Phosphorylation agents

It is estimated that mote than 25 x 10 different potentially toxic OP esters can be made using Schrader s classic (27) formula for effective phosphorylating agents, (39), where R and are short-chain alkyl, alkoxy, alkylthio, or alkylamino groups, and X is a displaceable moiety with a high energy P-bond such as E or acyl anhydride, and the pentavalent phosphoms atom is bonded to oxygen or sulfur. 

In addition to the nucleic acids themselves, nucleic acid derivatives such as ATP are involved as phosphorylating agents in many biochemical pathways, and several important coenzymes, including NAD+, PAD, anti coenzvme A, have nucleic acid components. 

In order to obtain anionic polyoxyethylene phosphate surfactants, either the terminal hydroxy group of a polyoxyethylated hydrophobic substance is reacted with a phosphorylating agent or a phosphate ester is oxalkylated. Most often aliphatic and aliphatic-aromatic alcohols are first treated with an alkylene oxide and afterward with one of the phosphorylating agents, such as P4OI0, POCl3, phosphoric acid, or polyphosphoric acid [39-48]. 

It is also possible to use salts of polyphosphoric acids, e.g., trimetaphosphate, as the phosphorylating agent in reaction with alkylamines, as is shown in Eq. (75). 

Compound (1) phosphorylates phosphate monoesters and alcohols, although with the latter a considerable excess of alcohol is necessary to obtain satisfactory yields. In the absence of mercuric ions the milder phosphorylating species (3) can be isolated which converts monoalkyl phosphates to pyrophosphate diesters in good yield but does not react appreciably with alcohols unless catalytic amounts of boron trifluoride are added. Amine salts of (3) are converted to phosphoramidates on heating. In the presence of silver ions, O-esters of thiophosphoric acid behave as phosphorylating agents and a very mild and convenient procedure suitable for preparing labile unsymmetrical pyrophosphate diesters, such as the... 

In a study of the attack of the ambident nucleophile ethanolamine on a series of phosphorylating agents (48) and related compounds it was observed that the proportion of O-phosphorylation increased as R and R varied in the series McaN, RO, R and as X varied in the series R2PO, CN, F, this last giving exclusive 0-phosphorylation. These results were... 

Silver ions will oxidatively desulphurize nucleoside and other phos-phorothioates to generate a phosphorylating agent. This reaction has been utilized for the preparation of nucleotide coenzymes and has the advantage that it can be carried out on a large scale without the formation of contaminating symmetrical pyrophosphates. 

This shows that the combination of diphenylphosphate and arylsulfonyl-3-nitro-triazole is a powerful phosphorylating agent in pyridine solution. 

All attempts to phosphorylate GAP with triphosphate were unsuccessful, so that AmTP is an important phosphorylating agent. 

In recent studies, Glindemann et al. (1999, 2000) attempted to obtain definite answers to one of the basic problems of prebiotic phosphorus chemistry were there realistic enrichment mechanisms for the phosphorus derivatives required in prebiotic syntheses Only if the phosphorylating agents were present in concentrated form could successful reactions have taken place. 

As early as 45 years ago, G. Schramm et al. (1962) carried out the synthesis of AMP, ADP and ATP using ethyl metaphosphate as the phosphorylating agent. These successful syntheses led to the formation of longer nucleotide chains however, they by no means correspond to the conditions present on the primordial Earth. Thus, the question as to the source of the phosphates remains paramount. According to Schwartz (1998), the following phosphate sources deserve consideration ... 

The phosphoramidic chloride (11) has been employed to phosphorylate phenols and alcohols, including carbohydrates.16 Other activity in phosphorylation chemistry has been mostly concentrated in two main areas. In the first of these, Japanese workers have continued their studies on the use of 2-substituted-4-nitrophenyl-phosphoric acids. The 7V-protonated form of the 2-dimethylamino-compound (12 R = Me) is a better phosphorylating agent than the corresponding 2-diethylamino-compound. The reaction of (12) with hydroxy-amines results in selective O-phos-... 

Nolan and co-workers have extended the scope of transesterification reactions to include phosphonate esters as phosphorylating agents [137]. In this publication the authors use dimethyl methylphosphonate 273 and benzyl alcohol with a variety of imidazolylidene carbenes (Table 23). The nse of molecnlar sieves to absorb methanol leads to increased conversion however, longer reaction times lead to decreased... 

In fact, the ester can be utilized to synthesize ATP from ADP that is, it is a phosphorylating agent, and a more powerful one than ATP ... 

There are features in this conversion that closely resemble the dark reactions of photosynthesis, which build a C6 chain (fructose) from Cs chains (Section 20-9). For example, the reactants are either phosphate esters or mixed anhydrides, and the phosphorylating agent is ATP ... 

The mixed anhydride of phosphoric acid and glyceric acid then is used to convert ADP to ATP and form 3-phosphoglycerate. Thereafter the sequence differs from that in photosynthesis. The next few steps accomplish the formation of pyruvate by transfer of the phosphoryi group from C3 to C2 followed by dehydration to phosphoenolpyruvate. Phosphoenolpyruvate is an effective phosphorylating agent that converts ADP to ATP and forms pyruvate ... 

Enzymes immobilized on PAN gel, unless stated otherwise. The actual phosphorylating agent, ATP, is regenerated either by acetyl phosphate and acetoldnase, or enolpyruvate phosphate and pyruvate kinase. Phosphorylations by a mixture of the common ribonucleotide triphosphates. Not isolated.4 Soluble enzymes. Enzymes immobilized on agarose.1 Enzymes enclosed in a dialysis bag. 

When methyl 4,6-benzylidene-2-desoxy-a-D-galactoside (LXXXVI)126 was treated with phosphorus oxychloride in pyridine at —40°, followed by barium hydroxide,236 it gave amorphous barium methyl 4,6-benzyli-dene-2-desoxy-a-D-galactoside 3-phosphate (LXXXVII). If diphenyl-phosphoryl chloride [diphenylchlorophosphonate, (PhO)2POCl]236 240 in pyridine was used as the phosphorylating agent, then crystalline (methyl... 

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