Claudia Crestini | "Tor Vergata" University of Rome (original) (raw)
Uploads
Papers by Claudia Crestini
Bioorganic & Medicinal Chemistry, 2006
A convenient and efficient application of heterogeneous methylrhenium trioxide (MTO) systems for ... more A convenient and efficient application of heterogeneous methylrhenium trioxide (MTO) systems for the selective oxidation of lignin model compounds and lignins is reported. Environmental friendly and low-cost H 2 O 2 was used as the oxygen atom donor. Overall, the data presented and discussed in this paper point toward the conclusion that the immobilized heterogeneous catalytic systems based on H 2 O 2 /and MTO catalysts are able to extensively oxidize both phenolic and non-phenolic, monomeric, and dimeric, lignin model compounds. Condensed diphenylmethane models were found also extensively oxidized. Technical lignins, such as hydrolytic sugar cane lignin (SCL) and red spruce kraft lignin (RSL), displayed oxidative activity with immobilized MTO catalytic systems. After oxidation, these lignins displayed the formation of more soluble lignin fragments with a high degree of degradation as indicated by the lower contents of aliphatic and condensed OH groups, and the higher amounts of carboxylic acid moieties. Our data indicate that immobilized MTO catalytic systems are significant potential candidates for the development of alternative totally chlorine-free delignification processes and environmentally sustainable lignin selective modification reactions.
Advanced Synthesis & Catalysis, 2008
A convenient and efficient application of heterogeneous poly(4-vinylpyridine), poly(4-vinylpyridi... more A convenient and efficient application of heterogeneous poly(4-vinylpyridine), poly(4-vinylpyridine N-oxide), and polystyrene/methylrhenium trioxide systems for the selective oxidation of tocopherols and tocopherol derivatives to the corresponding ortho-and para-tocopherylquinones is described. Environment friendly, easily available, and low-cost hydrogen peroxide (H 2 O 2 ) was used as the oxygen atom donor. The antiviral activity of the newly synthesized tocopherylquinones and their parent tocopherols against influenza A virus is also reported. On the basis of the biological assay, the activity of tocopherols against influenza virus is higher than that showed by the corresponding tocopherylquinones, thus suggesting, for the first time, a drawback effect of the oxidative metabolism on the antiviral activity of these compounds.
Origins of Life and Evolution of Biospheres, 2011
The thermal condensation of formamide in the presence of mineral borates is reported. The product... more The thermal condensation of formamide in the presence of mineral borates is reported. The products afforded are precursors of nucleic acids, amino acids derivatives and carboxylic acids. The efficiency and the selectivity of the reaction was studied in relation to the elemental composition of the 18 minerals analyzed. The possibility of synthesizing at the same time building blocks of both genetic and metabolic apparatuses, along with the production of amino acids, highlights the interest of the formamide/borate system in prebiotic chemistry.
Bioorganic & Medicinal Chemistry, 2009
Highly oxidized lignans produced during the cytochrome P-450 metabolism in the cells show biologi... more Highly oxidized lignans produced during the cytochrome P-450 metabolism in the cells show biological activities significantly different from those of their parent natural compounds. Lignans precursors of mammalian enterolignans were treated with a methyltrioxorhenium/hydrogen peroxide catalytic system to afford new compounds oxidized at benzylic as well as in arylic positions. The evaluation of the antioxidant and apoptogenic activity by in vivo protocols of these compounds showed some interesting structure-activity relationships related to the oxidation degree of the molecules.
The Porphyrin Handbook, 2003
![Research paper thumbnail of Corrigendum to “Oxidative functionalisation of lignin by layer-by-layer immobilised laccases and laccase microcapsules”[Appl. Catal. A: Gen. 372 (2010) 115–123]](https://attachments.academia-assets.com/42975317/thumbnails/1.jpg)
](
Bioorganic & Medicinal Chemistry, 2006
A convenient and efficient application of heterogeneous methylrhenium trioxide (MTO) systems for ... more A convenient and efficient application of heterogeneous methylrhenium trioxide (MTO) systems for the selective oxidation of lignin model compounds and lignins is reported. Environmental friendly and low-cost H 2 O 2 was used as the oxygen atom donor. Overall, the data presented and discussed in this paper point toward the conclusion that the immobilized heterogeneous catalytic systems based on H 2 O 2 /and MTO catalysts are able to extensively oxidize both phenolic and non-phenolic, monomeric, and dimeric, lignin model compounds. Condensed diphenylmethane models were found also extensively oxidized. Technical lignins, such as hydrolytic sugar cane lignin (SCL) and red spruce kraft lignin (RSL), displayed oxidative activity with immobilized MTO catalytic systems. After oxidation, these lignins displayed the formation of more soluble lignin fragments with a high degree of degradation as indicated by the lower contents of aliphatic and condensed OH groups, and the higher amounts of carboxylic acid moieties. Our data indicate that immobilized MTO catalytic systems are significant potential candidates for the development of alternative totally chlorine-free delignification processes and environmentally sustainable lignin selective modification reactions.
Advanced Synthesis & Catalysis, 2008
A convenient and efficient application of heterogeneous poly(4-vinylpyridine), poly(4-vinylpyridi... more A convenient and efficient application of heterogeneous poly(4-vinylpyridine), poly(4-vinylpyridine N-oxide), and polystyrene/methylrhenium trioxide systems for the selective oxidation of tocopherols and tocopherol derivatives to the corresponding ortho-and para-tocopherylquinones is described. Environment friendly, easily available, and low-cost hydrogen peroxide (H 2 O 2 ) was used as the oxygen atom donor. The antiviral activity of the newly synthesized tocopherylquinones and their parent tocopherols against influenza A virus is also reported. On the basis of the biological assay, the activity of tocopherols against influenza virus is higher than that showed by the corresponding tocopherylquinones, thus suggesting, for the first time, a drawback effect of the oxidative metabolism on the antiviral activity of these compounds.
Origins of Life and Evolution of Biospheres, 2011
The thermal condensation of formamide in the presence of mineral borates is reported. The product... more The thermal condensation of formamide in the presence of mineral borates is reported. The products afforded are precursors of nucleic acids, amino acids derivatives and carboxylic acids. The efficiency and the selectivity of the reaction was studied in relation to the elemental composition of the 18 minerals analyzed. The possibility of synthesizing at the same time building blocks of both genetic and metabolic apparatuses, along with the production of amino acids, highlights the interest of the formamide/borate system in prebiotic chemistry.
Bioorganic & Medicinal Chemistry, 2009
Highly oxidized lignans produced during the cytochrome P-450 metabolism in the cells show biologi... more Highly oxidized lignans produced during the cytochrome P-450 metabolism in the cells show biological activities significantly different from those of their parent natural compounds. Lignans precursors of mammalian enterolignans were treated with a methyltrioxorhenium/hydrogen peroxide catalytic system to afford new compounds oxidized at benzylic as well as in arylic positions. The evaluation of the antioxidant and apoptogenic activity by in vivo protocols of these compounds showed some interesting structure-activity relationships related to the oxidation degree of the molecules.
The Porphyrin Handbook, 2003