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PubMed1985

Metabolism of phosphorus-containing compounds by pig liver microsomal FAD-containing monooxygenase.

Oxidative desulfuration of phosphonate insecticides such as fonofos (S-phenyl ethyl ethylphosphonodithioate) and its analogs is catalyzed by pig liver microsomal FAD-containing monooxygenase, although desulfuration of phosphorodithioates, such as parathion, is not. Substitution of an alkyl group for the remaining alkoxy group, as in S-phenyl diethylphosphinodithioate, did not increase its oxidation rate. Diethylphenylphosphine sulfide, containing 3 phosphorus-carbon bonds, was actually a poorer substrate than fonofos. Replacement of the S-phenyl group of fonofos with an O-phenyl group increased the Km value above the solubility limit. Trivalent phosphorus-containing compounds were also excellent substrates for this enzyme. Diethylphenylphosphine had a Km value lower than 2.5 microM. Diethyl phenylphosphonite also appeared to be an excellent substrate but its rapid nonenzymatic hydrolysis and/or oxidation precluded accurate Km determinations. Stoichiometry studies with diethylphenylphosphine and its sulfide showed that O2 and NADPH consumption were approximately equal to the substrate consumed. The major metabolite of both diethylphenylphosphine and its sulfide was the phosphine oxide. These results show that microsomal FAD-containing monooxygenase of pig liver has activity as a phosphorus-oxidase, in addition to its well characterized nitrogen- and sulfur-oxidase roles.

Animals↗
PubMed1975

The action of staphylococcal nuclease (EC-number 3. 1. 4. 7.) on thymus nucleohistone (TNH) and on some nucleoprotamines.

The biphasic nature of the time course of the action of staphylococcal nuclease on thymus nucleohistone was confirmed by studying the hydrolysis of this nucleoprotein at various enzyme concentrations. The transition from the rapid first to the sluggish second phase of the time course was particularly distinct at the highest enzyme concentrations. The rapid initial phase of the hydrolysis curve leveled off sharply when between 60 and 65 per cent of the total TNH phosphorus had been converted to acid-soluble phosphorus compounds. The insoluble complexes of TNH with protamines were found to be very resistant against the action of staphylococcal nuclease. The time course of the action of staphylococcal nuclease on a commercial nucleoprotamine of salmon testicles was found to become very sluggish when between 35 and 40 per cent of its total phosphorus had been converted to acid-soluble phosphorus compounds. When nucleoprotamines prepared in the laboratory from the secreted sperm cell suspension of Brown Brook Trout were digested with staphylococcal nuclease, only between 15 and 20 per cent of the total phosphorus were cleaved to acid-soluble phosphorus compounds during the rapid phase of the nuclease action. The respective values for the phosphorus fractions available for magnesium-binding and those susceptible to the rapid cleavage by staphylococcal nuclease were found to be very similar.

Animals↗
PubMed1996

Hexacoordinate Phosphorus. 7. Synthesis and Characterization of Neutral Phosphorus(V) Compounds Containing Divalent Tridentate Diphenol Imine, Azo, and Thio Ligands.

The reactions of bis(trimethylsilyl)ated forms of the Schiff base ligands N-(2-hydroxyphenyl)salicylideneamine {(HO)C(6)H(4)N(CH)C(6)H(4)(OH)}, N-(4-tert-butyl-2-hydroxyphenyl)salicylideneamine {(HO)((t)Bu)C(6)H(3)N(CH)C(6)H(4)(OH)}, N-(2-hydroxy-4-nitrophenyl)salicylideneamine {(HO)(O(2)N)C(6)H(3)N(CH)C(6)H(4)(OH)}, and the structurally related ligand 2,2'-azophenol with halogeno- and (trifluoromethyl)halogenophosphoranes yield a series of neutral hexacoordinate phosphorus(V) compounds by means of trimethylsilyl halide elimination. In all of these cases the ligands chelate in a meridional conformation in which bicyclic five- and six-membered chelate rings are formed through structures containing two phenolic P-O bonds and one N-P bond. The hexacoordinate nature of these compounds is evidenced by their high-field (31)P NMR chemical shifts and their characteristic J(PF) coupling patterns and is further substantiated by the crystal structures of {O((t)Bu)C(6)H(3)N(CH)C(6)H(4)O}PCl(3) and {OC(6)H(4)N=NC(6)H(4)O}PF(3). Crystal data for {O((t)Bu)C(6)H(3)N(CH)C(6)H(4)O}PCl(3): triclinic, space group P&onemacr; (No. 2), a = 11.167(1) Å, b = 15.684(1) Å, c = 17.047(2) Å, V = 2840(1) Å(3), Z = 2. Final R and R(w) values were 0.051 and 0.079, respectively. Crystal data for {OC(6)H(4)N=NC(6)H(4)O}PF(3): monoclinic, space group P2(1)/c (No. 14), a = 6.9393(8) Å, b = 12.450(2) Å, c = 13.907(2) Å, V = 1190.7(6) Å(3), Z = 4. Final R and R(w) values were 0.045 and 0.056, respectively. The molecular structures of {O((t)Bu)C(6)H(3)N(CH)C(6)H(4)O}PCl(3) and {OC(6)H(4)N=NC(6)H(4)O}PF(3) show that in both cases the Schiff base ligand chelates occupy the meridional plane about the six-coordinate phosphorus atom. In the case of {OC(6)H(4)N=NC(6)H(4)O}PF(3) the equivalent nitrogen atoms in the chelate rings are disordered to form half-occupancy pairs. The silylated form of the related thiobis(phenol), 2,2'-thiobis(4,6-tert-butylphenol), reacted similarly with pentavalent halides to form the six-coordinate complex [{2-O-3,5-((t)Bu)(2)C(6)H(2)}(2)S]PCl(3) which was also verified by a crystal structure. Crystal data for [{2-O-3,5-((t)Bu)(2)C(6)H(2)}(2)S]PCl(3): monoclinic P2(1)/n, a = 13.989(2), b = 13.594(2), c = 16.483(2) Å, beta = 97.98(2) degrees, V = 3104(2) Å(3), Z = 4; final R and R(w)() values were 0.039 and 0.052, respectively. In contrast to the above six coordinate complexes, this compound possesses a facial structure in which two phenoxy substituents form planar chelates centered on the bridging sulfur and intersecting at the P-S axis. The P-S bond length, 2.331(1) Å, is slightly shorter than has been previously observed in the example wherein the ligand possesses two tert-butyl groups and the phosphorus carries three OCH(2)CF(3 )substituents indicating stronger interaction between P and S in the present case.

Journal Article↗
PubMed2003

Disposal of spent tributylphosphate by gliding arc plasma.

The gliding arc in humid air is a relevant source of free radicals and strongly oxidising species such as HO* (shown by emission spectroscopy), which are able to degrade organic wastes. This feature was used in a new process for mineralising spent tributylphosphate (TBP) which is an important waste from nuclear industry. The degradation kinetics is examined by monitoring the conversion of TBP into phosphoric acid in a batch reactor. The kinetics exhibits three steps and especially an overall zero-order linear step with a rate of 10 mmol h(-1) at the beginning of the treatment. This zero-order step agrees with a surface oxidation process. After a 13.7h treatment, about 45% of the TBP is converted into inorganic phosphorus compounds, with phosphoric acid as the major product (63% of inorganic phosphorus compounds), and at least 19.5% is not degraded. Dibutylphosphoric acid (HDBP) was identified as the main by-product by a nuclear magnetic resonance technique, infrared spectroscopy and gas chromatography.

Free Radicals↗
PubMed1993

Induction of a 70-kDa protein in human lymphocytes exposed to inorganic heavy metals and toxic organic compounds.

Human peripheral blood lymphocytes synthesize a 70-kDa protein (p70) distinct from metallothionein (MT), in response to several inorganic heavy metals. Although Cd and Zn induce both p70 and MTs, Co induces only p70. On the other hand, Cu, Hg, Ni and Ag, which are the inducers of MTs, can not induce p70. This protein is indistinguishable in electrophoretic mobility from the 70-kDa heat shock protein, which is induced by incubation of lymphocytes at 42-45 degrees C. Several environmental pollutants other than the inorganic heavy metals, including organic tin compounds and organic phosphorus compounds, were also found to induce p70. The responsiveness to a variety of environmental stimuli suggests the involvement of p70 in the basic cellular defense mechanism.

Blood Proteins↗
PubMed2006

Structural investigations of phosphorus-nitrogen compounds. 7. Relationships between physical properties, electron densities, reaction mechanisms and hydrogen-bonding motifs of N3P3Cl(6 - n)(NHBu(t))n derivatives.

A series of compounds of the N3P3Cl(6 - n)(NHBu(t))n family (where n = 0, 1, 2, 4 and 6) are presented, and their molecular parameters are related to trends in physical properties, which provides insight into a potential reaction mechanism for nucleophilic substitution. The crystal structures of N3P3Cl5(NHBu(t)) and N3P3Cl2(NHBu(t))4 have been determined at 120 K, and those of N3P3Cl6 and N3P3Cl4(NHBu(t))2 have been redetermined at 120 K. These are compared with the known structure of N3P3(NHBu(t))6 studied at 150 K. Trends in molecular parameters [phosphazene ring, P-Cl and P-N(HBu(t)) distances, PCl2 angles, and endo- and exocyclic phosphazene ring parameters] across the series are observed. Hydrogen-bonding motifs are identified, characterized and compared. Both the molecular and the hydrogen-bonding parameters are related to the electron distribution in bonds and the derived basicities of the cyclophosphazene series of compounds. These findings provide evidence for a proposed mechanism for nucleophilic substitution at a phosphorus site bearing a PCl(NHBu(t)) group.

Journal Article↗
PubMedDate not supplied

[Species composition and biochemical properties of yeasts from the water of the Bratsk reservoir].

The specific composition of 370 yeast strains isolated from the water of the Bratsk Reservoir was studied. The strains were assigned to 7 genera and 16 species according to their morphological, cultural, and physiologo-biochemical properties. Asporogenous forms prevailed; 52 strains possessed the amylolytic activity. The proteolytic activity was found in the cultures very seldom. The capability to assimilate organic phosphorus compounds was detected in 8% of the strains, and the ability to use inorganic phosphorus compounds was registered in 38% of the strains. Up to 95% of the strains utilized oil; 88%--engine oil; 43%--phenol. The specific yeast composition varied depending on the biotype.

Candida↗
PubMed1977

Chloro compounds of phosphorus as industrial hazards.

The toxicometric indices of phosphorus oxychloride, trichloride and pentachloride were determined and the peculiarities of the toxic effect of these compounds were investigated in experiment. Comparative characteristics of the irritant and resorptive effects of the substances were presented. The highest admissible concentrations (HAC) in the air of the working place were set at 0.05 mg/m3, 0.2 mg/m3 and 0.2 mg/m3 for phosphorus oxychloride, phosphorus trichloride and phosphorus pentachloride, respectively. Some prophylactic measures were recommended.

Animals↗
PubMed1985

Phosphorus-nitrogen compounds. 26. Phosphaminimides. 2. 2,2'-Phosphinylidenebis(1,1,1-trimethylhydrazinium) iodide inner salts as agents affecting ganglionic transmission.

The N-2 atoms of phosphorus 2,2-dimethylhydrazides, contrary to a previous report, can be methylated by iodomethane. Treatment of the resulting dihydrazinium iodides with aqueous sodium hydroxide results in mono- instead of didehydroiodination, apparently due to resonance stabilization of the inner salt form. The phosphaminimide products and their hydrazinium iodide precursors blocked sympathetic ganglionic transmission while one dihydrazide intermediate produced potentiation. Brine shrimp testing indicated that conversion of a hydrazinium iodide to an aminimide moiety results in decreased toxicity.

Animals↗
PubMed1988

Phosphorus nuclear magnetic resonance in isolated perfused rat pancreas.

Phosphorus nuclear magnetic resonance spectroscopy was applied to measure phosphorus energy metabolites in isolated perfused rat pancreas. The gland was perfused with a modified Krebs-Henseleit solution at room temperature (25 degrees C). 31P resonances of creatine phosphate (PCr), ATP, ADP, inorganic phosphate (Pi), and phosphomonoesters (PMEs) were observed in all the preparations of pancreas. In different individual preparations, the resonance of PCr varied, but those of ATP were almost the same. The initial levels of PCr and ATP in individual preparations, however, remained almost unchanged during perfusion with the standard solution for 2 h. When the perfusion was stopped, the levels of ATP and PCr decreased, while the levels of PME and Pi increased. At that time, the Pi resonance shifted to a higher magnetic field, indicating that the tissue pH decreased. On reperfusion, the tissue levels of phosphorus compounds and the tissue pH were restored to their initial resting levels. Continuous infusion of 0.1 microM acetylcholine caused marked and sustained increases in the flow of pancreatic juice and protein output. During the stimulation the tissue levels of phosphorus compounds remained unchanged, while the tissue pH was decreased slightly (0.05 pH unit).

Adenine Nucleotides↗
PubMed2002

Inositol phosphates in the environment.

The inositol phosphates are a group of organic phosphorus compounds found widely in the natural environment, but that represent the greatest gap in our understanding of the global phosphorus cycle. They exist as inositols in various states of phosphorylation (bound to between one and six phosphate groups) and isomeric forms (e.g. myo, D-chiro, scyllo, neo), although myo-inositol hexakisphosphate is by far the most prevalent form in nature. In terrestrial environments, inositol phosphates are principally derived from plants and accumulate in soils to become the dominant class of organic phosphorus compounds. Inositol phosphates are also present in large amounts in aquatic environments, where they may contribute to eutrophication. Despite the prevalence of inositol phosphates in the environment, their cycling, mobility and bioavailability are poorly understood. This is largely related to analytical difficulties associated with the extraction, separation and detection of inositol phosphates in environmental samples. This review summarizes the current knowledge of inositol phosphates in the environment and the analytical techniques currently available for their detection in environmental samples. Recent advances in technology, such as the development of suitable chromatographic and capillary electrophoresis separation techniques, should help to elucidate some of the more pertinent questions regarding inositol phosphates in the natural environment.

Agriculture↗