Ribitol phosphate, hydrolysis

The isomerism existing between the pairs of nucleotides was attributed to the different locations of the phosphoryl residues in the carbohydrate part of the parent nucleoside,49 63 since, for instance, the isomeric adenylic acids are both hydrolyzed by acids to adenine, and by alkalis or kidney phosphatase to adenosine. Neither is identical with adenosine 5-phosphate since they are not deaminated by adenylic-acid deaminase,68 60 and are both more labile to acids than is muscle adenylic acid. An alternative explanation of the isomerism was put forward by Doherty.61 He was able, by a process of transglycosidation, to convert adenylic acids a" and 6 to benzyl D-riboside phosphates which were then hydrogenated to optically inactive ribitol phosphates. He concluded from this that both isomers are 3-phosphates and that the isomerism is due to different configurations at the anomeric position. This evidence is, however, open to the same criticism detailed above in connection with the work of Levene and coworkers. Further work has amply justified the original conclusion regarding the nature of the isomerism, since it has been found that, in all four cases, a and 6 isomers give rise to the same nucleoside on enzymic hydrolysis.62 62 63 It was therefore evident that the isomeric nucleotides are 2- and 3-phosphates, since they are demonstrably different from the known 5-phosphates. The decision as to which of the pair is the 2- and which the 3-phosphate proved to be a difficult one. The problem is complicated by the fact that the a and b" nucleotides are readily interconvertible.64,64... 

The production of ribitol diphosphates on acid hydrolysis, and also on alkaline hydrolysis, of the product obtained after oxidation of the teichoic acid with periodate establishes the presence of ribitol phosphate residues joined to each other through phosphodiester groups. On oxidation of the polymer (o-alanine removed) with periodate, many of the ribitol residues were oxidized, and the quantitative data obtained support a structure in which there are 7-8 units in the chain. 

Poly(ribitol phosphate) synthetase has been found in particulate fractions from Staphylococcus aureus H, and Lactobacillus plantatrum.lt ll-m The bulk of the activity in Lactobacillus plantarum was in crude, cell-wall preparations, and the enzyme is apparently located in the membrane, although intimate association with the wall itself has been suggested. Unlike the natural teichoic acid, the enzymically synthesized ribitol phosphate polymer was readily extracted with phenol hydrolysis by acid and by alkali gave the expected products, and oxidation with periodate indicated a chain length of 5-9 units, a value which compares well with that of 8 units for the natural polymer in the walls of this organism. 

Acid hydrolysis of cytidine ribitol pyrophosphate led to a series of products, depending on the conditions of hydrolysis. L-Ribitol 1-phosphate (n-ribitol 5-phosphate), isomeric ribitol phosphates formed by acid-catalyzed migration of the phosphate group from the terminal position, and 1,4-anhydro-DL-ribitol were isolated. 

Oxidation of (8) yielded a ribonic acid phosphate (9), whose properties differed from those of the ribonic acid 5-phosphate obtained by similar hydrolysis and oxidation of inosine 5 -phosphate. Moreover, reduction of (8) allegedly gave a ribitol phosphate (10) which was optically inactive. From these studies, it followed that the phosphoric moiety in (10) is esterified by the 3-hydroxyl group of the ribitol moiety. Similarly, a yeast adenylic acid, obtained from an alkaline hydrolysate of yeast ribonucleic acid, was deaminated to an inosinic acid that was different... 

Carbohydrate SXA, on acidic hydrolysis, yields galactose, galactose phosphate, galactosamine, ribitol, anhydroribitol, ribitol phosphates, and inorganic phosphate. Alkaline hydrolysis of carbohydrate SXA, followed by enzymic dephosphorylation and separation of the product... 

Ribitol phosphate has been identified as a component of the lipopolysaccharide from Proteus mirabilis D52. Acidic hydrolysis of the lipopolysaccharides from several strains of P. mirabilis from serogroups 016 and 033 liberated 1,4-anhydro-ribitol, which was identified by g.l.c.-m.s. of the peracetylated derivative. Ribitol has a role in the serological specificities exhibited by these lipopolysaccharides. 

During the hydrolysis of ribitol phosphate at pH i to 2 the migration of phosphate is slow in relation to the formation of anhydro 1,4-ribitol. The latter reaction mechanism is interpreted by Baddiley as a protonization of the ester oxygen atom at position i with subsequent reaction with the OH at position 4 (Fig. ii) (cf. ref. 77). 

Baddiley and coworkers42 have studied the structure of S13, which is composed of D-galactose, D-glucose, 2-acetamido-2-deoxy-D-glucose, and ribitol residues, and phosphate groups in the molar proportions 2 1 1 1 1. O-Acetyl groups are also present. A neutral pentasaccharide was obtained by hydrolysis with alkali, followed by enzymic dephosphorylation. On mild, acid hydrolysis, this yielded two main products, a trisaccharide (19) and a disaccharide (20), the structures of which were determined by conventional methods. 

In 1932 Levene and Harris128 showed that the hydrolysis of xanthylic acid gave rise to the formation of a D-ribose phosphate which was not identical with the known D-ribose 5-phosphate. Since xanthylic acid is the monophosphate derivative of a ribofuranoside of xanthine it followed that the new phosphate was either D-ribose 2-phosphate or the 3-isomer (L). Shortly thereafter the same authors129 succeeded in reducing the new D-ribose phosphate with hydrogen in the presence of platinum oxide to a ribitol phosphoric acid (LI) which was completely... 

Alkaline hydrolysis of the teichoic acid gave a mixture of monophosphates of 0-D-glucosyl-D-ribitol (XVII), only traces of diphosphates, and no phos-pho diesters. Removal of D-glucose by 8-D-glucosidase gave ribitol 1-phosphate and ribitol 2-phosphate (and no ribitol 3-phosphate). Thus, the phospho diester linkages are at positions 1 and 5 in the polymer. 

An interesting counterpart of the above reaction has been found by Baddiley and associates in the hydrolysis of L-ribitol 1-phosphate (which is the same as n-ribitol 5-phosphate) which, under acid conditions N hydrochloric acid), results in the formation of 1,4-anhydro-DL-ribitol. 

The racemization apparently takes place before hydrolysis. Similar results have been obtained with D-xylitol 5-phosphate and n-mannitol 6-phosphate. 1,4-Anhydro-ribitol is also formed from the treatment of ribitol with dilute mineral acid. However, since the anhydro compounds are produced more readily from the phosphates than from the unsubstituted alditols, it has been suggested that the latter compounds are not formed as intermediate products. The mechanism of this reaction has been explained by assuming protonation of the ester oxygen atom, with subsequent intra-... 

Acidic hydrolysis of SXXXIV ([ ]d -1-30.8° nitrogen, 1.41% phosphorus, 3.59% acetyl, 11.4%) yielded galactose, glucose, ribitol and its phosphates, anhydroribitol, and inorganic phosphate. " The dis-... 

N-oc-t-Boc-L-His Oleyl imidazole L-glutamic add dioleylester ribitol (stabilizer) DVB toluene Co(II)Cl2+water Using substrate analog surface imprinting by W/0 emulsion polymerization hydrolysis of N-a-Boc-L-Ala p-nitrophenyl ester in isooctane/phosphate buffer [1751... 

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