Acetophenone
Mostrando 13-24 de 40 artigos, teses e dissertações.
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13. Efecto de solvente sobre la descomposición térmica de trans-3,6-dimetil-3,6-difenil-1,2,4,5-tetraoxaciclohexano en solución
The thermal decomposition reaction of trans-3,6-dimethyl-3,6-diphenyl-1,2,4,5-tetraoxacyclohexane (acetophenone cyclic diperoxide, DPAF), in different solvents (methanol, 1,4-dioxane, acetonitrile and 2-propanol/benzene mixtures) in the initial concentration and temperature ranges of (4.2-10.5) x 10-3 M and 140.0 to 185.0 ºC, respectively, follows a pseudo
Química Nova. Publicado em: 2004-12
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14. Important volateis composites for the aroma of jenipapo (American Genipa L.) e murici (crassifolia Byrsonima L. RICH). / Compostos volateis importantes para o aroma de jenipapo (Genipa americana L.) e murici (Byrsonima crassifolia L. RICH).
The volatile compounds are responsible for the characteristic flavor of food. They are present in a wide interval of concentration, possessing varied chemical structure, beyond of being, generally heating labil. Usually the flavour of a product is constituted by hundreds of volatile compounds. However, only some compounds efftectivelly contribute to the over
Publicado em: 2004
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15. Sintese de (R)-(-)-ariletanolaminas via redução microbiologica utilizando-se fermento de pão (Saccharomyces cerevisiae) na criação do centro quiral
This work describes the synthesis of (R)-(-)-Arylethanolamines which present sympathomimetic properties and form an important class of biologically active compounds. The initial step of this work was the creation of the asymmetric center, by microbiological reduction of derivatives of acetophenone (ArCOCH2X where X= CI or N3) using baker s yeast (Saccharomyc
Publicado em: 1991
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16. Adição de silil-enoleteres a aldiminas aromaticas ativadas : sintese, C-metilação e redução estereosseletiva do B-aminocetonas secundarias N-aril-substituidas
A novel entry into secondary N-Aryl-b-aminoketones (109-123) is described which features the addition of silyleno- lethers to aromatic aldimines activated by trimethylsilyl trifIuoromethanesulphonate (TMSOTf). Good yields (33-98%) achieved whith catalitic TMSOTf (15 mol%), while only BF3:OEt2 and TeCI4 yielded b-aminoketones among the Lewis acid employed (Ti
Publicado em: 1989
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17. Bioconversion of Cinnamic Acid to Acetophenone by a Pseudomonad: Microbial Production of a Natural Flavor Compound
A mutant derivative of a novel pseudomonad isolated from the soil accumulated acetophenone when supplied with cinnamic acid. The microorganism has been identified as an unclassified Pseudomonas sp., similar to Pseudomonas acidovorans. Mass spectrum analysis of the product acetophenone derived from catabolism of cinnamic acid in the presence of 18O2 or H218O
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18. Microbial conversion of ethylbenzene to 1-phenethanol and acetophenone by Nocardia tartaricans ATCC 31190.
A culture of Nocardia tartaricans ATCC 31190 was capable of catalyzing the conversion of ethylbenzene to 1-phenethanol and acetophenone while growing in a shake flask culture with hexadecane as the source of carbon and energy. This subterminal oxidative reaction with ethylbenzene appears not to have been previously reported for Nocardia species. When N. tart
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19. Toluene and ethylbenzene oxidation by purified naphthalene dioxygenase from Pseudomonas sp. strain NCIB 9816-4.
Purified naphthalene dioxygenase (NDO) from Pseudomonas sp. strain NCIB 9816-4 oxidized toluene to benzyl alcohol and benzaldehyde by reactions involving benzylic monooxygenation and dioxygen-dependent alcohol oxidation, respectively. Xylene and nitrotoluene isomers were also oxidized to substituted benzyl alcohol and benzaldehyde derivatives. NDO oxidized e
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20. In Vitro Studies on the Initial Reactions of Anaerobic Ethylbenzene Mineralization
Anaerobic mineralization of ethylbenzene by the denitrifying bacterium Azoarcus sp. strain EB1 was recently shown to be initiated by dehydrogenation of ethylbenzene to 1-phenylethanol. 1-Phenylethanol is converted to benzoate (benzoyl coenzyme A) via acetophenone as transient intermediate. We developed in vitro assays to examine ethylbenzene dehydrogenase an
American Society for Microbiology.
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21. Targeted mutation at cytosine-containing pyrimidine dimers: studies of Escherichia coli B/r with acetophenone and 313-nm light.
We have tested the two-event model for UV mutagenesis producing class 2 suppressor mutations at glutamine tRNA genes in Escherichia coli. In the model used, the induction/indexing lesion is any type of pyrimidine dimer and the premutational photoproduct at the target site is a cytosine-containing dimer. Specific mutation-frequency responses were analyzed und
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22. Endonuclease-sensitive DNA modifications induced by acetone and acetophenone as photosensitizers.
Repair endonucleases, viz. endonuclease III, formamidopyrimidine-DNA glycosylase (FPG protein), endonuclease IV, exonuclease III and UV endonuclease, were used to analyse the modifications induced in bacteriophage PM2 DNA by 333 nm laser irradiation in the presence of acetone or acetophenone. In addition to pyrimidine dimers sensitive to UV endonuclease, 5,6
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23. Conversion of 4-Hydroxyacetophenone into 4-Phenyl Acetate by a Flavin Adenine Dinucleotide-Containing Baeyer-Villiger-Type Monooxygenase
An arylketone monooxygenase was purified from Pseudomonas putida JD1 by ion exchange and affinity chromatography. It had the characteristics of a Baeyer-Villiger-type monooxygenase and converted its substrate, 4-hydroxyacetophenone, into 4-hydroxyphenyl acetate with the consumption of one molecule of oxygen and oxidation of one molecule of NADPH per molecule
American Society for Microbiology.
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24. CD studies of conformational changes of DNA upon photosensitized UV-irradiation at 313 nm.
The role of thymine dimerization for previously reported U.V. induced conformational changes has been proved using acetophenone as sensitizer for the specific thymine dimerization upon irradiation at 313 nm. CD results demonstrate that formation of pyrimidine dimers cause typical conformational changes of the DNA B helix as observed on irradiation at 254 nm.