Terrell C. Myers

31P Nuclear magnetic resonancepH titrations of myo-inositol hexaphosphate

With the use of 31P n.m.r. spectroscopy, the separate pKa values of each of the six phosphoric monoester groups of myo-inositol hexaphosphate were determined. The range of hydrogen-ion concentrations covered extended from that required for the phosphonium salts to that for the full dodecyl anion, and the determinations were carried out in the presence of sodium and tetrabutylammonium cations. The pKa for each phosphate grouping in the transition from the free acid forms of each group to the monoanion form of each group was determined to be: 1.1, C-2; 1.5, C-1 and C-3; 2.1, C-4 and C-6; and 1.7, C-5. In the mono- to di-anion transition, the pKa values were: 6.85, C-2; 7.60, C-5; 5.70 and 12.0, C-1 and C-3; and 10.0, C-4 and C-6. These data and the appearance of the 31P hexaphosphate n.m.r. multiplet are discussed in terms of conformations of myo-inositol hexaphosphate.

Biological Phosphonates: Determination by Phosphorus-31 Nuclear Magnetic Resonance

Advanced methods of phosphorus-31 nuclear magnetic resonance spectroscopy provided a method whereby biological phosphonates and phosphates can be determined on simple lipid fractions of biological origin. The spectra consist of two easily distinguished resonance bands; one corresponds to families of phosphonates, and the other corresponds to families of orthophosphates.

Phosphorus-31 nuclear magnetic resonance studies of the phosphonate and phosphate composition of the sea anemone, Bunadosoma, sp

Abstract Advanced methods of 31P nuclear magnetic resonance spectroscopy were used in the analysis of the phosphonate and orthophosphate components of fractions from the sea anemone Bunadosoma sp. and in the analysis of hydrolyzates from these fractions. The spectra consist of cleanly separated phosphonate and orthophosphate resonance bands which have been interpreted in some detail. Analysis of the data showed that certain orthophosphates are resistant to classical hydrolytic procedures. These same hydrolytic procedures bring about chemical alterations of the phosphonate subunits which can affect the phosphonate to phosphate ratio as classically determined.

Studies of biological polyphosphate through the use of phosphorus-31 nuclear magnetic resonance

Abstract Preparations from electron-dense particulate structures of Micrococcus lysodeikticus gave a single sharp signal in the middle PO 4 region of the 31 P nmr spectrum identical in chemical shift and resolution to that of added high molecular weight synthetic polyphosphate. Interaction between this material and other particle constituents was reflected by the appearance and disappearance of this signal.

Cycfization of the Phosphate Side Chain of Adenosine Triphosphate: Formation of Monoadenosine 5'-Trimetaphosphate

Monoadenosine 5-trimetaphosphate has been prepared from adeno-sine 5-triphosphate by a carbodiimide-mediated condensation. The molecule was characterized by 3lP nuclear magnetic resonance, and its 31P spectrum was simulated through the assumption of a three-phosphorus spin system. The molecule is highly reactive and is rapidly converted to adenosine triphosphate upon contact with water.

2-Aminoethylphosphonic Acid Metabolism During Embryonic Development of the Planorbid Snail Helisoma

In freshly laid egg masses of Helisoma sp., more than 95 percent of the phosphorus is found in alkylphosphonic acids, as determined by phosphorus-31 nuclear magnetic resonance spectroscopy. These compounds are metabolized during embryonic development, as shown by differential acid hydrolysis and experiments with phosphorus-33-labeled phosphoric acid. Further, nuclear magnetic resonance spectroscopy indicates phosphonic acid involvement in related snail families, including the schistosomal vector Biomphalaria glabrata.

Carbodiimide-intermediated esterification of the inorganic phosphates and the effect of tertiary amine base☆

Detailed analysis of appropriate 31P nuclear-magnetic-resonance spectra shows that under the usual laboratory conditions, carbodiimide-induced condensation of orthophosphoric acid in a number of solvents leads to condensation only slightly beyond the metaphosphate composition in the presence of strong tertiary amines; whereas in the absence of amine, the condensation proceeds into the ultraphosphate region about halfway between the metaphosphate and phosphoric anhydride compositions. With amine, the principal product consists of the cyclic trimetaphosphate anion, with one of the nonbridging oxygen atoms substituted by the urea resulting from hydration of the carboiimide, i.e., (O2-) P-O-P(O2-) -O-P(O) [N[CH(CH3)2] see article [C(O)NHCH(CH3)2]] for the condensation with diisopropylcarbodiimide. Without amine, the major product is the 1,5-mu-oxotetrametaphosphate anion see article. The well-known carbodiimide-mediated phosphorylation of alcohols with orthophosphoric acid is shown to be directly attributable to the high reactivity of the phosphate branch groups of the carbodiimide-generated ultraphosphates.

Cyclization of the phosphorus chain of the methylene-bridged analogs of adenosine triphosphate.

The phosphorus-containing side chains of two methylene-bridged analogs of adenosine triphosphate have been cyclized to produce the corresponding analogs of monoadenosine-5-trimetaphosphate. (The structures are given in the journal.) The molecules, which were generated in anhydrous media through a carbodimide-mediated condensation, were characterized by 31P nuclear-magnetic resonance, and the white-noise 1H decoupled spectra were simulated. These molecules are quite reactive and readily converted to their corresponding linear forms upon hydrolysis. The second structure contains an asymmetric phosphorus atom, and both of the possible cyclic molecules have been observed and the diasteroisomeric mixture has been isolated.