Phosphonates
Mostrando 1-12 de 46 artigos, teses e dissertações.
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1. Síntese, caracterização e estudos biológicos de novas dialquilfosforilidrazonas derivadas de cetonas. / New Dialkylphosphorylydrazones: Synthesis, Characterization and Evaluation of Biological Activity. Seropédica, UFRRJ, 2007.
A series of twelve novel organophosphorus compounds, derived from dialkylphosphorylydrazone ketones were synthesized in three steps of reaction: the first step is the synthesis of various dialkyl phosphonates which are obtained by reaction of phosphorus trichloride (PCl3) with three Mols the corresponding alcohois. In the second step, the reaction of the dia
Publicado em: 2009
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2. Compostos organofosforados pentavalentes: histórico, métodos sintéticos de preparação e aplicações como inseticidas e agentes antitumorais
This paper is a review of the history, synthesis and application of organophosphorus compounds, especially of those of pentavalent phosphorus, such as phosphoramidates, phosphorothioates, phosphonates and phosphonic acids with insecticide and anticancer activities. The organophosphorus compounds with agrochemical applications show great structural variety, T
Química Nova. Publicado em: 2007-02
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3. Conformational analysis of ortho and meta-acetophenones α phosphonates and their derivatives substituted: α methylthio; α methylsulphinyl: and α methylsulphonyl and reactivity study of substituted ortho and meta α haloacetophenones with triethylphosphite / Análise conformacional de orto e meta-acetofenonas α -fosfonatos e seus derivados: α-metiltio; α:metilsulfinil; e α-metilsulfonil- substituídas e estudo da reatividade de α-haloacetofenonas orto e meta-substituídas com trietilfosfito
This thesis reports the study of the reactivity of the competitive Michaelis- Arbuzov and Perkow reactions of some orto- and meta- substituted α-haloacetophenones (I) [o- and m-Y-Φ-C(O)CH2-Hal] (Hal = CI, Br e I; Y = OMe, Me, H, F, CI, Br and NO2) with triethyl phosphite, by gas chromatography, and the conformational analysis of some orto- and meta-s
Publicado em: 2003
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4. Metil e fenilfosfonatos de calcio-sintese, caracterização, intercalação de aminas alifaticas e calorimetria
Calcium phosphonates Ca(HO3PR)2.xH2O (x = 1 or 2 R = CH3 or C6H5) were synthesized through reaction in aqueous media between calcium and phosphonic acids. The aim was to intercalate n-alkylamines: methyl -, ethyl -, propyl -, butyl -, pentyl and octylamines into Ca(HO3PC6H5)2.2H2O (CaPP1), Ca(HO3PCH3)2.H2O (CaPM) in aqueous media and the anhydrous Ca(HO3PC6H
Publicado em: 2000
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5. Synthesis of DNA via deoxynucleoside H-phosphonate intermediates.
Deoxynucleoside H-phosphonates are used in the chemical synthesis of deoxyoligonucleotides up to 107 bases in length. The biological activity of the synthetic DNA is assessed by cloning into M13 and sequencing. An improved synthesis of protected deoxynucleoside H-phosphonates is also described.
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6. Phosphonate utilization by bacterial cultures and enrichments from environmental samples.
A selection of axenic microbial strains and a variety of environmental samples were investigated with respect to the utilization of a series of natural and xenobiotic phosphonates as the sole phosphorus source for growth. Phosphonate degradation was observed only with bacteria and not with eucaryotic microorganisms. All representatives of the phosphonates ex
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7. Oligonucleotides with novel, cationic backbone substituents: aminoethylphosphonates.
Oligonucleotide (2-aminoethyl)phosphonates in which the backbone consisted of isomerically pure, alternating (2-aminoethyl)-phosphonate and phosphodiester linkages have been prepared and characterized. One of these single isomer oligonucleotides (Rp) formed a more stable duplex with DNA or RNA than its corresponding natural counterpart. Hybrid stability was
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8. A model study directed towards the preparation of nucleopeptides via H-phosphonate intermediates.
The monofunctional phosphitylating reagents bis-(N,N-diethylamino)chlorophosphine and salicylchlorophosphine have been applied for the preparation of H-phosphonates of the amino acids serine, threonine and tyrosine. Experimental evidence showed that the latter reagent was less effective for the synthesis of a tyrosine H-phosphonate. The amino acids (peptide)
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9. Rhizobium (Sinorhizobium) meliloti phn Genes: Characterization and Identification of Their Protein Products
In Escherichia coli, the phn operon encodes proteins responsible for the uptake and breakdown of phosphonates. The C-P (carbon-phosphorus) lyase enzyme encoded by this operon which catalyzes the cleavage of C-P bonds in phosphonates has been recalcitrant to biochemical characterization. To advance the understanding of this enzyme, we have cloned DNA from Rhi
American Society for Microbiology.
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10. Metabolism and in vitro antiretroviral activities of bis(pivaloyloxymethyl) prodrugs of acyclic nucleoside phosphonates.
Bis(pivaloyloxymethyl) [bis(pom)] derivatives of various acyclic nucleoside phosphonates--9-(2-phosphonylmethoxyethyl)adenine (PMEA), 9-(2-phosphonylmethoxypropyl)adenine (PMPA), and 9-(2-phosphonylmethoxypropyl)diaminopurine (PMPDAP)--were found to exhibit 9- to 23-fold greater antiviral activity than their corresponding unmodified compounds. The cytotoxici
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11. Antiretroviral activities of acyclic nucleoside phosphonates [9-(2-phosphonylmethoxyethyl)adenine, 9-(2-phosphonylmethoxyethyl)guanine, (R)-9-(2-phosphonylmethoxypropyl)adenine, and MDL 74,968] in cell cultures and murine sarcoma virus-infected newborn NMRI mice.
From a side-by-side comparative study, the acyclic nucleoside phosphonates (R)-9-(2-phosphonylmethoxypropyl)adenine [(R)-PMPA] and 9-(2-methylidene-3-phosphonomethoxypropyl)guanine (MDL 74,968) proved more selective in their inhibitory effect on human immunodeficiency virus types 1 and 2, feline immunodeficiency virus, and Moloney murine sarcoma virus (MSV)
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12. Characterization of the Rhizobium (Sinorhizobium) meliloti high- and low-affinity phosphate uptake systems.
Genetic studies have suggested that Rhizobium (Sinorhizobium) meliloti contains two distinct phosphate (Pi) transport systems, encoded by the phoCDET genes and the orfA-pit genes, respectively. Here we present data which show that the ABC-type PhoCDET system has a high affinity for Pi (Km, 0.2 microM) and that Pi uptake by this system is severely inhibited b