Pyrophosphorylation

FIGURE 11.16 Phosphoryl and pyrophosphoryl group transfer, the major biochemical reactions of nncleoddes. 

Preparation of 6-azacytidine-5 -phosphate by direct phosphorylation with cyanoethylphosphate was not successful. The substance could be prepared, however, on ammonia treatment of 4-thio-6-azauridine-5 -phosphate which was obtained by phosphorylation of 2, 3 -isopropyl-iden-4 thio-6-azauridine with pyrophosphoryl chloride. From mor-pholidate of 6-azacytidine-5 -phosphate, 6-azacytidine-5 -diphosphate was prepared by the action of phosphoric acid. ... 

There are some means for synthesis of defined primary or secondary esters. Monoester salts of phosphoric acid, for instance, are prepared by addition of alcohol or ethoxylated alcohol, alkali fluoride, and pyrophosphoryl chloride (C12P0)20 in a molar ratio of 0.9-1.5 0.05-1 1.0 at -50 to +10°C and hydrolysis of the Cl-containing intermediates with base. Thus, 32.3 g (C12P0)20 was treated at -50°C with 23.9 g lauryl alcohol in the presence of 0.7 g KF and the mixture was slowly warmed to room temperature and hydrolyzed with H20 and 40% NaOH to give 83% sodium monolauryl phosphate. The monoester salts showed comparable or better washing and foaming efficiency than a commercial product [12]. 

Phosphorylation of cholesterol followed by the normal hydrolytic work-up gives the phosphate monoester, not the symmetrical pyrophosphate diester as previously claimed. Cholesteryl phosphorodichloridate and some related steroidal phosphorodichloridates have been prepared from the action of pyrophosphoryl chloride on the appropriate alcohol ... 

General preparative procedures for the preparation of A -alkyl phos-phoramidic dichlorides (10) and A TV -dialkyl phosphorodiamidic chlorides (11) from the appropriate amine and phosphoryl chloride have been described. With weakly basic amines, pyrophosphoryl chloride was... 

The binding of NAD+ or NADH to lactate18 or D-glyceraldehyde 3-phosphate19 dehydrogenases involves the pyrophosphoryl group. Data recently obtained from 31P n.m.r. of these enzymes show that the environments of the pyrophosphoryl group... 

Phosphoribosylpyrophosphate (PRPP) synthetase is one of the very few enzymes which transfer a pyrophosphoryl group from ATP in one step. When the synthesis is carried out in lsO-enriched water, lsO is incorporated into the PRPP, but not into AMP.91 The lsO in the PRPP arises from a pre-exchange between the H2180 and the ribose phosphate, and hence the results confirm that fission of the /5-P—O bond takes place. PRPP and ATP are starting materials in the biosynthesis of histidine, and Ai-(5 -phospho-D-ribosyl)adenosine triphosphate (29) is an intermediate. The... 

A vitamin whose pyrophosphorylated form is an essential coenzyme in so-called a condensation and a cleavage reactions, whose cardinal feature is that the scissile bond always lies immediately adjacent to the carbonyl group. 

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