Uridine diphosphate derivative

In a recent note, Dutton and Storey170 have reported the isolation of a thermostable factor necessary to the formation of o-aminophenyl D-glucosiduronic acid in liver homogenates. The compound was said to be a uridine diphosphate derivative of D-glucuronic acid. A series of D-glucuronic acid nucleosides of uracil have recently been synthesized by Goodman171 for study. 

L2. Leloir, L. F., The enzymatic transformation of uridine diphosphate glucose into a galactose derivative. Arch. Biochem. Biophys. 33, 186-190 (1951). 

The sole component of the uridine diphosphate uronic acid fraction from animal tissues,10,124,139 Chlorella,4 red algae,83 and some bacteria118,119 is uridine 5 -(a-D-glucopyranosyluronic acid pyrophosphate) (32), whereas a similar preparation from Pneumococcus140 contains only the a-D-galactopyranosyluronic acid derivative. Both esters have been shown to occur in extracts of mung bean.141,142... 

Oligosaccharide derivatives of uridine 5 -pyrophosphate are probably present in higher plants. Cellobiose and a disaccharide composed of a glucose and an arabinose were identified among products of enzymic hydrolysis of a uridine diphosphate sugar fraction from larch wood.20... 

The uridine diphosphate ester derivatives in a non-capsulated. Type II pneumococcus and a capsulated. Type III pneumococcus were investigated by Smith, Mills, and Harper." The capsule of the Type III pneumococcus is composed of a polysaccharide having 4-0-( 8-D-glucopyranosyluronic acid)-D-glucose as a repeating unit. n-Glucuronic acid, D-glucose, and L-rhamnose are constituents of the capsular polysaccharide of the Type II pneumococcus. 

A uridine pyrophosphate derivative of Ai -acetyl-n-glucosamine which contains an extra phosphate group has been isolated from a hot-water extract of hen oviducts. Uridine 5-phosphate and uridine 5-pyrophosphate have been recovered from acid hydrolyzates of this compound. A diphosphate ester of A-acetyl-n-glucosamine can also be obtained from acid hydrolyzates of this uridine compound. Because of the catalytic activity of phospho-A -acetyl-n-glucosamine mutase toward it, it is probably AT-ace-tyl-D-glucosamine 1,6-diphosphate. 

Glucose-l-phosphate and luidine triphosphate in the presence of UDPG pyrophosphorylase form uridine diphosphate glucose (UDPG) and pyrophosphate (see Fig. 2). Glucuronic acid is derived from UDPG... 

Uridine 5 -Diphosphate. Uridine 5. (trihydrogen diphosphate) UDP uridine 5 -pyrophosphate uridine-5-pyrophosphoric acid. C9HI4N20,jPj mol wt 404.18. C 26.75%, H 3.49%, N 6.93%, O 47.50%, P 15.33%. Can be isolated from calf s fiver, thymus, and yeast. The commer -cial product is derived from yeast. Pentose nucleic acids (isolated from yeast) are digested with rattlesnake venom (freed of 5 -monoesterase) and the nucleotides are separated by chromatography Cohn, Volkin, Arch, Biochem. Biophys. 35, 465 (1952) J. Biol Chem. 203, 319 (19S3). For alternate procedures see the refs under Uridine Diphosphate Glucose. Syntheses Chambers, J. Am. Chem. Soc. 81, 3032 (1959) Moffatt, Khorana, ibid. 83, 649 (1961). 

Biosynthesis R. is derived from vomilenine, an intermediate in the biosynthetic pathway to the antiarrhyth-mic ajmaline, by glucosylation. The corresponding glucosyl transferase is membrane-bound, dependent on uridine diphosphate glucose, and has a high substrate specificity. A soluble, substrate-specific glu-cosidase effects the reversal of this reaction see also Rauvolfia alkaloids. 

Leloir, L.F. (1951) The Enzymic Transformation of Uridine Diphosphate into a Galactose Derivative , Archives of Biochemistry and Biophysics, 33, 186-90 Leloir, L.F., Staneloni, R.J., Carminatti, H. Behrens, N.H. (1973) Biosynthesis of a N,N-diacetylchitobiose Containing lipid by Liver Microsomes. Probable Dolichol Phosphate Derivative , Biochemical and Biophysical Research Communications, 52, 1285-92... 

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