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Kjell Wikvall - One of the best experts on this subject based on the ideXlab platform.
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sterol 27 hydroxylase in bile acid biosynthesis mechanism of oxidation of 5 beta Cholestane 3 alpha 7 alpha 12 alpha 27 tetrol into 3 alpha 7 alpha 12 alpha trihydroxy 5 beta cholestanoic acid
Journal of Biological Chemistry, 1993Co-Authors: I Holmbergbetsholtz, Ingemar Björkhem, Erik G Lund, Kjell WikvallAbstract:Abstract The sequence of reactions catalyzed by sterol 27-hydroxylase (CYP27) in the oxidation of 5 beta-Cholestane-3 alpha,7 alpha,12 alpha,27-tetrol into 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid was studied with apparently homogeneous preparations of the cytochrome P-450 from rabbit liver mitochondria. Conditions are described for the formation and characterization of 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-Cholestane-27-al as an enzymatically generated intermediate in the oxidation process. Incubation of 5 beta-Cholestane-3 alpha,7 alpha,12 alpha-triol or 5 beta-Cholestane-3 alpha,7 alpha,12 alpha,27-tetrol with sterol 27-hydroxylase in 18O2 atmosphere resulted in the incorporation of one or two 18O atoms in the carboxyl group of 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid. Similar incubations with 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-Cholestane-27-al resulted in the incorporation of one 18O atom in the 27-carboxyl group. The results strongly indicate that the sterol 27-hydroxylase performs multiple monooxygenations in the conversion of 5 beta-Cholestane-3 alpha,7 alpha,12 alpha-triol into 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid. The following reaction sequence (Reaction 1) at carbon 27 is proposed. [formula: see text] Reaction 1.
Usein M Dzhemilev - One of the best experts on this subject based on the ideXlab platform.
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Catalytic cycloalumination in steroid chemistry II: selective functionalization of 2'-methylidene-2',3'-ethano-(5α)-Cholestane.
Steroids, 2013Co-Authors: Vladimir A D'yakonov, Regina A Tuktarova, Ilgiz I Islamov, Leonard M Khalilov, Usein M DzhemilevAbstract:The catalytic cycloalumination of 2'-methylidene-2',3'-ethano-(5α)-Cholestane with Et3Al catalyzed by Cp2ZrCl2 was performed for the first time to give spiro[2',3'-ethano-(5α)-Cholestane-2',3″-aluminacyclopentane] in a ~75% yield and with high stereoselectivity (>98%). The obtained cyclic organoaluminum compound was transformed in situ into heterocyclic spiran derivatives of 2',3'-ethano-(5α)-Cholestane.
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Catalytic cycloalumination in steroid chemistry II: Selective functionalization of 2′-methylidene-2′,3′-ethano-(5α)-Cholestane
Steroids, 2013Co-Authors: Vladimir A. D’yakonov, Regina A Tuktarova, Ilgiz I Islamov, Leonard M Khalilov, Usein M DzhemilevAbstract:Abstract The catalytic cycloalumination of 2′-methylidene-2′,3′-ethano-(5α)-Cholestane with Et 3 Al catalyzed by Cp 2 ZrCl 2 was performed for the first time to give spiro[2′,3′-ethano-(5α)-Cholestane-2′,3″-aluminacyclopentane] in a ∼75% yield and with high stereoselectivity (>98%). The obtained cyclic organoaluminum compound was transformed in situ into heterocyclic spiran derivatives of 2′,3′-ethano-(5α)-Cholestane.
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Synthesis and transformations of metallacycles 42. Cp2ZrCl2-Catalyzed cycloalumination of 3-methylidenespiro[cyclobutane-1,3′-(5′α)-Cholestane] with Et3Al
Russian Chemical Bulletin, 2013Co-Authors: Usein M Dzhemilev, Regina A Tuktarova, Ilgiz I Islamov, Leonard M Khalilov, Zoya A. Starikova, Vladimir A. D’yakonovAbstract:A Cp2ZrCl2-catalyzed cycloalumination of 3-methylidenespiro[cyclobutane-1,3′-(5′α)-Cholestane] with Et3Al gives 3-ethyl-3-aluminadispiro[cyclopentane-1,1′-cyclobutane-3′,3″-(5″α)-Cholestane] in 84% yield.
I Holmbergbetsholtz - One of the best experts on this subject based on the ideXlab platform.
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sterol 27 hydroxylase in bile acid biosynthesis mechanism of oxidation of 5 beta Cholestane 3 alpha 7 alpha 12 alpha 27 tetrol into 3 alpha 7 alpha 12 alpha trihydroxy 5 beta cholestanoic acid
Journal of Biological Chemistry, 1993Co-Authors: I Holmbergbetsholtz, Ingemar Björkhem, Erik G Lund, Kjell WikvallAbstract:Abstract The sequence of reactions catalyzed by sterol 27-hydroxylase (CYP27) in the oxidation of 5 beta-Cholestane-3 alpha,7 alpha,12 alpha,27-tetrol into 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid was studied with apparently homogeneous preparations of the cytochrome P-450 from rabbit liver mitochondria. Conditions are described for the formation and characterization of 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-Cholestane-27-al as an enzymatically generated intermediate in the oxidation process. Incubation of 5 beta-Cholestane-3 alpha,7 alpha,12 alpha-triol or 5 beta-Cholestane-3 alpha,7 alpha,12 alpha,27-tetrol with sterol 27-hydroxylase in 18O2 atmosphere resulted in the incorporation of one or two 18O atoms in the carboxyl group of 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid. Similar incubations with 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-Cholestane-27-al resulted in the incorporation of one 18O atom in the 27-carboxyl group. The results strongly indicate that the sterol 27-hydroxylase performs multiple monooxygenations in the conversion of 5 beta-Cholestane-3 alpha,7 alpha,12 alpha-triol into 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid. The following reaction sequence (Reaction 1) at carbon 27 is proposed. [formula: see text] Reaction 1.
Erik G Lund - One of the best experts on this subject based on the ideXlab platform.
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sterol 27 hydroxylase in bile acid biosynthesis mechanism of oxidation of 5 beta Cholestane 3 alpha 7 alpha 12 alpha 27 tetrol into 3 alpha 7 alpha 12 alpha trihydroxy 5 beta cholestanoic acid
Journal of Biological Chemistry, 1993Co-Authors: I Holmbergbetsholtz, Ingemar Björkhem, Erik G Lund, Kjell WikvallAbstract:Abstract The sequence of reactions catalyzed by sterol 27-hydroxylase (CYP27) in the oxidation of 5 beta-Cholestane-3 alpha,7 alpha,12 alpha,27-tetrol into 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid was studied with apparently homogeneous preparations of the cytochrome P-450 from rabbit liver mitochondria. Conditions are described for the formation and characterization of 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-Cholestane-27-al as an enzymatically generated intermediate in the oxidation process. Incubation of 5 beta-Cholestane-3 alpha,7 alpha,12 alpha-triol or 5 beta-Cholestane-3 alpha,7 alpha,12 alpha,27-tetrol with sterol 27-hydroxylase in 18O2 atmosphere resulted in the incorporation of one or two 18O atoms in the carboxyl group of 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid. Similar incubations with 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-Cholestane-27-al resulted in the incorporation of one 18O atom in the 27-carboxyl group. The results strongly indicate that the sterol 27-hydroxylase performs multiple monooxygenations in the conversion of 5 beta-Cholestane-3 alpha,7 alpha,12 alpha-triol into 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid. The following reaction sequence (Reaction 1) at carbon 27 is proposed. [formula: see text] Reaction 1.
Ingemar Björkhem - One of the best experts on this subject based on the ideXlab platform.
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sterol 27 hydroxylase in bile acid biosynthesis mechanism of oxidation of 5 beta Cholestane 3 alpha 7 alpha 12 alpha 27 tetrol into 3 alpha 7 alpha 12 alpha trihydroxy 5 beta cholestanoic acid
Journal of Biological Chemistry, 1993Co-Authors: I Holmbergbetsholtz, Ingemar Björkhem, Erik G Lund, Kjell WikvallAbstract:Abstract The sequence of reactions catalyzed by sterol 27-hydroxylase (CYP27) in the oxidation of 5 beta-Cholestane-3 alpha,7 alpha,12 alpha,27-tetrol into 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid was studied with apparently homogeneous preparations of the cytochrome P-450 from rabbit liver mitochondria. Conditions are described for the formation and characterization of 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-Cholestane-27-al as an enzymatically generated intermediate in the oxidation process. Incubation of 5 beta-Cholestane-3 alpha,7 alpha,12 alpha-triol or 5 beta-Cholestane-3 alpha,7 alpha,12 alpha,27-tetrol with sterol 27-hydroxylase in 18O2 atmosphere resulted in the incorporation of one or two 18O atoms in the carboxyl group of 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid. Similar incubations with 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-Cholestane-27-al resulted in the incorporation of one 18O atom in the 27-carboxyl group. The results strongly indicate that the sterol 27-hydroxylase performs multiple monooxygenations in the conversion of 5 beta-Cholestane-3 alpha,7 alpha,12 alpha-triol into 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid. The following reaction sequence (Reaction 1) at carbon 27 is proposed. [formula: see text] Reaction 1.