Polyphosphate complexes

Sequestration forms the basis for detergent and water-treatment appHcations of polyphosphates. Sequestration of hardness ions by sodium tripolyphosphate used in detergent formulations prevents the precipitation of surfactants by the hardness ions. Sodium polyphosphate glass (SHMP) may be added to water system to prevent the formation of calcium or magnesium scales by reducing the activity of the hardness ions. However, if the ratio of cation to polyphosphate is too high at a given pH, insoluble precipitates such as may result instead of the soluble polyphosphate complexes. The... 

F. Martin, P. Rubini, R. Cote, and 1. Kottke, Aluminium polyphosphate complexes in the mycorrhizal basidiomycete Laccaria bicolor a A1 NMR study. Planta 194 241 (1994). 

Condensed (poly) phosphates may exert different effects on calcium utilization than the aforementioned effects of simple (ortho-) phosphates. Polyphosphates have a much greater affinity for calcium than do orthophosphates, and soluble calcium-polyphosphate complexes are readily formed in the gastric and intestinal environments. In addition, polyphosphates must be hydrolyzed by an intestinal alkaline phosphatase (27) prior to absorption. We have found polyphosphates to be incompletely (80.5%) hydrolyzed to orthophosphate during the digestive process in young adult males when calcium intake was low only 56% of a 1 g phosphorus supplement was absorbed from a polyphosphate sources as compared to 71% from an orthophosphate source (5). 

Biaglow JE, Kachur AV (1997) The generation of hydroxyl radicals in the reaction of molecular oxygen with polyphosphate complexes of ferrous ion. Radiat Res 148 181-187 Biaglow JE, Field KD, Manevich Y, Tuttle S, Kachur A, Uckun F (1996) Role of guanosine triphosphate in ferric ion-linked Fenton chemistry. Radiat Res 145 554-562 Bielski BHJ (1991) Studies of hypervalent iron. Free Radical Res Commun 12/13 469-477 Bielski BHJ, Allen AO, Schwarz HA (1981) Mechanism of disproportionation of ascorbate radicals. J Am Chem Soc 103 3516-3518... 

J. Chaloupka and A. Babicky (1958). The ribonucleic acid-polyphosphate complex and its separation. 

R. N. Reusch (1989). Poly-beta-hydroxybutirate/calcium polyphosphate complexes in eukaryotic membranes. Roc. Soc. Exper. Biol. Med.., 191, 377-381. 

R. D. Cornelius, P. A. Hart and W. W. Cleland (Inorg. Chem., 1977, 16, 2799) discuss isomerism in cobalt(III)-polyphosphate complexes. 

The artificial model of a cell membrane was prepared using biomimetic PHB and the calcium polyphosphate complex (poly-P) incorporated into lipid bilayers of 1,2-dierucoylphosphatidylcholine. It was found that PHB/poly-P channels show high conductance for Ca and Na cations . 

Reusch RN (1989) Poly-beta-hydroxybutyrate calcium polyphosphate complexes in eukaryotic membranes. Proc Soc Exp Biol Med 191 377-381 Reusch RN (1992) Biological complexes of poly-P-hydroxybutyrate. FEMS Microbiol 103 119-129... 

Reusch, R.N., Huang, R., and Bramble, L.L. (1995) Poly-3-hydroxybutyrate/ polyphosphate complexes form voltage-activated Ca2-1 channels in the plasma membranes of Escherichia coli. Biophys. /., 69, 754-766. 

A poly(3-HB)/calcium polyphosphate complex has been isolated from E. coli and other species. This complex, whose structure is thought to consist of two high molecular weight concentric helices, is believed to form ion channels (Chapter 11.1) in natural membranes. 

Only a few of the p emitters Usted in O Table 46.4 have been investigated for therapeutic applications. Many of these radionuclides are reactor produced, limiting the types of carrier molecules for which they are suitable. Several radiocolloids labeled with Au have been studied for intracavitary therapies however, their relatively high degree of leakage from the treatment site has limited their clinical utility (Virkkunen et al. 1967 Spencer 1978 Harbert 1987). Treatment ofbone pain with polyphosphate complexes of both and has been... 

The ability of the polyphosphates to form water-soluble complexes with calcium has been known for a long time. The phenomenon of binding alkaline earth ions in soluble complexes, and thus preventing the formation of undesirable precipitates, is generally called sequestration. This was the subject of earlier patent literature. The role of these calcium-polyphosphate complexes in softening of water was described in Chapter 23 of the book edited by Bailar. The complexing of a number of metal ions with the various phosphates was reviewed in detail in 1958. ... 

As usual there have been a number of papers on the hydrolysis of polyphosphates. Complexes of [VO] + or [VO] + with polyphosphates give species in which phosphate hydrolysis is much more rapid than for the uncomplexed species. We may also note the appearance of further evidence that the oxidation reactions of peroxodiphosphate involve hydrolysis in the rate-determining stage. Studies on the oxidation of antimony(iii), hydrazine, nitrite, and hypophosphite have appeared. ... 

Essentially the same procedure is reported for encapsulation by gelatin-polyphosphate complex coacervation at pH 4-5 Compared with gum arabic, however, maximum coacervation is achieved at only 1 part of commercially available sodium hexametaphosphates to 10-20 parts of acid-extracted pigskin gelatin. This is due to the lower apparent (ionic) equivalent weight of polyphosphates." The gelatin-... 

Metallic ions, such as iron and copper afifect polyphosphate. If an iron-polyphosphate complex is formed, dissolution rather than inhibition would proceed. If copper ions are present, a galvanic couple would be formed by the passage of copper ions from the polyphosphate film to the iron substrate, and corrosion would progress. 

---