Monomethyl Phosphate Research Articles

ChemInform Abstract: Models for the Interaction of Zn2+ with DNA. Syntheses and X‐Ray Structural Characterizations of Two Polymeric Tetrahedral Zinc Complexes of Monomethyl Phosphate Esters of Cytidine and Deoxycytidine 5′‐Monophosphate Nucleotides.

AbstractThe both complexes (I) are prepared as previously described and investigated by single‐crystal X‐ray methods.

Models for the interaction of zinc(2+) with DNA. Syntheses and x-ray structural characterizations of two polymeric tetrahedral zinc complexes of monomethyl phosphate esters of cytidine and deoxycytidine 5'-monophosphate nucleotides

Models for the interaction of zinc(2+) with DNA. Syntheses and x-ray structural characterizations of two polymeric tetrahedral zinc complexes of monomethyl phosphate esters of cytidine and deoxycytidine 5'-monophosphate nucleotides

Distribution and degradation of tetrachlorvinphos on stored faba beans and soya beans

The distribution and degradation of [CH 3- 14C]tetrachlorvinphos in stored fabe beans and soya beans were studied for 30 weeks at moisture contents and temperatures similar to those prevailing under normal storage conditions. Tetrachlorvinphos penetrated the seed coat and the insecticide residues inside the beans increased with storage time. A considerable portion of radioactivity, amounting to about 20–30% of the applied dose in faba beans and 30–40% in soya beans, was present in a non-extractable form. Residues on the seed coat consisted mainly of unchanged insecticide. The internal extract contained both unchanged insecticide and desmethyltetrachlorvinphos which was present in a free and a conjugated form. Dimethyl phosphate and monomethyl phosphate were identified as hydrophilic 14C-degradation products. The degradation of tetrachlorvinphos proceeded mainly via cleavage of methoxy groups. The nature and percentage of metabolites varied slightly with storage period. A scheme for possible degradation routes of tetrachlorvinphos on stored beans is suggested.

Models for the interaction of zinc(2+) ion with DNA. The synthesis and x-ray structural characterization of two octahedral zinc complexes with monomethyl phosphate esters of 6-oxopurine 5'-monophosphate nucleotides

Models for the interaction of zinc(2+) ion with DNA. The synthesis and x-ray structural characterization of two octahedral zinc complexes with monomethyl phosphate esters of 6-oxopurine 5'-monophosphate nucleotides

Hydrolysis of organic and inorganic phosphorus compounds added to soils

The rates of hydrolysis of seven organic and two inorganic phosphorus compounds applied to soils at a rate of 500 ppm P and incubated at 20°C for various times under aerobic and waterlogged conditions were studied. Monomethyl phosphate, β-glycerophosphate, and α-D-glucose-1-phosphate were hydrolyzed at similar rates in the three soils used, but the rates were somewhat faster under aerobic than under waterlogged conditions. Organic P compounds in which two hydrogens of the orthophosphoric acid are replaced (e.g., diphenyl phosphate) were hydrolyzed at slower rates than those in which one hydrogen is replaced (e.g., phenyl phosphate). The rate of hydrolysis of diphenyl phosphate was lower than that of bis- p-nitrophenyl phosphate. Of the two inorganic P compounds studied, ammonium tetrametaphosphimate did not hydrolyze in soil, and the rate of hydrolysis of phosphonitrilic hexaamide was very small (6–13% hydrolyzed in 7 days) compared with those of the organic phosphates (30–98%).

Organische Phosphorverbindungen. XII [1]. Zum Hydrolyseverhalten von O,O‐Dimethyl‐O‐(1,2‐dibrom‐2,2‐dichlorethyl)‐phosphat (Naled)

Organic Phosphorus Compounds. XII. The Hydrolytic Behaviour of O,O‐Dimethyl O‐(1,2‐Dibromo‐2,2‐dichloroethyl) Phosphate (Naled)The hydrolysis of Naled 2, an organophosphorus pesticide accessible by bromination of the enolphosphate Dichlorvos 1, in unbuffered aqueous solution does not only lead — as hitherto described — to dimethyl phosphate 3 and bromodichloroacetaldehyde 4 (path A), but also via intermediate formation of Desmethylnaled 5 to monomethyl phosphate 6 (path B). Kinetic measurements show that in the temperature range of 20–30°C both reactions proceed with similar velocities, and the primary step 2 → 5 determines the rate of path B. In comparison to Dichlorvos 1 the hydrolytic stability of Naled 2 has been found to be markedly lower. — The information on the degradation of Naled in unbuffered aqueous solution is completed by studies on the pH‐dependence of the hydrolysis and on the alkylation capacity of this pesticide.

Kinetics of catalytic esterification of terephthalic acid with methanol vapour

This paper describes the investigations carried out on the kinetics of the solid-gas reaction between terephthalic acid and methyl alcohol in presence of phosphoric acid as the catalyst. As phosphoric acid itself reacts with the alcohol forming methyl phosphates, the kinetic data obtained have been analysed taking this reaction into account. The rate of formation of monomethyl phosphate has been found to be proportional to the square of the mole fraction of the acid present at any instant. The activation energy involved in this reaction is 11.3 kcal/g mole. The data obtained on terephthalic acid esterification show that; (i) the conversion sharply increases with an increase in the catalyst concentration between 30–35 per cent (w/w), (ii) the ‘shrinking particle’ model, proposed by Levenspiel for solid-gas reactions, can be conveniently adapted to represent the reaction, and (iii) the temperature dependency of the reaction follows the Arrhenius law, with activation energy being 11.5 kcal/g mole.

Glutathione-dependent degradation of 2,2 dichlorovinyl dimethyl phosphate (DDVP) by the rat

The present communication presents evidence showing that rat liver degrades 2,2-dichlorovinyl dimethyl phosphate (DDVP or Vapona) by two main enzymatic pathways. The first one produces 2,2 dichlorovinyl monomethyl phosphate (des-CH 3-DDVP) and it is glutathione- dependent. The second enzymatic system metabolizes DDVP to dimethyl phosphate and dichloroacetaldehyde and it is glutathione-independent. The degradation of des-CH 3-DDVP to dichloroacetaldehyde and monomethyl- phosphate is also glutathione-independent. The role of reduced-glutathione in the degradation of organophosphorous compounds is discussed.

Purificationof Flavin Mononucleotide-dependent Enzymes by Column Chromatography on Flavin Phosphate Cellulose Compounds

Abstract The chemical syntheses of mono- and dimethyl esters of riboflavin phosphate were accomplished by allowing riboflavin to react with the appropriate mono- and dimethylchlorophosphoric acids. Riboflavin monomethyl phosphate was found to be coenzymatically active with nicotinamide adenine dinucleotide phosphate-cytochrome c aporeductase, pyridoxine (or pyridoxamine) phosphate apooxidase, and glycolate apooxidase. Riboflavin phosphate esters of cellulose phosphate and diethylaminoethyl cellulose were prepared by reactions with riboflavin dichlorophosphate in pyridine; the corresponding derivative of cellulose was prepared by reaction with riboflavin phosphate and dicyclohexylcarbodiimide in pyridine. The riboflavin phosphate cellulose compounds were used to retain the riboflavin phosphate-dependent apoenzymes selectively during their chromatographic purification from extraneous protein. Extensive enrichment of glycolate apooxidase was achieved by chromatography on riboflavin phosphate cellulose.

Vibrational frequencies of phosphate derivatives

Tri-potassium phosphate, di-potassium monomethyl phosphate and lithium dimethyl phosphate have been found to be ideal model systems on which to base a vibrational analysis of the PO stretching modes in various orthophosphate salt derivatives. We find that a stretching mode which lies about 1200 cm −1 (<8·2 μ) can be used as a characteristic for disubstituted monobasic salts since the highest modes observed for dibasic derivatives lie below 1150 cm −1 ( >8·7 μ).

Intrasphärische und extrasphärische Komplexe mit Phosphatliganden. Infrarotspektren von Phosphatkomplexen in wässeriger Lösung

AbstractThe structures of complexes with ligands containing the PO32− group – monomethyl phosphate, diphosphate, monomethyl diphosphate and adenosine‐5′‐triphosphate – have been studied by infrared absorption measurements in aqueous solution.