Azetidine
Mostrando 1-12 de 51 artigos, teses e dissertações.
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1. 3-azetidinonas e 3-azetidinois : preparação e aplicações na sintese de azetidinas substituidas / Azetidin-3-ones and Azetidin-3-ols: preparation and applications in the synthesis of substituted Azetidines
O trabalho de tese envolve a química de heterociclos de 4 membros, contendo um átomo de nitrogênio (azetidinas). Neste trabalho são apresentados 3 capítulos envolvendo 3-azetidinonas e 3-azetidinóis como principais intermediários para a síntese de azetidinas. No primeiro capítulo é demostrado o desenvolvimento de uma nova metodologia para a síntes
Publicado em: 2006
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2. Saccharomyces cerevisiae Σ1278b Has Novel Genes of the N-Acetyltransferase Gene Superfamily Required for l-Proline Analogue Resistance
We discovered on the chromosome of Saccharomyces cerevisiae Σ1278b novel genes involved in l-proline analogue l-azetidine-2-carboxylic acid resistance which are not present in the standard laboratory strains. The 5.4 kb-DNA fragment was cloned from the genomic library of the l-azetidine-2-carboxylic acid-resistant mutant derived from a cross between S. cere
American Society for Microbiology.
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3. Inhibition of Liver Fibrosis by L-Azetidine-2-Carboxylic Acid in Rats Treated with Carbon Tetrachloride
L-Azetidine-2-carboxylic acid (AZC), an analogue of proline, has been shown to partially ameliorate hepatic cirrhosis induced in rats by CCl4. AZC caused a diminution in formation of collagen in the liver accompanied by a relative decrease in the pool of free proline. The synthesis of noncollagenous proteins in the livers of treated rats did not appear to be
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4. Production of amino acids by analog-resistant mutants of the cyanobacterium Spirulina platensis.
Mutants of Spirulina platensis resistant to 5-fluorotryptophan, beta-3-thienyl-alanine, ethionine, p-fluorophenylalanine, or azetidine-2-carboxylic acid were isolated. Some of these mutants appeared to be resistant to more than one analog and to overproduce the corresponding amino acids. A second group was composed of mutants that were resistant to one analo
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5. Mechanism of Mengo Virus-Induced Cell Injury in L Cells: Use of Inhibitors of Protein Synthesis to Dissociate Virus-Specific Events
L cells were infected with Mengo virus in the presence of varying concentrations of protein synthesis inhibitors (azetidine-2-carboxylic acid, p-fluorophenylalanine, puromycin), and examined with respect to the effects of the inhibitors on several features of virus-induced cell injury. The virus-specific events in the cells could be dissociated into three gr
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6. Crystallization and preliminary crystallographic analysis of N-acetyltransferase Mpr1 from Saccharomyces cerevisiae
The yeast N-acetyltransferase that N-acetylates l-azetidine-2-carboxylic acid has been crystallized. Native data were collected to 1.9 Å resolution from a substrate-soaked crystal.
International Union of Crystallography.
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7. Incorporation of Label from 13C-, 2H-, and 15N-Labeled Methionine Molecules during the Biosynthesis of 2[prime]-Deoxymugineic Acid in Roots of Wheat.
The biosynthetic pathway of 2[prime]-deoxymugineic acid, a key phytosiderophore, was investigated by feeding 13C-, 2H-, and 15N-labeled methionine, the first precursor, to the roots of hydroponically cultured wheat (Triticum aestivum L. cv Minori). The incorporation of label from each methionine species was observed during their conversion to 2[prime]-deoxym
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8. Effect of Azetidine 2-Carboxylic Acid on Ion Uptake and Ion Release to the Xylem of Excised Barley Roots 1
Azetidine 2-carboxylic acid (AZ) was used as an analog of proline to investigate further the relationship between protein synthesis and ion transport. AZ does not inhibit protein assembly, but the proteins formed are ineffective as enzymes. At relatively low concentrations (50 μM) AZ was a potent inhibitor of release of ions to the xylem of excised roots of
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9. Effects of Proline Analogues on the Formation of Alkaline Phosphatase in Escherichia coli
Two of the four proline analogues tested for their effect on the formation and activity of Escherichia coli alkaline phosphatase were able to substitute for proline in protein synthesis in a proline auxotroph. One of these, 3,4-dehydroproline, effectively replaced proline and led to formation of an active enzyme under conditions where no proline was present
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10. Production, Isolation, and Properties of Azetomycins
Streptomyces antibioticus synthesizes five actinomycins that differ in the “proline site” of the molecule. When cultured in the presence of azetidine-2-carboxylic acid (AzC), antibiotic synthesis was stimulated 40 to 50%, synthesis of actinomycin IV was inhibited, and one or both prolines were replaced by AzC. AzC incorporation could not be reversed by c
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11. Adenine photodimerization in deoxyadenylate sequences: elucidation of the mechanism through structural studies of a major d(ApA) photoproduct.
The mechanism of the photodimerization of adjacent adenine bases on the same strand of DNA has been elucidated by determining the structure of one of the two major photoproducts that are formed by UV irradiation of the deoxydinucleoside monophosphate d(ApA). The photoproduct, denoted d(ApA)*, corresponds to a species of adenine photodimer first described by
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12. Intracellular localization of a group II chaperonin indicates a membrane-related function
Chaperonins are protein complexes that are believed to function as part of a protein folding system in the cytoplasm of the cell. We observed, however, that the group II chaperonins known as rosettasomes in the hyperthermophilic archaeon Sulfolobus shibatae, are not cytoplasmic but membrane associated. This association was observed in cultures grown at 60°C
National Academy of Sciences.