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Guo LW, Wilson WK, Pang J, Shackleton CHL. Chemical synthesis of 7- and 8-dehydro derivatives of pregnane-3,17alpha,20-triols, potential steroid metabolites in Smith-Lemli-Opitz syndrome. Steroids 2003; 68:31-42. [PMID: 12475721 DOI: 10.1016/s0039-128x(02)00113-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Pregnane-3,17 alpha,20-triols bearing unsaturation at delta(7), delta(8), delta(5,7), or delta(5,8) have been tentatively identified as steroid metabolites in Smith-Lemli-Opitz syndrome (SLOS). Starting with 17 alpha-hydroxypregnenolone diacetate, we have synthesized 13 unsaturated C(21) triols by four different routes in one to four steps. These multifunctional steroids were prepared by a series of regio- and stereoselective transformations chosen to minimize facile olefin isomerization and 17-deoxygenation. The results include a study of stereoselectivity in the reduction of 17 alpha-hydroxy-20-ketosteroids, an alternative method for reducing diethyl azodicarboxylate adducts of delta(5,7) steroids, and an efficient oxidation-isomerization of a delta(5,7) steroid using cholesterol oxidase. The 13 triols and their synthetic precursors were fully characterized by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. The NMR data, together with molecular modeling, indicated unanticipated conformational heterogeneity for two synthetic intermediates, 17 alpha-hydroxypregna-4,7-diene-3,20-dione and 17 alpha-hydroxy-5 beta-pregn-7-ene-3,20-dione. The unsaturated C(21) triols are useful as reference standards to study adrenal steroid production in SLOS and to develop methods for pre- and postnatal diagnosis of this congenital disorder.
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Affiliation(s)
- Li-Wei Guo
- Department of Biochemistry and Cell Biology, Rice University, 6100 Main Street, Houston, TX 77005-1892, USA
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2
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Xiong Q, Ruan B, Whitby FG, Tuohy RP, Belanger TL, Kelley RI, Wilson WK, Schroepfer GJ. A colorimetric assay for 7-dehydrocholesterol with potential application to screening for Smith-Lemli-Opitz syndrome. Chem Phys Lipids 2002; 115:1-15. [PMID: 12047895 DOI: 10.1016/s0009-3084(01)00205-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Smith-Lemli-Opitz syndrome (SLOS; MIM 270400) is a genetic disorder characterized by hypocholesterolemia and elevated 7-dehydrocholesterol (7DHC) levels resulting from mutations affecting 7-dehydrocholesterol reductase. We describe a colorimetric assay for 7DHC with potential application to large-scale screening for SLOS. Reaction of 7DHC and its esters with the Liebermann-Burchard reagent resulted in a brief initial absorbance at 510 nm (pink color) followed by an absorbance at 620 nm (blue color) after 2 min, while cholesterol samples were essentially colorless. The assay could identify typical SLOS blood samples by their pink color and increased absorbance at 620 nm after 2 min. Colorimetric identification of mild SLOS cases requires monitoring of the transient absorbance at 510 nm, which must be detected immediately after rapid, consistent mixing of the reagents. The need for special mixing devices and rigorous validation precludes sporadic use of the assay for diagnosing suspected SLOS cases. We also studied the stability of 7DHC in dried SLOS blood spots on Guthrie cards, which are widely used for archiving neonatal blood. Decomposition of 7DHC was effectively retarded by storage at low temperature and by precoating of the cards with antioxidants. The combined results provide a foundation for development of a simple, automated test for SLOS screening.
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Affiliation(s)
- Quanbo Xiong
- Department of Biochemistry and Cell Biology, Rice University, MS140, 6100 Main Street, Houston, TX 77005-1892, USA
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3
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Aberrant pathways in the late stages of cholesterol biosynthesis in the rat: origin and metabolic fate of unsaturated sterols relevant to the Smith-Lemli-Opitz syndrome. J Lipid Res 2000. [DOI: 10.1016/s0022-2275(20)31970-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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4
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Ruan B, Gerst N, Emmons GT, Shey J, Schroepfer GJ. Sterol synthesis. A timely look at the capabilities of conventional and silver ion high performance liquid chromatography for the separation of C27 sterols related to cholesterol biosynthesis. J Lipid Res 1997. [DOI: 10.1016/s0022-2275(20)30045-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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5
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Moebius FF, Bermoser K, Reiter RJ, Hanner M, Glossmann H. Yeast sterol C8-C7 isomerase: identification and characterization of a high-affinity binding site for enzyme inhibitors. Biochemistry 1996; 35:16871-8. [PMID: 8988026 DOI: 10.1021/bi961996m] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The yeast gene ERG2 encodes a sterol C8-C7 isomerase and is essential for ergosterol synthesis and cell proliferation. Its striking homology with the so-called sigma1 receptor of guinea pig brain, a polyvalent steroid and drug binding protein, suggested that the yeast sterol C8-C7 isomerase (ERG2) carries a similar high affinity drug binding domain. Indeed the sigma ligands [3H]haloperidol (Kd = 0.3 nM) and [3H]ifenprodil (Kd = 1.4 nM) bound to a single population of sites in ERG2 wild type yeast microsomes (Bmax values of 77 and 61 pmol/mg of protein, respectively), whereas binding activity was absent in strains carrying ERG2 gene mutations or disruptions. [3H]Ifenprodil binding was inhibited by sterol isomerase inhibitors such as fenpropimorph (Ki = 0.05 nM), tridemorph (Ki = 0.09 nM), MDL28,815 (Ki = 0.44 nM), triparanol (Ki = 1.5 nM), and AY-9944 (Ki = 5.8 nM). [3H]Haloperidol specifically photoaffinity-labeled a protein with an apparent molecular weight of 27400, in agreement with the molecular mass of the sterol C8-C7 isomerase (24900 Da). 9E10 c-myc antibodies specifically immunoprecipitated the c-myc tagged protein after [3H]haloperidol photolabeling, unequivocally proving that the drug binding site is localized on the ERG2 gene product. Haloperidol, trifluperidol, and ifenprodil inhibited the growth of Saccharomyces cerevisiae and reduced the ergosterol content of cells grown in their presence. Our results demonstrate that the yeast sterol C8-C7 isomerase has a polyvalent high-affinity drug binding site similar to mammalian sigma receptors and that in yeast sigma ligands inhibit sterol biosynthesis.
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Affiliation(s)
- F F Moebius
- Institut für Biochemische Pharmakologie, Universität Innsbruck, Austria
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6
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Wilson WK, Sumpter RM, Warren JJ, Rogers PS, Ruan B, Schroepfer GJ. Analysis of unsaturated C27 sterols by nuclear magnetic resonance spectroscopy. J Lipid Res 1996. [DOI: 10.1016/s0022-2275(20)39137-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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7
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Izumi A, Pinkerton F, Nelson S, Pyrek J, Neill P, Smith JH, Schroepfer G. Inhibitors of sterol synthesis. Submicromolar 14 alpha-ethyl-5 alpha-cholest-7-ene-3 beta, 15 alpha-diol causes a major modification of the sterol composition of CHO-K1 cells and a marked change in cell morphology. J Lipid Res 1994. [DOI: 10.1016/s0022-2275(20)39968-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
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8
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Inhibitors of sterol synthesis. A highly efficient and specific side-chain oxidation of 3 beta-acetoxy-5 alpha-cholest-8(14)-en-15-one for construction of metabolites and analogs of the 15-ketosterol. J Lipid Res 1992. [DOI: 10.1016/s0022-2275(20)41623-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [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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Taton M, Benveniste P, Rahier A. Microsomal delta 8,14-sterol delta 14-reductase in higher plants. Characterization and inhibition by analogues of a presumptive carbocationic intermediate of the reduction reaction. EUROPEAN JOURNAL OF BIOCHEMISTRY 1989; 185:605-14. [PMID: 2591378 DOI: 10.1111/j.1432-1033.1989.tb15156.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
An enzymatic assay for delta 8,14-sterol delta 14-reductase, an enzyme involved in sterol biosynthesis, has been developed for the first time in higher plants. The properties of the microsomal enzyme have been established with respect to cofactor requirements, kinetics and substrate specificity. This enzymatic double-bound reduction is thought to proceed through an electrophilic addition mechanism, involving a C14 putative carbonium ion high-energy intermediate. Using this in vitro assay, ammonium and iminium analogues of this cationic intermediate were shown to be potent inhibitors of the reduction reaction. Thus, compounds of the N-alkyl-8-aza-4 alpha,10-dimethyl-trans-decal-3 beta-ol series strongly inhibited sterol reductase (I50 = 0.07 - 4 microM) (I50/Km = 10(-4) - 10(-3), as did the antimycotic agent 15-azasterol (I50 = 0.03 microM); all of these compounds act as reaction-intermediate analogues of the proposed C14 carbonium ion intermediate. Moreover, the in vitro inhibition of the plant sterol reductase by a series of ammonium-ion-containing fungicides was demonstrated. The relative specificity of these different series of inhibitors toward cycloeucalenol-obtusifoliol isomerase, delta 8----delta 7-sterol isomerase and delta 8,14-sterol delta 14-reductase, was directly studied.
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Affiliation(s)
- M Taton
- Institut de Botanique, Unité Associée 1182 du Centre National de la Recherche Scientifique, Strasbourg, France
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10
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Kudo K, Emmons GT, Casserly EW, Via DP, Smith LC, St Pyrek J, Schroepfer GJ. Inhibitors of sterol synthesis. Chromatography of acetate derivatives of oxygenated sterols. J Lipid Res 1989. [DOI: 10.1016/s0022-2275(20)38296-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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11
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Pajewski TN, Brabson JS, Kisic A, Wang KS, Hylarides MD, Jackson EM, Schroepfer GJ. Inhibitors of sterol synthesis. Metabolism of [2,4-3H]5 alpha-cholest-8(14)-en-3 beta-ol-15-one after oral administration to a nonhuman primate. Chem Phys Lipids 1989; 49:243-63. [PMID: 2720860 DOI: 10.1016/0009-3084(89)90072-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
5 alpha-Cholest-8(14)-en-3 beta-ol-15-one is a potent inhibitor of cholesterol biosynthesis which has significant hypocholesterolemic activity upon oral administration to rodents and nonhuman primates. In the present study the metabolism of the 15-ketosterol has been investigated after the oral administration of a mixture of [2,4-3H]5 alpha-cholest-8(14)-en-3 beta-ol-15-one and [4-14C]cholesterol to 8 baboons. Blood samples were obtained at 4, 8, 12, 16, and 24 h after administration of the labeled sterols. Clear differences in the time courses of the levels of 3H and 14C in plasma were observed. 3H in plasma showed maximum values at 4 to 8 h, whereas maximum values for the levels of 14C were observed much later. 3H in plasma was shown to be primarily in the form of its metabolites, i.e. esters of the 15-ketosterol, cholesterol, and cholesteryl esters. The levels of the 15-ketosterol and of each of these metabolites showed different changes with time. The labeled cholesterol (and the cholesterol moiety of the cholesteryl esters), formed from the [2,4-3H]-15-ketosterol, was characterized by chromatography and by purification by way of its dibromide derivative. At 24 h after the administration of the labeled sterols, the distribution of 3H in plasma lipoprotein fractions paralleled that of 14C, with most of the 3H and 14C in high density lipoprotiens (HDL) and low density lipoproteins (LDL). Almost all of the 3H in HDL and in LDL was found as cholesterol, cholesteryl esters and esters of the 15-ketosterol. The distribution of 3H in HDL and in LDL of the free 15-ketosterol, esters of the 15-ketosterol, cholesterol, and cholesteryl esters was similar to that of plasma, thereby indicating no unusual concentration of any of the 3H labeled components in HDL or LDL.
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Affiliation(s)
- T N Pajewski
- Department of Biochemistry, Rice University, Houston, TX 77251
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12
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Kim HS, Wilson WK, Needleman DH, Pinkerton FD, Wilson DK, Quiocho FA, Schroepfer GJ. Inhibitors of sterol synthesis. Chemical synthesis, structure, and biological activities of (25R)-3 beta,26-dihydroxy-5 alpha-cholest-8(14)-en-15-one, a metabolite of 3 beta-hydroxy-5 alpha-cholest-8(14)-en-15-one. J Lipid Res 1989. [DOI: 10.1016/s0022-2275(20)38385-1] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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13
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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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14
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Brabson JS, Schroepfer GJ. Inhibitors of sterol synthesis. Studies of the distribution and metabolism of 5 alpha-[2,4-3H]cholest-8(14)-en-3 beta-ol-15-one after intragastric administration to rats. Steroids 1988; 52:51-68. [PMID: 3247671 DOI: 10.1016/0039-128x(88)90217-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
5 alpha-[2,4-3H]Cholest-8(14)-en-3 beta-ol-15-one was administered to a series of male Sprague-Dawley rats by intragastric intubation in the form of an emulsion in a mixture of triolein, sodium taurocholate, bovine serum albumin, and glucose. [4-14C]Cholesterol was similarly administered to a second series of rats. The distribution of 3H and 14C was studied at 12 and 48 h after the administration of the sterols. The results demonstrated that the 15-ketosterol is absorbed and metabolized to material with the chromatographic properties of fatty acid esters of the 15-ketosterol, to cholesterol, and to fatty acid esters of cholesterol. The [3H]cholesterol formed from the 15-ketosterol was characterized by its behavior on silicic acid-Super Cel column chromatography, by the chromatographic behavior of its acetate derivative on alumina-AgNO3 column chromatography, and by purification by way of its dibromide derivative without significant change in specific activity. The general distribution of 3H was similar to that of 14C. No unusual concentration of 3H in any of the organs studied was observed.
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Affiliation(s)
- J S Brabson
- Department of Biochemistry, Rice University, Houston, TX 77251
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15
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Monger DJ, Schroepfer GJ. Inhibitors of cholesterol biosynthesis. Further studies of the metabolism of 5 alpha-cholest-8(14)-en-3 beta-ol-15-one in rat liver preparations. Chem Phys Lipids 1988; 47:21-46. [PMID: 3396133 DOI: 10.1016/0009-3084(88)90030-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
5 alpha-Cholest-8(14)-en-3 beta-ol-15-one is a potent inhibitor of sterol biosynthesis in mammalian cells in culture and has significant hypocholesterolemic activity upon oral administration to rodents and non-human primates. The conversion of the 15-ketosterol to cholesterol upon incubation with the 10,000 x g supernatant fraction of rat liver homogenate preparations under aerobic conditions has been reported (D.J. Monger, E.J. Parish and G.J. Schroepfer, Jr. (1980) J. Biol. Chem. 255, 11122-11129). Presented herein are results of studies of the metabolism of [2,4-3H]5 alpha-cholest-8(14)-en-3 beta-ol-15-one obtained upon incubation with the microsomal, cytosolic and the 10,000 x g supernatant fractions of liver homogenates of female rats under a variety of conditions. The results of these studies indicated metabolism of the 15-ketosterol to materials with the chromatographic properties of fatty acid esters of the 15-ketosterol, fatty acid esters of C27-monohydroxysterols, a component similar to the 15-ketosterol (possibly an isomer of the delta 8(14)-15-ketosterol), and a polar component. Detailed studies of the C27-monohydroxysterols obtained from incubation of the 15-ketosterol under anaerobic conditions indicated the formation of labeled 5 alpha-cholesta-8,14-dien-3 beta-ol and 5 alpha-cholest-7-en-3 beta-ol which were characterized by their behavior on silicic acid column chromatography, by the behavior of their acetate derivatives on medium pressure liquid chromatography on alumina-AgNO3 columns, and by co-crystallization of the labeled sterols with authentic unlabeled standards. The identification of 5 alpha-cholesta-8,14-dien-3 beta-ol and 5 alpha-cholest-7-en-3 beta-ol as metabolites of the 15-ketesterol, coupled with previous studies of the metabolism of 5 alpha-cholesta-8,14-dien-3 beta-ol and of 5 alpha-cholest-8(14)-ene-3 beta, 15 alpha-diol and 5 alpha-cholest-8(14)-ene-3 beta, 15 beta-diol has permitted the formulation of a scheme for the overall metabolism of the 15-ketosterol to cholesterol.
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Affiliation(s)
- D J Monger
- Department of Biochemistry, Rice University, Houston, TX 77251
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16
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Schroepfer GJ, Kisic A, Izumi A, Wang KS, Carey KD, Chu AJ. Inhibitors of sterol synthesis. Metabolism of [2,4-3H]5 alpha-cholest-8(14-)-en-3 beta-ol-15-one after intravenous administration to a nonhuman primate. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)68896-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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17
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Inhibitors of sterol synthesis. Metabolism of 5 alpha-cholest-8(14)-en-3 beta-ol-15-one after intravenous administration to bile duct-cannulated rats. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)68897-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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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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19
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Schroepfer GJ, Pajewski TN, Hylarides M, Kisic A. 5 alpha-Cholest-8(14)-en-3 beta-ol-15-one. In vivo conversion to cholesterol upon oral administration to a nonhuman primate. Biochem Biophys Res Commun 1987; 146:1027-32. [PMID: 3619912 DOI: 10.1016/0006-291x(87)90750-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The metabolism of 5 alpha-cholest-8(14)-en-3 beta-ol-15-one (I), a potent inhibitor of cholesterol synthesis with marked hypocholesteremic activity, has been studied in a nonhuman primate. A mixture of [2,4-3H]-I and [4-14C]-cholesterol was administered to a male baboon in the form of a feedball. Blood was samples at 4, 8, 12, 16, and 24 hr. Detailed analyses of the plasma lipids indicated very rapid absorption of I (relative to cholesterol) and metabolism to cholesterol, cholesteryl esters, and esters of I. The labeled cholesterol was characterized by chromatographic techniques and by purification by way of its dibromide derivative. The levels of 3H in plasma associated with I, esters of I, cholesterol, and cholesteryl esters each showed a different time course. By 24 hr after the administration of [2,4-3H]-I, most of the 3H in plasma was associated with cholesterol and cholesteryl esters. The levels of total 3H and 14C in plasma at various times after the administration of the mixture of [2,4-3H]-I and [4-14C]-cholesterol differed markedly with 3H showing a maximum value at 4 hr and 14C showing a maximum value at 24 hr.
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20
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Microsomal enzymes of cholesterol biosynthesis from lanosterol. Solubilization and purification of steroid 8-isomerase. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(19)84586-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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21
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Abstract
Bovine retinas were incubated with 3RS-[5-3H]-mevalonic acid under conditions similar to those previously shown to support opsin biosynthesis in vitro. TLC of the total lipids indicated the formation of numerous radiolabeled components, including sterols, hydrocarbons, and "fatty acid-like material." The nonsaponifiable lipids were analyzed by TLC, GLC, and chromatography on columns of silicic acid-Super Cel, silica gel G-Super Cel-silver nitrate, and alumina-Super Cel-silver nitrate. The major nonsaponifiable components had the chromatographic properties of squalene and "methylated sterols" (i.e., C30, C29, and C28 monohydroxy sterols). Cholesterol represented no more than 1% of the total radioactivity in the nonsaponifiable lipid fraction. The "fatty acid-like material" was derivatized with diazomethane, and the resulting methyl esters were analyzed by GLC before and after catalytic hydrogenation. The radioactivity did not correspond to the normal fatty acids endogenous to the retina, but rather had the chromatographic properties of C15 and C20 isoprenoid acids. These results obtained with intact retinas are consistent with our previous observations concerning mevalonic acid metabolism in cell-free homogenates of bovine retinas.
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22
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23
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Metabolism of mevalonic acid in cell-free homogenates of bovine retinas. Formation of novel isoprenoid acids. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(17)43771-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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24
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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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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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27
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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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28
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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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29
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Pascal RA, Schroepfer GJ. Enzymatic isomerization (delta 7 to delta 8) of the nuclear double bond of 14 alpha-alkyl substituted sterol precursors of cholesterol. Biochem Biophys Res Commun 1980; 94:932-9. [PMID: 7396942 DOI: 10.1016/0006-291x(80)91324-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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30
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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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31
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Pascal RA, Farris CL, Schroepfer GJ. Sterol synthesis: medium-pressure chromatography of C27 sterol precursors of cholesterol on alumina-silver nitrate columns. Anal Biochem 1980; 101:15-22. [PMID: 7356123 DOI: 10.1016/0003-2697(80)90033-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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32
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Chan JT, Spike TE, Trowbridge ST, Schroepfer GJ. Sterol synthesis: studies of the metabolism of 14 alpha-methyl-5 alpha-cholest-7-en-3 beta-ol. J Lipid Res 1979. [DOI: 10.1016/s0022-2275(20)40003-3] [Citation(s) in RCA: 7] [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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33
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Thowsen JR, Schroepfer GJ. Sterol synthesis. High-pressure liquid chromatography of C27 sterol precursors of cholesterol. J Lipid Res 1979. [DOI: 10.1016/s0022-2275(20)40594-2] [Citation(s) in RCA: 10] [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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34
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Huntoon S, Fourcans B, Lutsky B, Parish E, Emery H, Knapp F, Schroepfer G. Sterol Synthesis. Chemical syntheses, spectral properties, and metabolism of 5alpha-cholest-8(14)-en-3beta,15beta-diol and 5alpha-cholest-8(14)-en-3beta,15alpha-diol. J Biol Chem 1978. [DOI: 10.1016/s0021-9258(17)38170-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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35
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Tint GS, Salen G. Evidence for the early reduction of the 24,25 double bond in the conversion of lanosterol to cholesterol in cerebrotendinous xanthomatosis. Metabolism 1977; 26:721-9. [PMID: 865281 DOI: 10.1016/0026-0495(77)90059-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The metabolism of lanosterol and 24,25-dihydrolanosterol (DL) was examined in a patient with cerebrotendinous xanthomatosis after intravenous pulse labeling with a mixture of DL-2-14C and 3S,4S,3R,4R-(4-3H)mevalonate. Sterols were isolated from the feces and purified by silver nitrate thin-layer chromatography, and their identities were confirmed by gas-liquid chromatography and mass spectrometry. Their specific activities were then determined and plotted as a function of time. These isotope ratio measurements and specific activity decay curves were consistent with 24,25-dihydrolanosterol and delta7-cholestenol being intermediates in the synthesis of cholesterol from mevalonate and lanosterol, and they suggested that reduction of the lanosterol side chain may occur as an early step in the synthesis of cholesterol. These results are in contrast to the results reported after the administration of triparanol, a delta24-reductase inhibitor.
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36
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Sliwowski JK, Reddy VR, Caspi E. The in vivo biosynthesis of cholesterol from (3RS,2R) [2-14C,2-3H]mevalonic acid in the brains of rats on normal and protein deficient diets. The stereochemistry of tritium atoms at C-7 and C-15. J Neurochem 1977; 28:1311-6. [PMID: 874493 DOI: 10.1111/j.1471-4159.1977.tb12325.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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37
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Phillips GN, Quiocho FA, Sass RL, Werness P, Emery H, Knapp FF, Schroepfer G. Sterol biosynthesis: Establishment of the structure of 3β-p-bromobenzoyloxy-5α-cholest-8(14)-en-15β-ol. Bioorg Chem 1976. [DOI: 10.1016/0045-2068(76)90011-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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38
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Hsiung HM, Spike TE, Schroepfer GJ. Enzymatic conversion of 5alpha-cholesta-7, 14-dien-3beta-ol to 5alpha-cholesta-8, 14-dien-3beta-ol. Lipids 1975; 10:623-6. [PMID: 1186448 DOI: 10.1007/bf02532727] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
5alpha-Cholesta-7, 14-dien-3beta-ol, previously shown to be efficiently converted to cholesterol upon incubation with rat liver homogenate preparations under aerobic conditions, has been studied as to its possible conversion to 5alpha-cholesta-8, 14-dien-3beta-ol. Efficient conversion was observed upon incubation in the presence of washed mictosomes of rat liver under anaerobic conditions. This observation is of importance in consideration of possible metabolic pathways in the biosythesis of cholesterol.
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39
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Lutsky BN, Hsiung HM, Schroepfer GJ. Inhibition of enzymatic reduction of delta 14-double bond of 5 alpha-cholesta-8,14-dien-3 beta-ol and 5 alpha-cholesta-7,14-dien-3 beta-ol by AY-9944. Lipids 1975; 10:9-11. [PMID: 1123977 DOI: 10.1007/bf02532186] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
AY-994 (trans-1,4-bis-(2-chlorobenzyl-aminomethyl) cyclohexane dihydrochloride), a potent inhibitor of the enzymatic reduction of the delta 7-double bond of delta 5,7-sterols, has been shown to inhibit, at higher concentrations (10-4 M), the enzymatic reduction of the delta 14-double bond of cholesta-8,14-dien-3 beta-ol and cholesta-7,14-dien-3 beta-ol.
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Scala A, Galli-Kienle M, Anastasia M, Galli G. The reversibility of the isomerization of the delta8 to delta7 bond in cholesterol biosynthesis. EUROPEAN JOURNAL OF BIOCHEMISTRY 1974; 48:263-9. [PMID: 4475632 DOI: 10.1111/j.1432-1033.1974.tb03764.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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41
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Bojesen I, Roepstorff P. Identification of C sterols produced by rat renal inner medulla in vitro. BIOCHIMICA ET BIOPHYSICA ACTA 1973; 316:83-90. [PMID: 4722467 DOI: 10.1016/0005-2760(73)90169-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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42
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43
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44
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Lutsky BN, Schroepfer GJ. Enzymatic conversion of 5alpha-cholest-8(14)-en-3beta-o1 to 5alpha-cholesta-8,14-dien-3beta-o1. Lipids 1971; 6:957-9. [PMID: 5163761 DOI: 10.1007/bf02531180] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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45
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Lutsky BN, Martin J, Schroepfer G. Studies of the Metabolism of 5α-Cholesta-8,14-dien-3β-ol and 5α-Cholesta-7,14-dien-3β-ol in Rat Liver Homogenate Preparations. J Biol Chem 1971. [DOI: 10.1016/s0021-9258(19)45907-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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46
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47
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48
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Niehaus WG, Kisic A, Torkelson A, Bednarczyk D, Schroepfer G. Stereospecific Hydration of the Δ9 Double Bond of Oleic Acid. J Biol Chem 1970. [DOI: 10.1016/s0021-9258(18)62921-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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49
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Huntoon S, Schroepfer GJ. Enzymatic conversion of cholest-8(14)-en-3 beta, 15 alpha-diol and cholest-8(14)-en-3 beta, 15 beta-diol to cholesterol. Biochem Biophys Res Commun 1970; 40:476-80. [PMID: 5474796 DOI: 10.1016/0006-291x(70)91033-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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50
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Lee WH, Lutsky BN, Schroepfer GJ. 5α-Cholest-8(14)-en-3β-ol, a Possible Intermediate in the Biosynthesis of Cholesterol. J Biol Chem 1969. [DOI: 10.1016/s0021-9258(18)63585-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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