Alditol phosphates

There are solitary examples of other alditol phosphates as components of this class of polymers. Arabinitol 1-phosphate is part of the S. pneumoniae type 17F capsular polysaccharide. o-Glucitol 6-phosphate is a component of the group-specific polysaccharide from group B Streptococcus, which has a most unusual, ramified structure. In a polysaccharide from Nocardia... 

The alditol phosphate analogue of D-arabinose-5-phos-phate was a 3-fold less potent inhibitor than D-erythronic acid-... 

The characteristic components of the cytoplasmic membrane of Gram-positive bacteria are the amphiphilic macromolecules lipoglycan and lipoteichoic acid [39,40] (O Fig. 8). Lipotei-choic acids possess in their saccharide chain alditol phosphates as characteristic components, whereas lipoglycans are linear or branched polysaccharides linked to diacylglycerol. These molecules may be further substituted by phosphoglycerol residues. Since lipoteichoic acids and lipoglycans are not found in the same bacterium they are believed to replace each other... 

Again, in principle, alditols might be oxidized to the corresponding ketoses by NAD - or NADPe-linked dehydrogenases, or to the aldoses by NADP -linked dehydrogenases. Alternatively, the aldoses might be phosphorylated. Aldoses and ketoses may be phosphorylated, and alditol phosphates oxidized to aldose or ketose phosphates. These compounds are likely to be catabolized by the reactions of the Embden-Meyerhof glycolytic pathway or of the pentose cycle. 

Inhibition of the homologous SVI rabbit anti-Pn VI system showed that large amounts (30-100 mmoles) of most sugars give up to 15% inhibition, and sugar phosphates and alditol phosphates inhibit to as much as 25%, with little relation to their presence in or absence from SVI. Kabat showed that related oligosaccharides are usually better inhibitors than monosaccharides. Thus, the phosphate-free tetrasaccharide repeating unit of SVI is a more efficient inhibitor than ribitol, ribitol 1-phosphate, or any... 

A similar mechanism can be invoked to explain the construction of some of the phosphorylated polysaccharides, where the transfer of alditol phosphate is replaced by a transfer of sugar phosphate. 

In general, these polymers are very difficult to solubilise and they are clearly components of very orderly complexes within membranes. It should be noted that where there is a simple transfer of a glycerol phosphate or ribitol phosphate group from phospholipid to a growing polymer, the net process is very like that involved in transporting alditol phosphate across a membrane by way of phospholipid in other words, the simplest possible cycle is a shuttle. 

Cell wall polysaccharide contains alditol phosphate... 

Teichoic acids (16) are bacterial polymers in which alditols, glycerol, or ribitol are joined through the primary hydroxyl groups via phosphate diester linkages. 

The term polysaccharide has also been widely used for macromolecules containing glycose or alditol residues in which both glycosidic and phosphate diester linkages are present. 

The alcoholysis of the cyclic phosphate of catechol by alditols can lead, after acid hydrolysis of intermediate, cyclic phosphates, to the selective formation of phosphoric esters of the primary hydroxyl groups in the alditols. Thus, erythritol and D-mannitol afford, after chromatographic purification of the reaction products, their 1-phosphates in yields of 31 and 38%, respectively.217 The method was used to convert riboflavine into riboflavine 5 -phosphate.218 1-Deoxy-1-fluoro-L-glycerol has been converted into the 3-(dibenzyl phosphate) in 54% yield by selective reaction with dibenzyl phosphorochloridate. 219... 

Adenine, 9-(a-D-ribofuranosyl)-, 115 Adenosine, 115 5-phosphate, 204 5-pyrophosphate, 204 5-triphosphoric acid, 204, 231 —, 2-deoxy-, 228, 229 5-triphosphste, 231 —, iV -hydroxy-, 5-phosphate, 232 Adenylyl peptides, 204 Aerobacter aerogenes, 314, 315 Agrobacterium tumefaciens, 327 Alanine, (3,4-dihydroxyphenyl)-, 269 —, phenyl-, 236, 237, 264, 265, 268 Alditols, acid dissociation constants of, 32,... 

Alditols are often observed as the end-products of monosaccharide metabolism that are stored in various cellular and tissue compartments with low redox potentials. However, there are also examples of alditols as important metabolic intermediates allowing the interconversion of rare forms of certain monosaccharides. In enteric bacteria such as Escherichia coli the hexitol galactitol is taken up through enzyme II of the phosphoenol pyruvate-dependent phosphotransferase system and accumulated inside the cell as galactitol 1-phosphate. The genes involved in galactitol metabolism have been cloned on a 7.8 kb DNA fragment [201]. 

The formation of alditols in eye lenses is one of the major complications in diabetic patients. Interestingly, the detailed molecular pattern of the lens alditols allows us to differentiate between the diabetic lens having increased concentrations of sorbitol 3-phosphate and fructose 3-phosphate, and the galactosemic lens, where the major products are galactitol 2-phosphate and galactitol 3-phosphate [202]. 2,5-Anhydro-D-mannitol is an analogue of fructose that has become popular in cellular metabolic studies using perfused rat liver [203]. 

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-... 

A study has been conducted on the effects that sugar alditols and aminoalditols have on the rate of phosphate ester hydrolysis in the substrates bis(4-nitro-phenyOphosphate and supercoiled DNA, when catalysed by lanthanide cations. See Chapter 23 for the effect of solvents on the relative stabilities of the complexes formed between alditols and lanthanide cations. 

Deoxy-sugar phosphates have been synthesized by catalytic hydrogenation of various enol phosphates. Thus the alditol derivatives (15) and (l6) were obtained from 1,2- and 2,3-unsaturated pre-Me O -0-P(0Me)2... 

Amino acid analysis of a strong acid hydrolysate (2 N HCl at 100° C for 3 h) identified only glutamic acid and this was confirmed by gas chromatography-mass spectroscopy (Fig. 4). Mild acid hydrolysis (0.5 N HCl at 80°C for 1 h) followed by direct insertion mass spectroscopy gave a spectrum identical to authentic ribose-5-phosphate (Fig. 5). Borate electrophoresis of the alditol derived from the stored material and of its acid... 

---