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Marijn M Speeckaert - One of the best experts on this subject based on the ideXlab platform.
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Mechanisms and consequences of Carbamoylation
Nature Reviews Nephrology, 2017Co-Authors: Sigurd E Delanghe, Joris R Delanghe, Reinhart Speeckaert, Wim Van Biesen, Marijn M SpeeckaertAbstract:Protein Carbamoylation is a non-enzymatic post-translational modification that binds isocyanic acid, which can be derived from the dissociation of urea or from the myeloperoxidase-mediated catabolism of thiocyanate, to the free amino groups of a multitude of proteins. Although the term 'Carbamoylation' is usually replaced by the term “carbamylation” in the literature, carbamylation refers to a different chemical reaction (the reversible interaction of CO_2 with α and ε-amino groups of proteins). Depending on the altered molecule (for example, collagen, erythropoietin, haemoglobin, low-density lipoprotein or high-density lipoprotein), Carbamoylation can have different pathophysiological effects. Carbamoylated proteins have been linked to atherosclerosis, lipid metabolism, immune system dysfunction (such as inhibition of the classical complement pathway, inhibition of complement-dependent rituximab cytotoxicity, reduced oxidative neutrophil burst, and the formation of anti-carbamoylated protein antibodies) and renal fibrosis. In this Review, we discuss the Carbamoylation process and evaluate the available biomarkers of Carbamoylation (for example, homocitrulline, the percentage of carbamoylated albumin, carbamoylated haemoglobin, and carbamoylated low-density lipoprotein). We also discuss the relationship between Carbamoylation and the occurrence of cardiovascular events and mortality in patients with chronic kidney disease and assess the effects of strategies to lower the Carbamoylation load. Patients with chronic kidney disease have elevated levels of carbamoylated proteins. Here the authors review the mechanisms of Carbamoylation, the effects of this post-translational modification on renal function and strategies to reduce the Carbamoylation load. Carbamoylation is a non-enzymatic reaction during which a carbamoyl moiety is added to proteins, peptides or amino acids; this post-translational molecular modification contributes to the molecular ageing of proteins Carbamoylation-derived products are formed by the reaction of proteins, peptides or amino acids with isocyanic acid, which originates from urea or by oxidation of thiocyanate by myeloperoxidase in inflammatory conditions and in atherosclerotic plaques Carbamoylation has important effects on the immune system, atherosclerosis, lipid metabolism, and the progression of chronic kidney disease Carbamoylation-derived products are emerging as important markers of survival in the general population as well as in patients on dialysis
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mechanisms and consequences of Carbamoylation
Nature Reviews Nephrology, 2017Co-Authors: Sigurd E Delanghe, Joris R Delanghe, Reinhart Speeckaert, Wim Van Biesen, Marijn M SpeeckaertAbstract:Protein Carbamoylation is a non-enzymatic post-translational modification that binds isocyanic acid, which can be derived from the dissociation of urea or from the myeloperoxidase-mediated catabolism of thiocyanate, to the free amino groups of a multitude of proteins. Although the term 'Carbamoylation' is usually replaced by the term "carbamylation" in the literature, carbamylation refers to a different chemical reaction (the reversible interaction of CO2 with α and e-amino groups of proteins). Depending on the altered molecule (for example, collagen, erythropoietin, haemoglobin, low-density lipoprotein or high-density lipoprotein), Carbamoylation can have different pathophysiological effects. Carbamoylated proteins have been linked to atherosclerosis, lipid metabolism, immune system dysfunction (such as inhibition of the classical complement pathway, inhibition of complement-dependent rituximab cytotoxicity, reduced oxidative neutrophil burst, and the formation of anti-carbamoylated protein antibodies) and renal fibrosis. In this Review, we discuss the Carbamoylation process and evaluate the available biomarkers of Carbamoylation (for example, homocitrulline, the percentage of carbamoylated albumin, carbamoylated haemoglobin, and carbamoylated low-density lipoprotein). We also discuss the relationship between Carbamoylation and the occurrence of cardiovascular events and mortality in patients with chronic kidney disease and assess the effects of strategies to lower the Carbamoylation load.
Hermenegildo Garcia - One of the best experts on this subject based on the ideXlab platform.
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activity of ceria and ceria supported gold nanoparticles for the Carbamoylation of aliphatic amines by dimethyl carbonate
Pure and Applied Chemistry, 2011Co-Authors: Raquel Juarez, Avelino Corma, Hermenegildo GarciaAbstract:Aliphatic amines react sluggishly with dimethyl carbonate (DMC) to give a mix- ture of N-methylation and Carbamoylation. Nanoparticulated ceria as catalyst increases, in general, conversion and selectivity toward Carbamoylation. This increase in catalytic activity and selectivity toward Carbamoylation is even increased by deposition of Au nanoparticles on ceria. However, in contrast to aromatic amines for which a complete selectivity toward car- bamoylation using ceria-supported Au nanoparticles can be achieved, the catalytic car- bamoylation of aliphatic amines by ceria-supported Au nanoparticles occurs only with mod- erate selectivity.
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continuous flow Carbamoylation of aniline by dimethyl carbonate using a microreactor coated with a thin film of ceria supported gold nanoparticles
Catalysis Today, 2011Co-Authors: Raquel Juarez, Helmut Pennemann, Hermenegildo GarciaAbstract:Abstract Selective Carbamoylation of aniline by dimethyl carbonate has been performed under continuous flow using a microreactor having 10 μm microchannels and 4 ml of total volume. Nanoparticulated ceria and gold nanoparticles supported on nanoparticulated ceria that have proved to be highly selective in batch reactions were tested as catalysts. The catalyst coating was deposited as thin film on the stainless steel microreactor plate that was previously activated by heating at 700 °C for 2 h. It was observed that at 120 °C and 5 bar pressure, both catalysts were stable over long times on stream reaching maximum conversions about 35%.
Sigurd E Delanghe - One of the best experts on this subject based on the ideXlab platform.
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Mechanisms and consequences of Carbamoylation
Nature Reviews Nephrology, 2017Co-Authors: Sigurd E Delanghe, Joris R Delanghe, Reinhart Speeckaert, Wim Van Biesen, Marijn M SpeeckaertAbstract:Protein Carbamoylation is a non-enzymatic post-translational modification that binds isocyanic acid, which can be derived from the dissociation of urea or from the myeloperoxidase-mediated catabolism of thiocyanate, to the free amino groups of a multitude of proteins. Although the term 'Carbamoylation' is usually replaced by the term “carbamylation” in the literature, carbamylation refers to a different chemical reaction (the reversible interaction of CO_2 with α and ε-amino groups of proteins). Depending on the altered molecule (for example, collagen, erythropoietin, haemoglobin, low-density lipoprotein or high-density lipoprotein), Carbamoylation can have different pathophysiological effects. Carbamoylated proteins have been linked to atherosclerosis, lipid metabolism, immune system dysfunction (such as inhibition of the classical complement pathway, inhibition of complement-dependent rituximab cytotoxicity, reduced oxidative neutrophil burst, and the formation of anti-carbamoylated protein antibodies) and renal fibrosis. In this Review, we discuss the Carbamoylation process and evaluate the available biomarkers of Carbamoylation (for example, homocitrulline, the percentage of carbamoylated albumin, carbamoylated haemoglobin, and carbamoylated low-density lipoprotein). We also discuss the relationship between Carbamoylation and the occurrence of cardiovascular events and mortality in patients with chronic kidney disease and assess the effects of strategies to lower the Carbamoylation load. Patients with chronic kidney disease have elevated levels of carbamoylated proteins. Here the authors review the mechanisms of Carbamoylation, the effects of this post-translational modification on renal function and strategies to reduce the Carbamoylation load. Carbamoylation is a non-enzymatic reaction during which a carbamoyl moiety is added to proteins, peptides or amino acids; this post-translational molecular modification contributes to the molecular ageing of proteins Carbamoylation-derived products are formed by the reaction of proteins, peptides or amino acids with isocyanic acid, which originates from urea or by oxidation of thiocyanate by myeloperoxidase in inflammatory conditions and in atherosclerotic plaques Carbamoylation has important effects on the immune system, atherosclerosis, lipid metabolism, and the progression of chronic kidney disease Carbamoylation-derived products are emerging as important markers of survival in the general population as well as in patients on dialysis
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mechanisms and consequences of Carbamoylation
Nature Reviews Nephrology, 2017Co-Authors: Sigurd E Delanghe, Joris R Delanghe, Reinhart Speeckaert, Wim Van Biesen, Marijn M SpeeckaertAbstract:Protein Carbamoylation is a non-enzymatic post-translational modification that binds isocyanic acid, which can be derived from the dissociation of urea or from the myeloperoxidase-mediated catabolism of thiocyanate, to the free amino groups of a multitude of proteins. Although the term 'Carbamoylation' is usually replaced by the term "carbamylation" in the literature, carbamylation refers to a different chemical reaction (the reversible interaction of CO2 with α and e-amino groups of proteins). Depending on the altered molecule (for example, collagen, erythropoietin, haemoglobin, low-density lipoprotein or high-density lipoprotein), Carbamoylation can have different pathophysiological effects. Carbamoylated proteins have been linked to atherosclerosis, lipid metabolism, immune system dysfunction (such as inhibition of the classical complement pathway, inhibition of complement-dependent rituximab cytotoxicity, reduced oxidative neutrophil burst, and the formation of anti-carbamoylated protein antibodies) and renal fibrosis. In this Review, we discuss the Carbamoylation process and evaluate the available biomarkers of Carbamoylation (for example, homocitrulline, the percentage of carbamoylated albumin, carbamoylated haemoglobin, and carbamoylated low-density lipoprotein). We also discuss the relationship between Carbamoylation and the occurrence of cardiovascular events and mortality in patients with chronic kidney disease and assess the effects of strategies to lower the Carbamoylation load.
TETSUO YOSHIMITSU - One of the best experts on this subject based on the ideXlab platform.
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Total synthesis of (±)-kainic acid: a photochemical C-H Carbamoylation approach.
Organic Letters, 2011Co-Authors: T. Kamon, Yayoi Irifune, Tetsuaki Tanaka, TETSUO YOSHIMITSUAbstract:A novel photochemical C–H Carbamoylation of an octahydroisoindole derivative with PhNCO has allowed the authors to provide a unique access to a highly functionalized proline motif from which total synthesis of (±)-kainic acid, a bioactive marine alkaloid, has been accomplished.
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total synthesis of kainic acid a photochemical c h Carbamoylation approach
Organic Letters, 2011Co-Authors: T. Kamon, Yayoi Irifune, Tetsuaki Tanaka, TETSUO YOSHIMITSUAbstract:A novel photochemical C–H Carbamoylation of an octahydroisoindole derivative with PhNCO has allowed the authors to provide a unique access to a highly functionalized proline motif from which total synthesis of (±)-kainic acid, a bioactive marine alkaloid, has been accomplished.
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radical fixation of functionalized carbon resources alpha sp3c h Carbamoylation of tertiary amines with aryl isocyanates
Organic Letters, 2007Co-Authors: TETSUO YOSHIMITSU, Kenichi Matsuda, Hiroto Nagaoka, Koji Tsukamoto, Tetsuaki TanakaAbstract:A new Carbamoylation of tertiary amines is reported. This rare C−H transformation features the direct generation of α-aminoalkyl radicals from tertiary amines, followed by the addition of the resultant nucleophilic radicals to isocyanates, enabling unique access to N,N-dialkylated amino acid derivatives. The authors put forward a mechanistic proposal that is based on the isolation of borinamides produced by capturing nitrogen radical intermediates with Et3B. The present transformation provides a novel one-step process for producing mepivacaine, a clinically important local anesthetic, from readily available materials.
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Taxol
Angewandte Chemie (International ed. in English), 1995Co-Authors: T. Kamon, Yayoi Irifune, Tetsuaki Tanaka, TETSUO YOSHIMITSUAbstract:A novel photochemical C-H Carbamoylation of an octahydroisoindole derivative with PhNCO has allowed the authors to provide a unique access to a highly functionalized proline motif from which total synthesis of (±)-kainic acid, a bioactive marine alkaloid, has been accomplished.
Raquel Juarez - One of the best experts on this subject based on the ideXlab platform.
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activity of ceria and ceria supported gold nanoparticles for the Carbamoylation of aliphatic amines by dimethyl carbonate
Pure and Applied Chemistry, 2011Co-Authors: Raquel Juarez, Avelino Corma, Hermenegildo GarciaAbstract:Aliphatic amines react sluggishly with dimethyl carbonate (DMC) to give a mix- ture of N-methylation and Carbamoylation. Nanoparticulated ceria as catalyst increases, in general, conversion and selectivity toward Carbamoylation. This increase in catalytic activity and selectivity toward Carbamoylation is even increased by deposition of Au nanoparticles on ceria. However, in contrast to aromatic amines for which a complete selectivity toward car- bamoylation using ceria-supported Au nanoparticles can be achieved, the catalytic car- bamoylation of aliphatic amines by ceria-supported Au nanoparticles occurs only with mod- erate selectivity.
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continuous flow Carbamoylation of aniline by dimethyl carbonate using a microreactor coated with a thin film of ceria supported gold nanoparticles
Catalysis Today, 2011Co-Authors: Raquel Juarez, Helmut Pennemann, Hermenegildo GarciaAbstract:Abstract Selective Carbamoylation of aniline by dimethyl carbonate has been performed under continuous flow using a microreactor having 10 μm microchannels and 4 ml of total volume. Nanoparticulated ceria and gold nanoparticles supported on nanoparticulated ceria that have proved to be highly selective in batch reactions were tested as catalysts. The catalyst coating was deposited as thin film on the stainless steel microreactor plate that was previously activated by heating at 700 °C for 2 h. It was observed that at 120 °C and 5 bar pressure, both catalysts were stable over long times on stream reaching maximum conversions about 35%.