The Experts below are selected from a list of 2139 Experts worldwide ranked by ideXlab platform
Hiroaki Ohno - One of the best experts on this subject based on the ideXlab platform.
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formal total synthesis of Lysergic Acid via zinc ii mediated regioselective ring opening reduction of 2 alkynyl 3 indolyloxirane
Journal of Organic Chemistry, 2011Co-Authors: Akira Iwata, Shinsuke Inuki, Shinya Oishi, Nobutaka Fujii, Hiroaki OhnoAbstract:Asymmetric formal synthesis of (+)-Lysergic Acid was achieved with a reductive ring-opening reaction of chiral 2-alkynyl-3-indolyloxirane with NaBH(3)CN as the key step. With Zn(OTf)(2) as an additive, the ring-opening reaction proceeded regioselectively at the 3-position to give the corresponding propargyl alcohol, which was a precursor of the allenic amide for palladium-catalyzed domino cyclization to construct the ergot alkaloid core structure.
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enantioselective total synthesis of Lysergic Acid lysergol and isolysergol by palladium catalyzed domino cyclization of allenes bearing amino and bromoindolyl groups
Journal of Organic Chemistry, 2011Co-Authors: Shinsuke Inuki, Akira Iwata, Shinya Oishi, Hiroaki OhnoAbstract:Enantioselective total synthesis of the biologically important indole alkaloids (+)-lysergol, (+)-isolysergol, and (+)-Lysergic Acid is described. Key features of these total synthesis include (1) a facile synthesis of a chiral 1,3-amino alcohol via the Pd(0)- and In(I)-mediated reductive coupling reaction between l-serine-derived 2-ethynylaziridine and formaldehyde; (2) the Cr(II)/Ni(0)-mediated Nozaki−Hiyama−Kishi (NHK) reaction of an indole-3-acetaldehyde with iodoalkyne; and (3) Pd(0)-catalyzed domino cyclization of an allene bearing amino and bromoindolyl groups. This domino cyclization enabled direct construction of the C/D ring system of the ergot alkaloids skeleton, as well as the creation of the C5 stereogenic center with transfer of the allenic axial chirality to the central chirality.
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total synthesis of Lysergic Acid lysergol and isolysergol by palladium catalyzed domino cyclization of amino allenes bearing a bromoindolyl group
Organic Letters, 2008Co-Authors: Shinsuke Inuki, Shinya Oishi, Nobutaka Fujii, Hiroaki OhnoAbstract:Ergot alkaloids and their synthetic analogs have been reported to exhibit broad biological activity. We investigated direct construction of the C/D ring system of ergot alkaloids based on palladium-catalyzed domino cyclization of amino allenes. With this biscyclization as the key step, total synthesis of (±)-Lysergic Acid, (±)-lysergol, and (±)-isolysergol was achieved.
Wulf-dieter Moll - One of the best experts on this subject based on the ideXlab platform.
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Rhodococcus erythropolis MTHt3 biotransforms ergopeptines to Lysergic Acid
BMC Microbiology, 2015Co-Authors: Michaela Thamhesl, Elisabeth Apfelthaler, Heidi Elisabeth Schwartz-zimmermann, Elisavet Kunz-vekiru, Wolfgang Kneifel, Gerd Schatzmayr, Rudolf Krska, Wulf-dieter MollAbstract:Background Ergopeptines are a predominant class of ergot alkaloids produced by tall fescue grass endophyte Neotyphodium coenophialum or cereal pathogen Claviceps purpurea . The vasoconstrictive activity of ergopeptines makes them toxic for mammals, and they can be a problem in animal husbandry. Results We isolated an ergopeptine degrading bacterial strain, MTHt3, and classified it, based on its 16S rDNA sequence, as a strain of Rhodococcus erythropolis ( Nocardiaceae, Actinobacteria ). For strain isolation, mixed microbial cultures were obtained from artificially ergot alkaloid-enriched soil, and provided with the ergopeptine ergotamine in mineral medium for enrichment. Individual colonies derived from such mixed cultures were screened for ergotamine degradation by high performance liquid chromatography and fluorescence detection. R. erythropolis MTHt3 converted ergotamine to ergine (Lysergic Acid amide) and further to Lysergic Acid, which accumulated as an end product. No other tested R. erythropolis strain degraded ergotamine. R. erythropolis MTHt3 degraded all ergopeptines found in an ergot extract, namely ergotamine, ergovaline, ergocristine, ergocryptine, ergocornine, and ergosine, but the simpler Lysergic Acid derivatives agroclavine, chanoclavine, and ergometrine were not degraded. Temperature and pH dependence of ergotamine and ergine bioconversion activity was different for the two reactions. Conclusions Degradation of ergopeptines to ergine is a previously unknown microbial reaction. The reaction end product, Lysergic Acid, has no or much lower vasoconstrictive activity than ergopeptines. If the genes encoding enzymes for ergopeptine catabolism can be cloned and expressed in recombinant hosts, application of ergopeptine and ergine degrading enzymes for reduction of toxicity of ergot alkaloid-contaminated animal feed may be feasible.
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Rhodococcus erythropolis MTHt3 biotransforms ergopeptines to Lysergic Acid
BMC Microbiology, 2015Co-Authors: Michaela Thamhesl, Elisabeth Apfelthaler, Heidi Elisabeth Schwartz-zimmermann, Elisavet Kunz-vekiru, Wolfgang Kneifel, Gerd Schatzmayr, Rudolf Krska, Wulf-dieter MollAbstract:Ergopeptines are a predominant class of ergot alkaloids produced by tall fescue grass endophyte Neotyphodium coenophialum or cereal pathogen Claviceps purpurea. The vasoconstrictive activity of ergopeptines makes them toxic for mammals, and they can be a problem in animal husbandry. We isolated an ergopeptine degrading bacterial strain, MTHt3, and classified it, based on its 16S rDNA sequence, as a strain of Rhodococcus erythropolis (Nocardiaceae, Actinobacteria). For strain isolation, mixed microbial cultures were obtained from artificially ergot alkaloid-enriched soil, and provided with the ergopeptine ergotamine in mineral medium for enrichment. Individual colonies derived from such mixed cultures were screened for ergotamine degradation by high performance liquid chromatography and fluorescence detection. R. erythropolis MTHt3 converted ergotamine to ergine (Lysergic Acid amide) and further to Lysergic Acid, which accumulated as an end product. No other tested R. erythropolis strain degraded ergotamine. R. erythropolis MTHt3 degraded all ergopeptines found in an ergot extract, namely ergotamine, ergovaline, ergocristine, ergocryptine, ergocornine, and ergosine, but the simpler Lysergic Acid derivatives agroclavine, chanoclavine, and ergometrine were not degraded. Temperature and pH dependence of ergotamine and ergine bioconversion activity was different for the two reactions. Degradation of ergopeptines to ergine is a previously unknown microbial reaction. The reaction end product, Lysergic Acid, has no or much lower vasoconstrictive activity than ergopeptines. If the genes encoding enzymes for ergopeptine catabolism can be cloned and expressed in recombinant hosts, application of ergopeptine and ergine degrading enzymes for reduction of toxicity of ergot alkaloid-contaminated animal feed may be feasible.
Philip Garner - One of the best experts on this subject based on the ideXlab platform.
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asymmetric synthesis of Lysergic Acid via an intramolecular 3 2 dipolar cycloaddition ring expansion sequence
Organic Letters, 2021Co-Authors: Upendra Rathnayake, Philip GarnerAbstract:An effective, potentially scalable asymmetric synthesis of Lysergic Acid, a core component of the ergot alkaloid family, is reported. The synthesis features the strategic combination of an intramolecular azomethine ylide cycloaddition and Cossy-Charette ring expansion to assemble the target's C- and D-rings. Simple functional group manipulation produced a compound that had been converted to Lysergic Acid in four steps, thus constituting a formal synthesis of the natural product. The strategy may be used to prepare novel ergot analogues that include unnatural antipodes and may be more amenable to analogue generation relative to prior approaches.
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Asymmetric Synthesis of Lysergic Acid via an Intramolecular (3+2) Dipolar Cycloaddition/Ring-Expansion Sequence
'American Chemical Society (ACS)', 2021Co-Authors: Upendra Rathnayake, Philip GarnerAbstract:An effective, potentially scalable asymmetric synthesis of Lysergic Acid, a core component of the ergot alkaloid family, is reported. The synthesis features the strategic combination of an intramolecular azomethine ylide cycloaddition and Cossy–Charette ring expansion to assemble the target’s C- and D-rings. Simple functional group manipulation produced a compound that had been converted to Lysergic Acid in four steps, thus constituting a formal synthesis of the natural product. The strategy may be used to prepare novel ergot analogues that include unnatural antipodes and may be more amenable to analogue generation relative to prior approaches
Shinsuke Inuki - One of the best experts on this subject based on the ideXlab platform.
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total synthesis of Lysergic Acid lysergol and isolysergol
2012Co-Authors: Shinsuke InukiAbstract:Enantioselective total synthesis of the biologically important indole alkaloids, (+)-lysergol, (+)-isolysergol and (+)-Lysergic Acid is described. Key features of these total synthesis include: (1) a facile synthesis of a chiral 1,3-amino alcohol via the Pd(0) and In(I)-mediated reductive coupling reaction between l-serine-derived 2-ethynylaziridine and formaldehyde; (2) the Cr(II)/Ni(0)-mediated Nozaki−Hiyama−Kishi (NHK) reaction of an indole-3-acetaldehyde with iodoalkyne; and (3) Pd(0)-catalyzed domino cyclization of an amino allene bearing a bromoindolyl group. This domino cyclization enabled direct construction of the C/D ring system of the ergot alkaloids skeleton as well as the creation of the C5 stereogenic center with transfer of the allenic axial chirality to the central chirality.
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formal total synthesis of Lysergic Acid via zinc ii mediated regioselective ring opening reduction of 2 alkynyl 3 indolyloxirane
Journal of Organic Chemistry, 2011Co-Authors: Akira Iwata, Shinsuke Inuki, Shinya Oishi, Nobutaka Fujii, Hiroaki OhnoAbstract:Asymmetric formal synthesis of (+)-Lysergic Acid was achieved with a reductive ring-opening reaction of chiral 2-alkynyl-3-indolyloxirane with NaBH(3)CN as the key step. With Zn(OTf)(2) as an additive, the ring-opening reaction proceeded regioselectively at the 3-position to give the corresponding propargyl alcohol, which was a precursor of the allenic amide for palladium-catalyzed domino cyclization to construct the ergot alkaloid core structure.
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enantioselective total synthesis of Lysergic Acid lysergol and isolysergol by palladium catalyzed domino cyclization of allenes bearing amino and bromoindolyl groups
Journal of Organic Chemistry, 2011Co-Authors: Shinsuke Inuki, Akira Iwata, Shinya Oishi, Hiroaki OhnoAbstract:Enantioselective total synthesis of the biologically important indole alkaloids (+)-lysergol, (+)-isolysergol, and (+)-Lysergic Acid is described. Key features of these total synthesis include (1) a facile synthesis of a chiral 1,3-amino alcohol via the Pd(0)- and In(I)-mediated reductive coupling reaction between l-serine-derived 2-ethynylaziridine and formaldehyde; (2) the Cr(II)/Ni(0)-mediated Nozaki−Hiyama−Kishi (NHK) reaction of an indole-3-acetaldehyde with iodoalkyne; and (3) Pd(0)-catalyzed domino cyclization of an allene bearing amino and bromoindolyl groups. This domino cyclization enabled direct construction of the C/D ring system of the ergot alkaloids skeleton, as well as the creation of the C5 stereogenic center with transfer of the allenic axial chirality to the central chirality.
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total synthesis of Lysergic Acid lysergol and isolysergol by palladium catalyzed domino cyclization of amino allenes bearing a bromoindolyl group
Organic Letters, 2008Co-Authors: Shinsuke Inuki, Shinya Oishi, Nobutaka Fujii, Hiroaki OhnoAbstract:Ergot alkaloids and their synthetic analogs have been reported to exhibit broad biological activity. We investigated direct construction of the C/D ring system of ergot alkaloids based on palladium-catalyzed domino cyclization of amino allenes. With this biscyclization as the key step, total synthesis of (±)-Lysergic Acid, (±)-lysergol, and (±)-isolysergol was achieved.
Michaela Thamhesl - One of the best experts on this subject based on the ideXlab platform.
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Rhodococcus erythropolis MTHt3 biotransforms ergopeptines to Lysergic Acid
BMC Microbiology, 2015Co-Authors: Michaela Thamhesl, Elisabeth Apfelthaler, Heidi Elisabeth Schwartz-zimmermann, Elisavet Kunz-vekiru, Wolfgang Kneifel, Gerd Schatzmayr, Rudolf Krska, Wulf-dieter MollAbstract:Background Ergopeptines are a predominant class of ergot alkaloids produced by tall fescue grass endophyte Neotyphodium coenophialum or cereal pathogen Claviceps purpurea . The vasoconstrictive activity of ergopeptines makes them toxic for mammals, and they can be a problem in animal husbandry. Results We isolated an ergopeptine degrading bacterial strain, MTHt3, and classified it, based on its 16S rDNA sequence, as a strain of Rhodococcus erythropolis ( Nocardiaceae, Actinobacteria ). For strain isolation, mixed microbial cultures were obtained from artificially ergot alkaloid-enriched soil, and provided with the ergopeptine ergotamine in mineral medium for enrichment. Individual colonies derived from such mixed cultures were screened for ergotamine degradation by high performance liquid chromatography and fluorescence detection. R. erythropolis MTHt3 converted ergotamine to ergine (Lysergic Acid amide) and further to Lysergic Acid, which accumulated as an end product. No other tested R. erythropolis strain degraded ergotamine. R. erythropolis MTHt3 degraded all ergopeptines found in an ergot extract, namely ergotamine, ergovaline, ergocristine, ergocryptine, ergocornine, and ergosine, but the simpler Lysergic Acid derivatives agroclavine, chanoclavine, and ergometrine were not degraded. Temperature and pH dependence of ergotamine and ergine bioconversion activity was different for the two reactions. Conclusions Degradation of ergopeptines to ergine is a previously unknown microbial reaction. The reaction end product, Lysergic Acid, has no or much lower vasoconstrictive activity than ergopeptines. If the genes encoding enzymes for ergopeptine catabolism can be cloned and expressed in recombinant hosts, application of ergopeptine and ergine degrading enzymes for reduction of toxicity of ergot alkaloid-contaminated animal feed may be feasible.
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Rhodococcus erythropolis MTHt3 biotransforms ergopeptines to Lysergic Acid
BMC Microbiology, 2015Co-Authors: Michaela Thamhesl, Elisabeth Apfelthaler, Heidi Elisabeth Schwartz-zimmermann, Elisavet Kunz-vekiru, Wolfgang Kneifel, Gerd Schatzmayr, Rudolf Krska, Wulf-dieter MollAbstract:Ergopeptines are a predominant class of ergot alkaloids produced by tall fescue grass endophyte Neotyphodium coenophialum or cereal pathogen Claviceps purpurea. The vasoconstrictive activity of ergopeptines makes them toxic for mammals, and they can be a problem in animal husbandry. We isolated an ergopeptine degrading bacterial strain, MTHt3, and classified it, based on its 16S rDNA sequence, as a strain of Rhodococcus erythropolis (Nocardiaceae, Actinobacteria). For strain isolation, mixed microbial cultures were obtained from artificially ergot alkaloid-enriched soil, and provided with the ergopeptine ergotamine in mineral medium for enrichment. Individual colonies derived from such mixed cultures were screened for ergotamine degradation by high performance liquid chromatography and fluorescence detection. R. erythropolis MTHt3 converted ergotamine to ergine (Lysergic Acid amide) and further to Lysergic Acid, which accumulated as an end product. No other tested R. erythropolis strain degraded ergotamine. R. erythropolis MTHt3 degraded all ergopeptines found in an ergot extract, namely ergotamine, ergovaline, ergocristine, ergocryptine, ergocornine, and ergosine, but the simpler Lysergic Acid derivatives agroclavine, chanoclavine, and ergometrine were not degraded. Temperature and pH dependence of ergotamine and ergine bioconversion activity was different for the two reactions. Degradation of ergopeptines to ergine is a previously unknown microbial reaction. The reaction end product, Lysergic Acid, has no or much lower vasoconstrictive activity than ergopeptines. If the genes encoding enzymes for ergopeptine catabolism can be cloned and expressed in recombinant hosts, application of ergopeptine and ergine degrading enzymes for reduction of toxicity of ergot alkaloid-contaminated animal feed may be feasible.
