Manganese diphosphate

Owing to its stability, manganese diphosphate is very convenient as a calibrant for magnetic susceptibility measurements. Its magnetic susceptibility follows the Curie-Weiss law between -80 and +485°. 

After it is cooled, the solidified mixture is washed with distilled water to remove excess manganese salt and the alkaline salt formed. After filtration, the manganese diphosphate is dried by heating in air at 200°. 

The manganese diphosphate produced by this method is a pale-pink powder composed of crystallites between 0.2 and 0.8 m in diameter. It is stable in air and slightly soluble in water. 

The compound crystallizes in the monoclinic system with unit-cell dimensions of a = 6.64 A b = 8.58 A c = 4.54 A (3 = 102.8°. These data agree well with those reported by Lukaszewicz.4 Manganese diphosphate can be identified according the following powder diffraction lines ... 

The magnetic susceptibility, measured with a vibrating sample magnetometer (Foner), calibrated with nickel (purity 99.99% — specific susceptibility at 293°K 55 cgs/g) at 293 0.2°K with a magnetic field of 17,700 G, is 101.39 0.20 10"6 cgs/g. This value may be compared with 101.65 0.20 10 6 cgs/g for manganese diphosphate prepared by thermal decomposition of the ammonium manganese phosphate. The value calculated from Reference 7 is 101.96 0.20 cgs/g. 

Hydrogen peroxide is produced during the autoxidation of some 2,5-dihydropyrazines and 1,2,3,6-tetrahydropyrazines, e.g., compound 195. Hydrogen peroxide production is strongly catalyzed by manganese diphosphate complexes.387 388... 

Prussic acid, see Hydrogen cyanide Pyrite, see Iron disulfide Pyrochroite, see Manganese(H) hydroxide Pyrohytpophosphite, see diphosphate(IV)... 

Pyrolusite, see Manganese(IV) oxide Pyrophanite, see Manganese titanate(IV)(2—) Pyrophosphate, see Diphosphate(V)... 

In report discuss the methodical aspects determination of magnesium, manganese, cobalt, zinc to their joint presence in nitric, sulphuric, chloric salts, and peculiarity of the analysis using to solid solutions of the hydrated diphosphates. 

Concentration limits of the diphosphate-ion, admissible to determination of magnesium and cobalt, manganese and cobalt, zinc and cobalt by spectrophotometric method with application of the l-(2-pyridylazo)-resorcinol (PAR) are presented. Exceeding maintenance of the diphosphate-ion higher admissible supposes a preliminary its separation on the anionite in the H+-form. The optimum conditions of cobalt determination and amount of the PAR, necessary for its full fastening are established on foundation of dependence of optical density of the cobalt complex with PAR from concentration Co + and pH (buffer solutions citrate-ammoniac and acetate-ammoniac). 

This enzyme [EC 2.5.1.17], also referred to as cob(I)-alamin adenosyltransferase or aquacob(I)alamin adeno-syltransferase, catalyzes the reaction of cob(I)alamin with ATP and water to produce adenosylcobalamin, orthophosphate, and pyrophosphate (or, diphosphate). A cofactor for this enzyme is manganese ion. 

Mangafodipir. Manganese(II) dipyridoxyl diphosphate (MnDPDP), or mangafodipir trisodium, is classified as a drug or therapeutic agent, and no production data were found for it. 

In some kinases, such as nucleoside diphosphate kinase, " an intermediate step is the phosphoryl transfer to a group belonging to the enzyme, as happens in ATPase and as was discussed in detail for alkaline phosphatase (Section V.B). In other kinases the phosphoryl transfer occurs directly from the donor to the acceptor in a ternary complex of the enzyme with the two substrates.Often metal ions like magnesium or manganese are needed. These ions interact with the terminal oxygen of the ATP molecule, thus facilitating the nucleophilic attack by the acceptor. The metal ion is often associated with the enzyme. For mechanistic schemes, see the proposed mechanism of action of alkaline phosphatase, especially when a phosphoryl enzyme intermediate is involved. 

C Spectroscopy has also been used to study the interaction of Mn(II) and bicarbonate with D-ribulose 1,5-diphosphate carboxylase (Miziorko and Mildvan, 1974). The binding of manganese by ribulose... 

A somewhat similar picture has been obtained by electron-spin resonance studies of two manganese-containing enzymes creatine kinase and muscle enolase. In the former, manganese was shown to form a bond to the coenzyme (adenosine diphosphate) and to the substrate, but not to the protein in the latter, manganese seemed to act as a bridge between substrate and protein (Cohn and Leigh, 1962). 

Transfer to protein. The first dolichol diphosphate oligosaccharide which was found to act as donor of oligosaccharide to protein was the glucose labelled compound (Parodi et al., 1972). The enzyme as well as the acceptor protein was found in the microsomal fraction of liver. The reaction requires manganese ions. 

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