Triphosphate Ions Research Articles

Hard-Shelled Glycol Chitosan Nanoparticles for Dual MRI/US Detection of Drug Delivery/Release: A Proof-of-Concept Study.

This paper describes a novel nanoformulation for dual MRI/US in vivo monitoring of drug delivery/release. The nanosystem was made of a perfluoropentane core coated with phospholipids stabilized by glycol chitosan crosslinked with triphosphate ions, and it was co-loaded with the prodrug prednisolone phosphate (PLP) and the structurally similar MRI agent Gd-DTPAMA-CHOL. Importantly, the in vitro release of PLP and Gd-DTPAMA-CHOL from the nanocarrier showed similar profiles, validating the potential impact of the MRI agent as an imaging reporter for the drug release. On the other hand, the nanobubbles were also detectable by US imaging both in vitro and in vivo. Therefore, the temporal evolution of both MRI and US contrast after the administration of the proposed nanosystem could report on the delivery and the release kinetics of the transported drug in a given lesion.

Detailed Analyses of Molecular Interactions between Favipiravir and RNA Viruses In Silico.

There are currently no antiviral agents for human metapneumovirus (HMPV), respiratory syncytial virus (RSV), mumps virus (MuV), or measles virus (MeV). Favipiravir has been developed as an anti-influenza agent, and this agent may be effective against these viruses in vitro. However, the molecular mechanisms through which the agent affects virus replication remain to be fully elucidated. Thus, to clarify the detailed molecular interactions between favipiravir and the RNA-dependent RNA polymerase (RdRp) of HMPV, RSV, MuV, MeV, and influenza virus, we performed in silico studies using authentic bioinformatics technologies. As a result, we found that the active form of favipiravir (favipiravir ribofuranosyl-5′-triphosphate [F-RTP]) can bind to the RdRp active sites of HMPV, RSV, MuV, and MeV. The aspartic acid residue of RdRp active sites was involved in the interaction. Moreover, F-RTP was incorporated into the growing viral RNA chain in the presence of nucleotide triphosphate and magnesium ions. The results suggested that favipiravir shows two distinct mechanisms in various viruses: RdRp active site inhibition and/or genome replication inhibition.

Healthy and Gestational Diabetic Human Placental Fructose 1,6 Bisphosphate Aldolase; Comparative Investigation of Kinetic Properties and Inhibition Effects of DHAP, ATP, and Mg<sup>+2</sup> ion

Fructose-1,6-bisphosphate aldolase plays an effective role in glucose metabolism and gluconeogenic pathway, and reversibly catalyzes the split of fructose 1,6-bisphosphate into the triose phosphates D-glyceraldehyde phosphate and dihydroxyacetone phosphate. Aldolase has 160 kDa molecular weight and three tissue specific isozymes. Gestational diabetes mellitus is defined as glucose intolerance that begins or is first detected during pregnancy. The placenta is a temporary established organ that operates exclusively for the time of pregnancy. It acts as a natural barrier between the maternal and fetal blood circulations and performs a wide range of endocrine and transport functions. In diabetes, the placenta undergoes a variety of structural and functional changes. Healthy and gestational diabetic human placental fructose-1, 6-bisphosphate aldolases were purified and investigated the substrate kinetic properties, in the previous studies. In this comparative study, we wanted to carry out characteristics of inhibition kinetics of aldolase in healthy and diabetic human placenta. The specific activity was defined as the number of activity units per mg of protein. Inhibition kinetics of fructose-bisphosphate aldolase was studied using dihydroxyacetone-phosphate, adenosine triphosphate, and magnesium ion as inhibitors. For healthy placental Aldolase it was detected that, adenosine triphosphate is partial competitive; dihydroxyacetone-phosphate is noncompetitive and magnesium metal is pure-competitive inhibitor. It was found that, dihydroxyacetone-phosphate is competitive; adenosine triphosphate is partial competitive and magnesium is partial competitive inhibitor of gestational diabetic human placental Aldolase.

Synthesis of a family of cyclic peptide-based anion receptors

We report here the design and synthesis of a family of novel backbone modified cyclic peptides, bearing dipicolylamine side chains for metal complexation and subsequent anion binding studies. Two approaches to the cyclic peptides were investigated. Initially, a stepwise approach was employed, involving solid-phase assembly of oxazole-based building blocks, followed by solution-phase macrolactamisation of the resulting linear precursor. The alternative strategy involved the formation of linear bisoxazole fragments in solution-phase, followed by a cyclodimerisation reaction. The zinc(II) complexes of these receptors bind selectively to di- and tri-phosphate ions over hydrogenphosphate.

ChemInform Abstract: Ambidentate Ligands, the Schizophrenics of Coordination Chemistry

Abstract Representative examples of ambidentate ligand chemistry, drawn primarily from studies published during the past decade, are presented. An overview of the physical methods used for structural elucidation is included, with major emphasis being placed on structures emanating from single crystal X-ray diffraction studies. A great variety of ambidentate ligands are covered, although the bulk of the review deals with the schizophrenic behaviour of the classic ambidentate ligands NO2−CN− NCO−, NCS− NCSe− and NCTe−. As usual, the thiocyanate ion is accorded the most extensive coverage. Other ambidentate ligands discussed include CNO−, CNS−, azaphospholes, aminobenzonitriles, 4,4'-bipyrimidine, cyanoborohydrides, CCO, ClC(CN)3, chloranilate ion, isonitroso(β-ketoimine), nicotinate ion, nitramines, nitrosobenzenes and -anilines, Ph2PC(S)NHR, phosphine/arsine, phosphine sulfide/methine, and phosphinethioamide hybrid ligands, pyridine-2-thione, N-(2-pyridyl)imidazole, 4,6-dimethylpyrimidine, saccharinate ion, H2NSO3−, SO32−, Me2SO, SO2, SO2−, SNO−, NSO−, S2O32−, S2CO2−, SeO32−, SC(O)NHR−, OSNH−, dithioimidodiphosphinate ion, dithiosquarate ion, triphosphate ion, and ureas. Transition metal complexes of ambidentate ligands are emphasized throughout the review.

Selective Anion Binding in Water with Use of a Zinc(II) Dipicolylamino Functionalized Diketopiperazine Scaffold

The design and synthesis of a diketopiperazine based anion receptor bearing two dipicolylamino arms complexed to zinc(II) ions is described. This receptor is readily prepared from the dipeptide precursor by a microwave-assisted intramolecular cyclization reaction. Upon addition of zinc(II), the receptor binds di- and triphosphate ions with high affinity and selectivity in aqueous solution, as determined by using a fluorescent indicator displacement assay.

Polyphosphate Ions Encapsulated in Oxothiomolybdate Rings: Synthesis, Structure, and Behavior in Solution.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Polyphosphate ions encapsulated in oxothiomolybdate rings: synthesis, structure, and behavior in solution.

Cyclic oxothiomolybdates containing polyphosphate ions were prepared by simple reactions in aqueous medium of the corresponding polyphosphate ions and the cyclic precursor K(2)I(2)Mo(10)S(10)O(10)(OH)(10)(OH(2))(5).15H(2)O. K(5)[Cl(P(2)O(7)]Mo(12)S(12)O(12)(OH)(12)(H(2)O)(4)].22H(2)O (1) was isolated from concentrated chloride solution (2.5 mol.L(-1)). 1 reveals a remarkable complex containing two different substrates encapsulated in a dodecanuclear ring, a H-bonded Cl(-) ion, and a covalently bonded [P(2)O(7)] group. The chloride ion in 1 can be selectively removed for a monohydrogenophosphate group yielding K(6)[(HPO(4))(P(2)O(7))Mo(12)S(12)O(12)(OH)(12)(H(2)O)(2)].19H(2)O (2), a mixed species containing a [P(2)O(7)] and a [HPO(4)] group. The substitution is accompanied by a significant change of the ring, which adopts a "pear-shape" conformation. In the presence of triphosphate ion, the "heart-shaped" decanuclear ring Rb(3)[(H(2)P(3)O(10))Mo(10)S(10)O(10)(OH)(10)].17.5H(2)O (3) is formed containing a linear [P(3)O(10)] group intimately embedded in the inorganic cyclic host. The three compounds were structurally characterized by single-crystal X-ray diffraction. The behaviors of 1, 2, and 3 in solution were studied by (31)P NMR. Variable temperature experiments, supported by a two-dimensional COSY (31)P experiment, revealed that the supramolecular interaction existing between the chloride ion and the ring in solid 1 is maintained in solution. Nevertheless, 1 remains labile, and successive equilibria were evidenced and interpreted as an ion-pair association involving a halide ion (Cl, Br, or I), responsible for the conformational change of the [P(2)O(7)] group within the cavity. The influence of the nature of the halide guest (Cl(-), Br(-), and I(-)) on the successive equilibria was studied, and the thermodynamic constant related to the postulated equilibrium was determined. The stability of the supramolecular association decreases in the order Cl > Br > I. In solution, a phosphate exchange is observed for 2 while for 3 the absence of temperature dependence of the (31)P NMR spectrum confirms the conformation of the host-guest system is blocked. Elemental analysis and infrared characterizations are also supplied.

Gas-phase hydrogen/deuterium exchange of adenine nucleotides.

Gas-phase hydrogen/deuterium exchange reactions of (de)protonated (sodiated) adenosine-5'-mono-, di- and triphosphate ions with CD(3)OD, CD(3)CO(2)D and ND(3) were achieved using a combination of electrospray ionization and Fourier transform ion cyclotron resonance mass spectrometry. The reaction kinetics are dependent on factors such as the charge state, the phosphate chain length, the properties of the exchange reactants and the sodium content. The results indicate that the overall H/D exchange may involve specific sites even if endowed with high energetic barriers. The enhanced reactivity exhibited by adenosine polyphosphate ions compared with adenosine-5'-monophosphate suggests a critical role of the polyphosphate chain in rendering conformationally accessible remote H-donor sites. Low-energy collision-induced dissociation of (sodiated) adenine nucleotides anions supports the aptitude of the (poly)phosphate chain in probing distant sites via the intermediacy of a cyclic structure.

Linkage Isomerization by Two-Dimensional 31P Nuclear Magnetic Resonance Spectroscopy. An Undergraduate Inorganic Laboratory Experiment

An application of two-dimensional 31P NMR spectroscopy is demonstrated through the characterization of linkage isomers of tetraammine(triphosphato)cobalt(III) chelates and metal-promoted hydrolysis of inorganic triphosphate ion. Unambiguous assignments of 31P resonances for two isomers, α,γ and β,γ chelates, were achieved by the direct through-bond connectivities among the three phosphate groups. The lack of such connectivity also helped to identify cobalt(III)-catalyzed hydrolysis products, orthophosphate and pyrophosphate ions. The experiment provides background information on 2-D NMR spectroscopy including the significance of pulse calibration, relaxation, evolution and mixing times, data processing, and finally, hands-on training for performing 2-D NMR experiments. The experiment is ideally suited for a senior laboratory course and may be included in the core inorganic curriculum required for a certified ACS B.S. degree.

Structural characterisation of glassy phases in the system Na 2O–Al 2O 3–P 2O 5 by MAS and solution NMR, EXAFS and vibrational spectroscopy

The structure of sodium aluminophosphate glasses with a fixed O/P ratio of 4 and 3.5 has been investigated. For the monophosphate compositions, the phosphate network is completely depolymerised so that the glassy network is built through the aluminium atoms which are distributed on three different sites but lying mainly in tetrahedral coordination. 31P Magic angle spinning (MAS)-NMR spectra show the existence of three different cationic environments for the PO 4 3− ions. In the glasses with the diphosphate compositions, we observed the disproportionation of some diphosphate groups into monophosphate and triphosphate ions crosslinked by the aluminium atoms whose average coordination increases. The diphosphate groups give a typical vibrational spectrum but the detection of the other phosphate molecular groups is not obvious. The Ga–Al substitution allows better vibrational assignment. MAS-NMR spectra of these two cations show that these two conditional glass former does not behave exactly in the same way in the glassy state.

Relationship between Material Surroundings and Analytical Chemistry in Our Lives. Adsorption of various phosphorus oxoacid ions on titanium oxide treated with alginate.

The adsorption of various phosphorus oxoanions on titanium oxide treated with alginate was investigated by capillary-type isotachophoresis. The various phosphorus oxoacid anions such as orthophosphate (P1), phosphite (P3), hypophosphite (P1), diphosphate (P2) and triphosphate (P3) ions were separated at pH 4.0 with a 0.01 M histidine hydrochloride-0.075% triton X-100 mixture as the leading electrolyte and 0.01 M hexanoic acid as the terminating electrolyte. The PU (potential unit) value increased in the order P3<P2<P1<P3<P1. The calibration curves for P1, P3 and P1, P2 and P3 were linear in the range of 10120, 1080 and 1050 μmol, respectively. The relative standard deviation for the measured phosphorus oxoacid anions were less than 5% (n=5). The maximum amounts adsorbed on the titanium oxide treated with alginate (μmolg-1)of P1, P3, P1, P2 and P3 by stirring (500 rpm)for 5 h (the amount of P1 reached the maximum after 1.5 h and subsequently decreased little by little) at pH 1.6 were 320, 270, 180, 140 and 90, respectively.

Thermodynamics of protonation of AMP, ADP, and ATP from 50 to 125�C

The interaction of adenosine 5′-monophosphate (AMP), adenosine 5′-diphosphate (ADP), and adenosine 5′-triphosphate (ATP) ions with protons in aqueous solution has been studied calorimetrically from 50 to 125°C and 1.52 MPa. At each temperature, the reaction of acidic AMP with tetramethylammonium hydroxide was combined with the heat of ionization for water to obtain the enthalpy of protonation of AMP, while the reactions of HCl with deprotonated tetramethylammonium salts of ADP and ATP were used to obtain the enthalpies of protonation of ADP and ATP. Equilibrium constant K, enthalpy change ΔHo, entropy change ΔSo, and heat capacity change ΔCpo values were calculated for the stepwise protonation reactions as a function of temperature. The reactions involving the first protonation of AMP, ADP, and ATP and the third protonation of ADP and ATP were endothermic over the temperature range studied, while that involving the second protonation is exothermic for AMP and ADP, but is exothermic below 100°C and endothermic at 125°C in the case of ATP. Consequently, log K values for the first and third protonation reactions (phosphate groups) increase while those for the second protonation reaction (N1-adenine) decrease in the cases of AMP and ADP and go through a minimum in the case of ATP as temperature increases. The ΔHo values for all protonation reactions increase with temperature. The magnitude and the trend for the ΔHo, ΔSo, and ΔCpo values with temperature are discussed in terms of solvent-solute interactions. The magnitude of the ΔCpo values for the second protonation is consistent with little interaction between the phosphate ion and the protonated N1 site of the adenine moiety in AMP, but indicates moderate interaction between these groups in ADP, and strong interaction in ATP.

Raman intensities and polarizability parameters (EOPs) of some oxo-anions of group V, VI and VII elements in aqueous solution: general trends

Polarizability data from Raman intensity and refractive index measurements are compared within the two isoelectronic series of compounds: PO 4 3−, SO 4 2−, ClO 4 − and SO 3 2−, ClO 3 −. Sets of electrooptical parameters (EOPs) are given and tentative correlations with d-orbital population on the central ion and electronegativity are computed. Trace properties of the Raman tensors show clearer trends than does the total scattering activity. Trace scattering intensities of Orthophosphate, Diphosphate and Triphosphate ions are proportional to the number of PO 4 units.

Determination of sulfate, orthophosphate, and triphosphate ions by flow injection analysis with the lead ion selective electrode as detector

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDetermination of sulfate, orthophosphate, and triphosphate ions by flow injection analysis with the lead ion selective electrode as detectorJ. F. Coetzee and C. W. GardnerCite this: Anal. Chem. 1986, 58, 3, 608–611Publication Date (Print):March 1, 1986Publication History Published online1 May 2002Published inissue 1 March 1986https://doi.org/10.1021/ac00294a027RIGHTS & PERMISSIONSArticle Views111Altmetric-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 (544 KB) Get e-Alerts Get e-Alerts

Mechanism of cobalt(III)-promoted hydrolysis of triphosphate ion

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMechanism of cobalt(III)-promoted hydrolysis of triphosphate ionPaul R. Norman and Richard D. CorneliusCite this: J. Am. Chem. Soc. 1982, 104, 9, 2356–2361Publication Date (Print):May 1, 1982Publication History Published online1 May 2002Published inissue 1 May 1982https://doi.org/10.1021/ja00373a004RIGHTS & PERMISSIONSArticle Views146Altmetric-Citations34LEARN 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 (783 KB) Get e-Alerts Get e-Alerts

The effect of cobalt(III) complexes on the rate of hydrolysis of triphosphate ion

The effect of cobalt(III) complexes on the rate of hydrolysis of triphosphate ion

Gel chromatographic investigation of the competitive binding of magnesium and copper(II) ions with polyphosphate ions

An atomic-adsorption flow detector combined with a gel chromatogaphic column (Sephadex G-25) was applied in the investigation of the competitive binding of magnesium and copper(II) ions with diphosphate and triphosphate ions. Some preliminary results are given and the practical utility of the theoretical equations presented in evaluating the competitive binding of magnesium and copper(II) ions is discussed.

Builder Effects of Sodium Tripolyphosphate on Oily Soil Removal

The effects upon surface tension for the aqueous solution of sodium dodecyl sulfate (SDS) by concentration of calcium and triphosphate ions were investigated. The results were interpreted by change of surface adsorption for dodecyl sulfate salt under concentration of sodium tripolyphosphate (STP). Interfacial tension between the solution mentioned above and two sorts of oil, i. e. oleic acid and liquid paraffin, and the contact angle of the two liquid interface on polyester films were measured. Residual works of detergency for these systems were calculated from these values and the effects of STP concentration upon the STP-hard water systems were discussed. It was concluded that the detergent builder effects of STP were dependent on types of oil. For oleic acid soil, soap formation in situ as an alkaline salt emulsified the oil itself. On the other hand, for paraffin droplet soil, they assisted to increase the contact angle on the film and to remove easily from the film by rolling-up mechanism.

Heats and Entropies of Reaction of Alkaline-earth Metal Ions with Pyrophosphate and Triphosphate Ions

The thermodynamic stability constants of the complexes of pyrophosphate and triphosphate ions with Mg (II), Ca (II) and Sr (IL) are evaluated by the pH titration method. The enthalpy changes associated with the formation of the 1 : 1 complexes at 25°C are determined by a direct calorimetric method or calculated from the variation of the thermodynamic stability constants with temperature. From these values of the themodynamic stability constants and enthalpies, the corresponding entropy changes are calculated. The results are as follows (Table 2); (a) in all cases the complex formation is endotherm and entropically favored, (b) the ΔS0 decreases with increasing radius of the metal cations, while the ΔH0 does not, (c) theΔS0 of a triphos- phate complex is always larger than that of the corresponding pyrophosphate complex. All these results are explained in terms of present theories of metal chelate formation in aqueous solution.