Phosphorus-oxygen Bonds Research Articles

Revealing the binding properties between resorcinol and DNA

Resorcinol (1,3-dihydroxybenzene) is a common coupling agent in permanent hair dyes, and has arrested people's attention for its potential hazard to human health. However, the action mechanism of resorcinol and human DNA has not been elucidated. In this research, the binding properties between resorcinol and calf thymus DNA (ct-DNA) were studied for the first time through various spectral and molecular docking techniques. Spectral studies showed that the initial fluorescence quenching of resorcinol against DNA was a static one. The result of ΔH < 0 and ΔS > 0 was produced from thermodynamic experimental data, therefore it could be concluded that electrostatic force was the major driving force, while binding constant Kb was 1.56 × 104 M-1 at 298 K. The electrostatic binding network between resorcinol and ct-DNA was established explicitly through competitive substitution analysis and other spectral approaches. The results of FT-IR absorption spectra indicated that resorcinol had bound to the DNA phosphate skeleton. Molecular docking clearly revealed that binding occurred between hydroxyl groups of resorcinol and phosphorus oxygen bonds (P-O) of the DNA skeleton. These findings may deepen our understanding of the action mechanism between resorcinol and ct-DNA and provide some useful data on the effect of resorcinol on human diseases.

Fate of Liposomes in the Presence of Phospholipase C and D: From Atomic to Supramolecular Lipid Arrangement

Understanding the origins of lipid membrane bilayer rearrangement in response to external stimuli is an essential component of cell biology and the bottom-up design of liposomes for biomedical applications. The enzymes phospholipase C and D (PLC and PLD) both cleave the phosphorus–oxygen bonds of phosphate esters in phosphatidylcholine (PC) lipids. The atomic position of this hydrolysis reaction has huge implications for the stability of PC-containing self-assembled structures, such as the cell wall and lipid-based vesicle drug delivery vectors. While PLC converts PC to diacylglycerol (DAG), the interaction of PC with PLD produces phosphatidic acid (PA). Here we present a combination of small-angle scattering data and all-atom molecular dynamics simulations, providing insights into the effects of atomic-scale reorganization on the supramolecular assembly of PC membrane bilayers upon enzyme-mediated incorporation of DAG or PA. We observed that PC liposomes completely disintegrate in the presence of PLC, as conversion of PC to DAG progresses. At lower concentrations, DAG molecules within fluid PC bilayers form hydrogen bonds with backbone carbonyl oxygens in neighboring PC molecules and burrow into the hydrophobic region. This leads initially to membrane thinning followed by a swelling of the lamellar phase with increased DAG. At higher DAG concentrations, localized membrane tension causes a change in lipid phase from lamellar to the hexagonal and micellar cubic phases. Molecular dynamics simulations show that this destabilization is also caused in part by the decreased ability of DAG-containing PC membranes to coordinate sodium ions. Conversely, PLD-treated PC liposomes remain stable up to extremely high conversions to PA. Here, the negatively charged PA headgroup attracts significant amounts of sodium ions from the bulk solution to the membrane surface, leading to a swelling of the coordinated water layer. These findings are a vital step toward a fundamental understanding of the degradation behavior of PC lipid membranes in the presence of these clinically relevant enzymes, and toward the rational design of diagnostic and drug delivery technologies for phospholipase-dysregulation-based diseases.

Hydrofluoric Acid-Based Derivatization Strategy To Profile PARP-1 ADP-Ribosylation by LC-MS/MS.

Despite significant advances in the development of mass spectrometry-based methods for the identification of protein ADP-ribosylation, current protocols suffer from several drawbacks that preclude their widespread applicability. Given the intrinsic heterogeneous nature of poly(ADP-ribose), a number of strategies have been developed to generate simple derivatives for effective interrogation of protein databases and site-specific localization of the modified residues. Currently, the generation of spectral signatures indicative of ADP-ribosylation rely on chemical or enzymatic conversion of the modification to a single mass increment. Still, limitations arise from the lability of the poly(ADP-ribose) remnant during tandem mass spectrometry, the varying susceptibilities of different ADP-ribose-protein bonds to chemical hydrolysis, or the context dependence of enzyme-catalyzed reactions. Here, we present a chemical-based derivatization method applicable to the confident identification of site-specific ADP-ribosylation by conventional mass spectrometry on any targeted amino acid residue. Using PARP-1 as a model protein, we report that treatment of ADP-ribosylated peptides with hydrofluoric acid generates a specific +132 Da mass signature that corresponds to the decomposition of mono- and poly(ADP-ribosylated) peptides into ribose adducts as a consequence of the cleavage of the phosphorus-oxygen bonds.

Pulling on bonds counterintuitively

Mechanochemistry Experimental mechanochemistry has largely focused on the application of force along chemical bonds to accelerate their cleavage. Akbulatov et al. now demonstrate that force can also play a more subtle role. They generated strained macrocyclic rings photochemically and then studied the influence of that strain on the rates of reactions that cleaved either phosphorus-oxygen or silicon-oxygen bonds. P–O cleavage was accelerated by force orthogonal to the bond axis, whereas the Si–O cleavage was inhibited by force along the bond. Both results were consistent with the respective transition states predicted by theory. Science , this issue p. [299][1] [1]: /lookup/doi/10.1126/science.aan1026

Stereoselective PCO/POC-Rearrangement of P–C-Cage Phosphorane in the Reaction of 4,5-Dimethyl-2-(2-oxo-1,2-diphenyl)ethoxy-1,3,2-dioxaphospholane with Hexafluoroacetone

Interaction of 4,5-dimethyl-2-(2-oxo-1,2-diphenyl)ethoxy-1,3,2-dioxaphospholane, bearing a carboxyl group in the γ-position with respect to the phosphorus atom and obtained from d,l-butanediol, with hexafluoroacetone (CCl4, -40 °C) leads to the simultaneous formation of regio- and stereoisomeric cage-like phosphoranes with phosphorus-carbon and phosphorus-oxygen bonds with a high stereoselectivity (>95%), whose structure was determined by 1D and 2D NMR spectroscopy and XRD. When stored as a solution in dichloromethane for one month, the PCO-isomer rearranges into the thermodynamically more stable POC-isomer of the cage-like phosphorane. Mild hydrolysis of the PCO/POC-isomers proceeds with a high chemoselectivity and leads to the formation of P(IV)-dioxaphospholane derivatives. Acidic hydrolysis of the POC-isomer leads to the formation of an oxirane derivative with an unexpectedly high stereoselectivity (>95%). DFT calculations (using the PBE functional) allowed us to obtain structures and energies of the initial phospholane, reaction products (PCO/POC-isomers), and an intermediate P(V)-oxaphosphirane.

Interrogation of the Substrate Profile and Catalytic Properties of the Phosphotriesterase from Sphingobium sp. Strain TCM1: An Enzyme Capable of Hydrolyzing Organophosphate Flame Retardants and Plasticizers.

The most familiar organophosphorus compounds are the neurotoxic insecticides and nerve agents. A related group of organophosphorus compounds, the phosphotriester plasticizers and flame retardants, has recently become widely used. Unlike the neurotoxic phosphotriesters, the plasticizers and flame retardants lack an easily hydrolyzable bond. While the hydrolysis of the neurotoxic organophosphates by phosphotriesterase enzymes is well-known, the lack of a labile bond in the flame retardants and plasticizers renders them inert to typical phosphotriesterases. A phosphotriesterase from Sphingobium sp. strain TCM1 (Sb-PTE) has recently been reported to catalyze the hydrolysis of organophosphorus flame retardants. This enzyme has now been expressed in Escherichia coli, and the activity with a wide variety of organophosphorus substrates has been characterized and compared to the activity of the well-known phosphotriesterase from Pseudomonas diminuta (Pd-PTE). Structure prediction suggests that Sb-PTE has a β-propeller fold, and homology modeling has identified a potential mononuclear manganese binding site. Sb-PTE exhibits catalytic activity against typical phosphotriesterase substrates such as paraoxon, but unlike Pd-PTE, Sb-PTE is also able to effectively hydrolyze flame retardants, plasticizers, and industrial solvents. Sb-PTE can hydrolyze both phosphorus-oxygen bonds and phosphorus-sulfur bonds, but not phosphorus-nitrogen bonds. The best substrate for Sb-PTE is the flame retardant triphenyl phosphate with a kcat/Km of 1.7 × 10(6) M(-1) s(-1). Quite remarkably, Sb-PTE is also able to hydrolyze phosphotriesters with simple alcohol leaving groups such as tributyl phosphate (kcat/Km = 40 M(-1) s(-1)), suggesting that this enzyme could be useful for the bioremediation of a wide variety of organophosphorus compounds.

Reaction of 4,5-dimethyl-2-(2-oxo-1,2-diphenylethoxy)-1,3,2-dioxaphospholane with hexafluoroacetone: formation of isomeric caged phosphoranes with phosphorus–carbon and phosphorus–oxygen bonds

4,5-Dimethyl-2-(2-oxo-1,2-diphenylethoxy)-1,3,2-dioxaphospholane bearing the carbonyl group at the γ-position to the phosphorus atom reacted with hexafluoroacetone to give regio- and stereoisomeric caged phosphoranes with phosphorus–carbon and phosphorus–oxygen bonds.

Spectral Investigation of Phosphorus Compounds in Spinacia Oleracea Using Fourier Transform Infrared Method

The study uses the Fourier transform infrared spectroscopy method to evaluate the influence of phosphogypsum from the soil on the growth and accumulation of nutrients in Spinacia oleracea. Attenuated total reflectance spectra of Spinacia oleracea roots and stems originated from plants cultivated on 28% to 52% phosphogypsum enriched soil have been studied in the 4000–600 cm−1 area. The structure of the infrared absorption bands for spinach roots and stems and for the soil where plants were grown was analyzed. Thus, it was observed that phosphorus–oxygen bonds contribution can be identified both in roots and stems absorption spectra. The significance of the research is the possibility to use the infrared investigation as rapid technique, particularly useful for agriculture, to study the extraction and assimilation process of the compounds containing phosphorus and nitrogen from the soil in which the spinach seedlings grew. In the case of this study, it was observed that the absorption of phosphorus in the spinach roots and stems has not the same effect. The analysis of obtained data indicated that the assimilation of phosphorus from phosphogypsum enriched soil induces changes in spinach roots structure that are most likely due to an increase synthesis of proteins, rather than to a decrease in carbohydrates quantity.

Phosphinate Chemistry in the 21st Century: A Viable Alternative to the Use of Phosphorus Trichloride in Organophosphorus Synthesis.

Organophosphorus compounds are important in everyday applications ranging from agriculture to medicine and are used in flame retardants and other materials. Although organophosphorus chemistry is known as a mature and specialized area, researchers would like to develop new methods for synthesizing organophosphorus compounds to improve the safety and sustainability of these chemical processes. The vast majority of compounds that contain a phosphorus-carbon bond are manufactured using phosphorus trichloride (PCl3) as an intermediate. However, these reactions require chlorine, and researchers would like to avoid the use of PCl3 and develop safer chemistry that also decreases energy consumption and minimizes waste. Researchers have already proposed and discussed two primary strategies based on elemental phosphorus (P4 or Pred) or on phosphine (PH3) as alternatives to PCl3. However, phosphinates, an important class of phosphorus compounds defined as any compound with a phosphorus atom attached to two oxygens, R(1)R(2)P(O)(OR) (R(1)/R(2) = hydrogen/carbon), offer another option. This Account discusses the previously neglected potential of these phosphinates as replacements of PCl3 for the preparation of organophosphorus compounds. Because of their strong reductive properties, industry currently uses the simplest members of this class of compounds, hypophosphites, for one major application: electroless plating. In comparison with other proposed PCl3 surrogates, hypophosphorous derivatives can offer improved stability, lower toxicity, higher solubility, and increased atom economy. When their reducing power is harnessed to form phosphorus-carbon or phosphorus-oxygen bonds, these compounds are also rich and versatile precursors to organophosphorus compounds. This Account examines the use of transition metal-catalyzed reactions such as cross-coupling and hydrophosphinylation for phosphorus-carbon bond formation. Because the most important industrial organophosphorus compounds include compounds triply or quadruply bound to oxygen, I also discuss controlled transfer hydrogenation for phosphorus-oxygen bond formation. I hope that this Account will further promote research in this novel and exciting yet much underdeveloped area of phosphinate activation.

Phosphazene-Based Host Materials for the Use in Blue Phosphorescent Organic Light-Emitting Diodes

We present a series of low-molecular-weight materials based on cyclic phosphazenes for the use as host materials in blue phosphorescent organic light-emitting diodes. Substituted phenyl rings are attached to the central phosphazene ring either via phosphorus–oxygen bonds to yield phenoxy-substituted derivatives or via direct phosphorus–carbon bonds to yield phenyl-substituted derivatives. The phenoxy substituted cyclic phosphazenes were prepared by nucleophilic substitution of the six chlorine atoms in hexachlorocyclotriphosphazene with phenoxy groups, whereas the phenyl substituted cyclic phosphazenes were formed in a cyclocondensation reaction of three equivalents of substituted phosphinic amides. The phenyl substitution leads to materials with superior thermal properties compared to the phenoxy substitution. Because of the nonconjugated linkage to the phosphazene core, the host materials have very high triplet energies of more than 3 eV. In an OLED device using one compound as host for the saturated bl...

Investigation of the local structure of LiPON thin films to better understand the role of nitrogen on their performance

Amorphous thin solid films of lithium phosphorus oxynitride (LiPON) were prepared by radio-frequency sputtering from a Li 3PO 4 target by varying nitrogen flow rate. The aim of this study is to establish the correlations between deposition conditions, composition, local structure and the electrical properties of the electrolyte (ionic conductivity and activation energy). As expected, ionic conductivity of LiPON thin films increases with nitrogen flow rate reaching a maximum of 3.10 −6 S cm −1 while the activation energy reaches a minimum of 0.57 eV. The use of three complementary techniques, X-ray photoelectron spectroscopy, Raman spectroscopy and Nuclear Magnetic Resonance has allowed a thorough investigation of the local structure of the LiPON thin films. The formation of phosphorus–nitrogen bonds in place of phosphorus–oxygen bonds involves two kinds of nitrogen atoms (N1: a nitrogen atom linked to two phosphorus atoms (–N=), and N2: a nitrogen atom linked to three phosphorus atoms (–N<). The substitution of oxygen by nitrogen induces a decrease of the bridging oxygen/non-bridging oxygen ratio. This modification of the local structure favours lithium-ion mobility at the origin of the conductivity improvement.

Phosphate ester hydrolysis of biologically relevant molecules by cerium oxide nanoparticles

In an effort to characterize the interaction of cerium oxide nanoparticles (CNPs) in biological systems, we explored the reactivity of CNPs with the phosphate ester bonds of p-nitrophenylphosphate (pNPP), ATP, o-phospho- l-tyrosine, and DNA. The activity of the bond cleavage for pNPP at pH 7 is calculated to be 0.860 ± 0.010 nmol p-nitrophenol/min/μg CNPs. Interestingly, when CNPs bind to plasmid DNA, no cleavage products are detected. While cerium(IV) complexes generally exhibit the ability to break phosphorus-oxygen bonds, the reactions we report appear to be dependent on the availability of cerium(III) sites, not cerium(IV) sites. We investigated the dephosphorylation mechanism from the first principles and find the reaction proceeds through inversion of the phosphate group similar to an S N2 mechanism. The ability of CNPs to interact with phosphate ester bonds of biologically relevant molecules has important implications for their use as potential therapeutics. From the Clinical Editor The ability of cerium oxide nanoparticles to interact with phosphate ester bonds of biologically relevant molecules has important implications for their use as potential therapeutics. This team of investigators explored the reactivity of these nanoparticles with the phosphate ester bonds of p-nitrophenylphosphate, ATP, o-phospho-L-tyrosine, and DNA.

Correlation between Raman wavenumbers and P?O bond lengths in crystalline inorganic phosphates

A linear empirical correlation was established between Raman stretching wavenumbers of phosphorus–oxygen bonds and their bond lengths in inorganic crystalline phosphates. Although established on samples of inorganic crystalline phosphates, the correlation can be applied to glassy and amorphous phosphate materials (GAMs). Their unpolarized vibrational spectra are often similar because they are determined largely by short-range order. The correlation was used to predict PO bond length in the α-form of Li3PO4, which is stable over only a small range of temperatures below the melting-point. It can also be used to estimate the length of PO single bonds, terminal PO and OPO chain bonds and terminal double bonds in many technologically important amorphous materials containing phosphate groups. This correlation is expected to offer invaluable insight into the structures of phosphate species for which diffraction or other spectroscopic techniques provide incomplete structural information. That would enhance the value of Raman spectroscopy as a complementary technique in structural studies of phosphates. Copyright © 2004 John Wiley & Sons, Ltd.

Solution and solid state structural investigations of organotin(IV) compounds containing asymmetric imidodiphosphinato ligands. X-ray structures of R′′ 2Sn[(OPMe 2)(OPPh 2)N] 2 (R=Me, Bu n, Ph)

Organotin(IV) derivatives of the type R 2Sn[(OPMe 2)(OPPh 2)N] 2 (R=Me, Bu n , Bz, Ph) were prepared by metathesis reactions between R 2SnCl 2 and the potassium salt of the imidodiphosphinic acid, in toluene. Me 3SnCl and K[(OPMe 2)(OPPh 2)N] (1:1 molar ratio) in chloroform at room temperature gives Me 3Sn[(OPMe 2)(OPPh 2)N], while the NMR studies indicate that the corresponding triphenyltin(IV) derivative disproportionates gradually in solution to give Ph 2Sn[(OPMe 2)(OPPh 2)N] 2. Attempts to grow crystals of the trimethyltin(IV) derivative also gives Me 2Sn[(OPMe 2)(OPPh 2)N] 2 as a redistribution product. The compounds were characterized by IR and multinuclear NMR spectroscopy. The crystal and molecular structures of R 2Sn[(OPMe 2)(OPPh 2)N] 2 [R=Me ( 1), Bu n ( 2), Ph ( 4)] were established by X-ray diffractometry. The compounds exhibit similar spiro-bicyclic structures, with the tin atom as spiro atom and chelating ligands with the oxygen atoms of the similar OPR 2 groups in trans positions. The coordination geometry around the central metal atom is octahedral, with CSnC and OSnO ( trans) angles of 180°. No significant differences were noted in the length of the tinoxygen, phosphorusoxygen and phosphorusnitrogen bonds, respectively, in relation to the different organic groups attached to tin or phosphorus atoms in a ligand moiety. The solution and solid state structures of the title compounds are discussed comparatively.

Influence of glass composition on the properties of glass polyalkenoate cements. Part II: influence of phosphate content

The influence of phosphate content of the glass on the formation of glass polyalkenoate cements was investigated. Glasses were synthesised based on (4.5−2 X)SiO 2–3.0 Al 2O 3–(3.0− X)CaO–(1.5+ X)P 2O 5–2.0 CaF 2 and X was varied from −1.5 to 0.8. The setting and working time of the cement pastes increased with the phosphate content of the glass ( X). Increasing the phosphate content resulted in an initial increase in compressive strength followed by a sharp reduction in strength. Young's modulus and un-notched fracture strength exhibited a maximum at intermediate phosphate contents. Fracture toughness reduced at high phosphate contents, whilst toughness increased. Phosphate in the glass is thought to aid glass degradation by providing additional phosphorus–oxygen bonds for hydrolysis, but may also reduce the amount of aluminium released by reducing the susceptibility of aluminium–oxygen–silicon bonds to acid hydrolysis. The released phosphate may also compete with the carboxylate groups in the polysalt matrix cement for cations inhibiting the crosslinking reaction.

Theoretical and Experimental Considerations on the Hammerhead Ribozyme Reactions: Divalent Magnesium Ion Mediated Cleavage of Phosphorus-Oxygen Bonds

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTheoretical and Experimental Considerations on the Hammerhead Ribozyme Reactions: Divalent Magnesium Ion Mediated Cleavage of Phosphorus-Oxygen BondsMasami Uebayasi, Tadafumi Uchimaru, Shinya Sawata, Takashi Shimayama, Kazunari Taira, and T. KogumaCite this: J. Org. Chem. 1994, 59, 24, 7414–7420Publication Date (Print):December 1, 1994Publication History Published online1 May 2002Published inissue 1 December 1994https://doi.org/10.1021/jo00103a038RIGHTS & PERMISSIONSArticle Views118Altmetric-Citations43LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (2 MB) Get e-Alerts Get e-Alerts

Raman scattering study of sodium di-n-pentyl phosphate aggregates and water content dependence of conformation about phosphorus-oxygen bonds in coagel phases

Raman scattering study of sodium di-n-pentyl phosphate aggregates and water content dependence of conformation about phosphorus-oxygen bonds in coagel phases

Functionalized macrocycles incorporating phosphorus-nitrogen and phosphorus-oxygen bonds. Strategies of synthesis

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFunctionalized macrocycles incorporating phosphorus-nitrogen and phosphorus-oxygen bonds. Strategies of synthesisDominique Colombo, Anne Marie Caminade, and Jean Pierre MajoralCite this: Inorg. Chem. 1991, 30, 18, 3365–3367Publication Date (Print):September 1, 1991Publication History Published online1 May 2002Published inissue 1 September 1991https://doi.org/10.1021/ic00018a001RIGHTS & PERMISSIONSArticle Views87Altmetric-Citations19LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (339 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Thermal Decomposition of Barium Amidotriphosphate

Abstract Barium amidotriphosphate (Ba3P3O9NH2·3.5H2O) was heated at 5 K min−1 in streams of dried air, humid air, and dried hydrogen chloride. cyclo-Triphosphates were not observed in any products, unlike in the pyrolysis of (NH4)4P3O9NH2·H2O. Water vapor or hydrogen chloride hydrolyzed phosphorus–nitrogen and phosphorus–oxygen bonds of the products.

THE REACTION OF ALKANEPHOSPHONIC ACID ESTERS WITH METALS

Abstract The reaction of dialkyl alkanephosphonates (methyl, ethyl, isopropyl) with alkali and earth alkali metals, respectively, has been investigated. These metals reacted with phosphonates yielding the corresponding salts of monoalkyl alkanephosphonates with the evolution of a mixture of low molecular weight gaseous products the composition of which was quantitatively determined by gas chromatographic methods. The gaseous products could be traced to the primary formation of radical fragments originating from cleavage of either the carbon-oxygen or the phosphorus-oxygen bonds. Lower alkanes were formed predominantly, but there were also traces of acetylene and also of benzene. Diisopropyl methylphosphonate showed to a large extent cleavage of the carbon-phosphorus bond, yielding a mixture of the salts of isopropylphosphonite and isopropyl methylphosphonate. Reaction mechanisms were advanced to explain some of the results.