-methyl-5 alpha-cholest-8(14)-ene-3,15-dione, respectively. Reduction of 6 with LiAlH4 yielded 5 and 7 alpha-methyl-5 alpha-cholest-8(14)-ene-3 beta,15 beta-diol (6). Reaction of 1 with benzoic acid/pyridine gave 3 beta,7 alpha-bis-benzoyloxy-5 alpha-cholest-8(14)-en-15 alpha-ol (9). Treatment of 9 with LiAlH4 or ethanolic KOH resulted in the formation of 5 alpha-cholest-8(14)-ene-3 beta,7 alpha,15 alpha-triol (10). Dibenzoate 9, upon brief treatment with mineral acid, gave 3 beta-benzoyloxy-5 alpha-cholest-8(14)-ene-15-one (11). Oxidation of 9 with PCC yielded 3 beta,7 alpha-bis-benzoyloxy-5 alpha-cholest-8(14)-ene-15-one (12). Ketone 12 was also prepared by the selective hydride reduction of 5 alpha-cholest-8(14)-en-7 alpha-ol-3,15-dione (13) to give 5 alpha-cholest-8(14)-ene-3 beta,7 alpha-diol-15-one (14), which was then treated with benzoyl chloride to produce 12.
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Affiliation(s)
- E J Parish
- Department of Biochemistry, Rice University, Houston, TX 77001
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14
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Pajewski TN, Pinkerton FD, Miller LR, Schroepfer GJ. Inhibitors of sterol synthesis. Studies of the metabolism of 5 alpha-cholest-8(14)-en-3 beta-ol-15-one in Chinese hamster ovary cells and its effects on activities of early enzymes in cholesterol biosynthesis. Chem Phys Lipids 1988; 48:153-68. [PMID: 2907421 DOI: 10.1016/0009-3084(88)90086-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The metabolism of [2,4-3H]5 alpha-cholest-8(14)-en-3 beta-ol-15-one (I) has been studied in Chinese hamster ovary (CHO-K1) cells which were maintained in a lipid-deficient medium. The incorporation of I into the cells was linear with respect to sterol concentration in the medium over the ranges of concentrations studied and was more than 3.5 times that of the uptake of cholesterol. The results of detailed chromatographic analyses of the lipids recovered from the cells after 6 h of incubation with [2,4-3H]I (0.5 microM or 6.0 microM) indicated that most of the 3H was associated with free I. Considerably lesser amounts of the 3H was associated with esters of I. No formation of [3H]cholesterol or [3H]cholesteryl esters (or other C27 monohydroxysterols) from labeled I was observed. The labeled material with the chromatographic behavior of the esters of I gave, after mild alkaline hydrolysis, the free 15-ketosterol which was characterized by the results of chromatographic and cocrystallization studies. Upon transfer of the CHO-K1 cells from a culture medium containing 8% newborn calf serum to the same medium containing 8% lipid-deficient newborn calf serum, increases in the levels of activity of cytosolic acetoacetyl-CoA thiolase and 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthase and of HMG-CoA reductase were observed. These increases were blocked by the addition of I at a concentration of 1.0 microM. I (1.0 microM) also caused a decrease in the levels of activity of the three enzymes in cells previously grown in medium containing lipid-deficient serum. These results demonstrate that I not only affects the enzymatic reduction of HMG-CoA but also the enzymatic formation of this key intermediate in cholesterol biosynthesis.
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Affiliation(s)
- T N Pajewski
- Department of Biochemistry and Chemistry, Rice University, Houston, TX 77251
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15
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Schroepfer GJ, Parish EJ, Tsuda M, Kandutsch AA. Inhibitors of sterol synthesis. Chemical syntheses, properties and effects of 4,4-dimethyl-15-oxygenated sterols on sterol synthesis and on 3-hydroxy-3-methylglutaryl coenzyme A reductase activity in cultured mammalian cells. Chem Phys Lipids 1988; 47:187-207. [PMID: 3168085 DOI: 10.1016/0009-3084(88)90012-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The chemical syntheses of a number of 4,4-dimethyl substituted 15-oxygenated sterols have been pursued to permit evaluation of their activity in the inhibition of the biosynthesis of cholesterol and other biological effects. Described herein are the first chemical syntheses of 4,4-dimethyl-14 alpha-ethyl-5 alpha-cholest-7-en-3 beta-ol-15-one, 3 beta,15 alpha-diacetoxy-4,4-dimethyl-14 alpha-ethyl-5 alpha-cholest-7-ene, 3 beta-acetoxy-4,4-dimethyl-14 alpha-ethyl-5 alpha-cholest-7-en-15 beta-ol, 4,4-dimethyl-14 alpha-ethyl-5 alpha-cholest-7-ene-3 beta,15 alpha-diol, 4,4-dimethyl-14 alpha-ethyl-5 alpha-cholest-7-ene-3 beta,15 beta-diol, 4,4-dimethyl-14 alpha-ethyl-5 alpha-cholest-7-en-15 alpha-ol-3-one, 3 beta-benzoyloxy-4,4-dimethyl-5 alpha-cholest-8(14)-ene-7 alpha,15 alpha-diol, 7 alpha,15 alpha-diacetoxy-3 beta-benzoyloxy-4,4-dimethyl-5 alpha-cholest-8(14)-ene, 4,4-dimethyl-5 alpha-cholest-8(14)-en-3 beta-ol-15-one and 3 beta,7 alpha,15 alpha-tri-o-bromobenzoyloxy-5 alpha-cholest-8(14)-ene. Also prepared for use in the biological experiments were 4,4-dimethyl-5 alpha-cholest-7-ene-3 beta,15 alpha-diol, 4,4-dimethyl-5 alpha-cholest-8-ene-3 beta,15 alpha-diol and 4,4-dimethyl-5 alpha-cholest-8(14)-ene-3 beta,7 alpha,15 alpha-triol. The effects of twelve 4,4-dimethyl substituted 15-oxygenated sterols and of four 4,4-dimethyl substituted 32-oxygenated sterols on sterol synthesis and on the level of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity were evaluated in mouse L cells. With the exception of 4,4-dimethyl-5 alpha-cholest-8(14)-ene-3 beta,7 alpha,15 alpha-triol, all of the 4,4-dimethyl substituted 15-oxygenated sterols caused a 50% inhibition of sterol synthesis at less than 10(-6) M and six of the 4,4-dimethyl substituted 15-oxygenated sterols caused a 50% inhibition of sterol synthesis at less than 10(-7) M. 4,4-Dimethyl-14 alpha-ethyl-5 alpha-cholest-7-ene-3 beta,15 alpha-diol caused a 50% decrease in sterol synthesis at 10(-8) M. The potencies of the 4,4-dimethyl substituted 15-oxygenated and C-32-oxygenated sterols with respect to inhibition of sterol synthesis and suppression of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity have been compared with those of the corresponding sterols lacking the 4,4-dimethyl substitution.
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Affiliation(s)
- G J Schroepfer
- Department of Biochemistry, Rice University, Houston, TX 77251
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16
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Hietter H, Gouyette A, Van Dorsselaer A, Luu B. Metabolism of cytotoxic hydroxysterols in cultured cells. Chemical characterization of metabolites. JOURNAL OF STEROID BIOCHEMISTRY 1988; 29:481-9. [PMID: 3379957 DOI: 10.1016/0022-4731(88)90182-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The metabolism of labelled 7 alpha- and 7 beta-hydroxycholesterol was investigated in two lymphoma cell lines (YAC-1, RDM-4), in murine splenocytes and in HTC hepatoma cells. The structures of the metabolites in lymphoma cells were determined as 3 beta-esters of C14-C20 fatty acids by nuclear magnetic resonance and mass spectrometric studies. In hepatoma cells, more polar metabolites of 7 alpha- and 7 beta-hydroxycholesterol were detected whereas, in non-dividing lymphocyte cells, no metabolic transformation occurs. Therefore, metabolic transformation of the hydroxycholesterol is not required for the expression of their activity and the question of the physiological role of the metabolic products is raised.
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Affiliation(s)
- H Hietter
- Laboratoire de Chimie Organique des Substances Naturelles associé au CNRS, Centre de Neurochimie, Strasbourg, France
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17
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Bowen ST, Parish EJ, Wilson WK, Schroepfer GJ, Quiocho FA. Inhibitors of sterol synthesis. Concerning the structure of 15 beta-methyl-5 alpha,14 beta-cholest-7-ene-3 beta,15 alpha-diol, an inhibitor of cholesterol biosynthesis. Chem Phys Lipids 1988; 46:245-51. [PMID: 3365828 DOI: 10.1016/0009-3084(88)90038-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The chemical synthesis of 3 beta-p-bromobenzoyloxy-15 beta-methyl-5 alpha,14 beta-cholest-7-en-15 alpha-ol from 15 beta-methyl-5 alpha, 14 beta-cholest-7-ene-3 beta,15 alpha-diol is described. The structure of the former compound was unambiguously determined by X-ray crystallographic analysis. The space group of the crystal was P2 with unit cell parameters a = 12.611 A, b = 9.826 A, c = 13.221 A, b = 91.71 degrees and Z = 2. The structure was solved by the heavy atom method and refined to a final R of 0.041. Asymmetry parameters indicated that ring A is a symmetrical chair, that rings B and C are half chairs, and that ring D is a 15 alpha-envelope.
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Affiliation(s)
- S T Bowen
- Department of Biochemistry, Rice University, Houston, TX 77251
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18
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Schroepfer GJ, Parish EJ, Kandutsch AA. Inhibitors of sterol biosynthesis. Synthesis and activities of ring C oxygenated sterols. Chem Phys Lipids 1988; 46:147-54. [PMID: 3342458 DOI: 10.1016/0009-3084(88)90125-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The chemical syntheses of a number of C27 ring C oxygenated sterols have been pursued to permit evaluation of their activity in the inhibition of sterol biosynthesis in cultured mammalian cells. Thus, 5 alpha-cholest-7-ene-3 beta, 11 alpha-diol, 3 alpha-hydroxy-5 alpha-cholest-9(11)-en-12-one, and the previously unreported 11 alpha-hydroxy-5 alpha-cholest-7-en-3-one, 5 alpha-cholest-9(11)-ene-3,12-dione, and 3 beta-hydroxy-5 alpha-cholest-9 (11)-en-12-one have been synthesized. The effects of these compounds on the synthesis of digitonin-precipitable sterols from labeled acetate in mouse L cells and on the levels of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity in the same cells have been investigated and compared with previously published data on other ring C oxygenated sterols. 5 alpha-Cholest-7-ene-3 beta, 11 alpha-diol was shown to be the most potent inhibitor of sterol synthesis.
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Affiliation(s)
- G J Schroepfer
- Department of Biochemistry, Rice University, Houston, TX 77251
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St Pyrek J, Schroepfer GJ. Inhibitors of sterol synthesis. Synthesis and spectral characterization of fatty acids esters of 5 alpha-cholest-8(14)-en-3 beta-ol-15-one. J Lipid Res 1987. [DOI: 10.1016/s0022-2275(20)38595-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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20
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Inhibitors of sterol synthesis. Spectral characterization of derivatives of 5 alpha-cholest-8(14)-en-3 beta-ol-15-one. J Lipid Res 1987. [DOI: 10.1016/s0022-2275(20)38594-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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21
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Taylor FR, Saucier SE, Shown EP, Parish EJ, Kandutsch AA. Correlation between oxysterol binding to a cytosolic binding protein and potency in the repression of hydroxymethylglutaryl coenzyme A reductase. J Biol Chem 1984. [DOI: 10.1016/s0021-9258(18)90757-x] [Citation(s) in RCA: 247] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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22
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15-Hydroxylation of 5 beta-cholestan-3 alpha-ol and 24 alpha-ethyl-5 beta-cholestan-3 alpha-ol in rat liver supernatants (18,000 X g). J Biol Chem 1982. [DOI: 10.1016/s0021-9258(18)33507-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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23
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Schroepfer GJ, Parish EJ, Kisic A, Jackson EM, Farley CM, Mott GE. 5 alpha-Cholest-8(14)-en-3 beta-ol-15-one, a potent inhibitor of sterol biosynthesis, lowers serum cholesterol and alters distributions of cholesterol in lipoproteins in baboons. Proc Natl Acad Sci U S A 1982; 79:3042-6. [PMID: 6953447 PMCID: PMC346345 DOI: 10.1073/pnas.79.9.3042] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
5 alpha-Cholest-8(14)-en-3 beta-0l-15-one has been found to have significant hypocholesterolemic action on oral administration to baboons at dosages of 50 and 75 mg/kg of body weight. The 15-ketosterol decreased the levels of total serum cholesterol and low density lipoprotein plus very low density lipoprotein (LDL/VLDL) cholesterol and the percentage of total cholesterol associated with LDL/VLDL and increased the percentage of total cholesterol associated with high density lipoprotein (HDL). Moreover, administration of the steroid was associated with an absolute increase in the concentration of HDL cholesterol in those animals with low HDL levels (or with a low percentage of total serum cholesterol in the HDL fraction.
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Miller LR, Pajewski TN, Schroepfer GJ. Inhibitors of sterol synthesis. Studies of in vitro effects of C27 15-oxygenated sterols on sterol synthesis in cell free homogenates of rat liver. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(18)34939-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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25
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14 alpha-Ethyl-5 alpha-cholest-7-ene-3 beta,15 alpha-diol, a potent inhibitor of sterol biosynthesis, has two sites of action in cultured mammalian cells. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(19)68128-7] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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26
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Inhibitors of sterol synthesis. Chemical syntheses and activities of new derivatives of 15-oxygenated sterols. Chem Phys Lipids 1981. [DOI: 10.1016/0009-3084(81)90051-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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27
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Miller L, Pascal R, Schroepfer G. Inhibitors of sterol synthesis. Differential effects of 14 alpha-hydroxymethyl-5 alpha-cholest-7-ene-3 beta, 15 alpha-diol and 14 alpha-hydroxymethyl-5 alpha-cholest-6-ene-3 beta, 15 alpha-diol on sterol synthesis in cell-free homogenates of rat liver. J Biol Chem 1981. [DOI: 10.1016/s0021-9258(18)43392-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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28
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Rip J, Rupar C, Chaudhary N, Carroll K. Localization of a dolichyl phosphate phosphatase in plasma membranes of rat liver. J Biol Chem 1981. [DOI: 10.1016/s0021-9258(19)69896-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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29
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Monger D, Parish E, Schroepfer G. 15-Oxygenated sterols. Enzymatic conversion of [2,4]3H]5 alpha-cholest-8(14)-en-3 beta-ol-15-one to cholesterol in rat liver homogenate preparations. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(19)70264-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Schroepfer GJ, Parish EJ, Pascal RA, Kandutsch AA. Inhibition of sterol biosynthesis in animal cells by 14 alpha-hydroxymethyl sterols. J Lipid Res 1980. [DOI: 10.1016/s0022-2275(20)42227-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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32
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Pascal R, Schroepfer G. 15-Oxygenated sterols with the unnatural cis-C-D ring junction. Studies of the metabolism of 5 alpha,14 beta-cholest-7-ene-3 beta,15 alpha-diol and 5 alpha,14 beta-cholest-7-ene-3 beta,15 beta-diol. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(19)85738-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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33
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Newcomer ME, Gilliland GL, Parish EJ, Schroepfer GJ, Quiocho FA. Concerning the structure of 7 alpha,15 beta-dichloro-5 alpha-cholest-8(14)-en-3 beta-ol, a novel inhibitor of cholesterol biosynthesis. Chem Phys Lipids 1980; 26:249-58. [PMID: 7371118 DOI: 10.1016/0009-3084(80)90055-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Treatment of 3 beta-p-bromobenzoyloxy-14 alpha,15 alpha-epoxy-5 alpha-cholest-7-ene with gaseous HCl in chloroform at -25 degrees C gave 3 beta-p-bromobenzoyloxy-7 alpha,15 beta-dichloro-5 alpha-cholest-8(14)-ene in 93% yield. The structure of the latter compound was unequivocally established by the results of X-ray crystallographic analysis.
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Parish EJ, Schroepfer GJ. Stereoselectivity of raney nickel catalyst in hydrogenolysis of a steroidal α,β-unsaturated epoxide. Chemical synthesis of 3β-benzoyloxy-5α-cholest-8(14)-en-15α-ol. Chem Phys Lipids 1980. [DOI: 10.1016/0009-3084(80)90003-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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