Sodium uridine-5 -phosphate

Sodium uridine-5 -phosphate 224 is converted by HMDS 2/TCS 14 and pyrroh-dine at 145 °C, via the assumed persilylated intermediate 225, and after transsilyla-tion with boiling methanol and addition of NaOH, crystalline sodium-cytidine-5 -phosphate 226 in 69% yield [49] (Scheme 4.19). 

On silylation-amination of the disodium salts of inosine-5 -phosphate 238a or of guanosine-5 -phosphate 238 b with benzylamine, the phosphate moieties are also transiently protected during amination by silylation (cf also the silylation of uridine-5 -phosphate 224) to give, after transsilylation with methanol and addition of NaOH, the desired sodium salt of N -benzyladenosine-5 -phosphate 239a in 80% yield and the sodium salt of the 2-amino derivative 239 b in 78% yield [64] (Scheme 4.23). 

Although the 2, 3 -cyclic phosphates of adenosine, cytidine, guano-sine, and uridine appear to be stable in aqueous solution between, approximately, pH 4 and 9, they are hydrolyzed under more-strenuous conditions (for example, 0.1M hydrochloric acid for 1 hour at room temperature or 0.5 M sodium hydroxide for 12 hours at 37°) to give a mixture of 2 - and 3 -phosphates287 in approximately equal amounts. An appreciation of this aspect of the chemistry of cyclic phosphates was of considerable importance in elucidating the mechanism of the chemical degradation of ribonucleic acid.288... 

Uridine 3 -phosphate (147) was prepared by Hall and Thedford by the phosphorylation of 2, 5 -di-0-trityluridine with 2-cyanoethyl phosphate and iVjiV -dicyclohexylcarbodiiinide to give the diester (146). This diester was de-esterified with alkali, and then hydrolyzed with 80% acetic acid at 100° for 90 minutes, to give (147). The structure of (14S) had been rigorously established by Yung and Fox, who methanesulfonated (145) to obtain (148). Treatment of (148) with sodium benzoate in N,N-di-methylformamide gave the 2,3 -anhydronucleoside (149). The anhydro... 

Fig. 11.1.4. Separation of uracil and 5-fluorouracil bases, nucleosides and nucleotides by reversed phase ion-pair HPLC. Chromatographic conditions column, Bondapak Cig (300 x 4 mm) mobile phase, (from 0-30 min) 0.1 mM tetrabutylammonium hydrogen sulphate (Cjg), 2.5 mM tetraethylammonium bromide (Cg) and 2% methanol in 2 mM sodium acetate, 1.5 mM phosphate buffer, pH 6.0 (Buffer A) (from 30-50 min) Buffer A-i-30 mM phosphate detection, UV at 254 nm. Peaks FU, fluorouracil FUR, fluorouracU riboside/ FUdR, fluorouracil deoxyriboside FUMP, fluorouridine 5 -monophosphate 5 dFUR, 5 -deoxyfluorouracil riboside FdUMP, deoxyfluorouri-dine monophosphate UDPG, uridine diphosphoglucose UDP, uridine diphosphate dUDP, deoxyuridine monophosphate UTP, uridine triphosphate. Reproduced from Au et al. (1982), with permission.

Prepare individual standards (Sigma) of adenosine-5 -phosphoric acid, cytidine 5 -phosphate (sodium salt), guanosine-5 -phosphate (sodium salt), and uridine-5 -phosphate (disodium salt) as l-pg/p. solutions in deionized water. Prepare each standard by dissolving 10 mg of the nucleotide in 10 ml of water. Prepare a mixed standard of the four nucleotides at 1 Ag/)il for each. To obtain the mixed standard, weigh 10 mg of each nucleotide and dissolve in 10 ml of water to achieve a concentration of 1 )ig/ J.l for each. 

The following separations (approximate values included) will be achieved for both individual nucleotides and the mixed standard guanosine-5 -phosphate (sodium salt), 0.34 adenosine-5 -phosphoric acid, 0.48 cytidine-5 -phosphate (sodium salt), 0.60 and uridine-5-phosphate (disodium salt), 0.74. The compounds will appear as dark spots against a bright fluorescent background at 254 nm. 

Source phase sodium phosphate buffer (100 mM, pH 7.4), sodium dithionite (10 mM) Organic phase carrier 6 (1 mM) in chloroform Receiving phase sodium phosphate buffer (100 mM, pH 7.4), sodium dithionite (10 niM). 15 %. transport rate in the presence of carrier 6 divided by the rate in the absence of carrier. The source phase initially contained 41 mM catecholamine. TTie starting concentration of transported species was adjusted to give a similar rate of back ound diffusion. Source initially contained 1.36 mM glycoside. Source initially contained 20 mM uridine. 

Nudeosides, Nudeotides, and their Derivatives.—Uridine, uridine 5 -(niethyl oxyacetate), 6-chloro-9-j8-D-ribofuranosylpurine, 6-methyl-9-j8-D-ribofurano-sylpurine, 5-acetyl-l-(3,5-0-isopropylidene-j8-D-xylofuranosyl)uracil, 2 -de-oxycytidine, the 1 1-complex of cytidine and iV-benzyloxycarbonylglutamic acid, l-(3-0-methyl-j8-D-arabinofuranosyl)cytosine, 2 -deoxyadenosine 5 -(sodium phosphate), 9-j8-D-arabinofuranosyladenine hydrochloride, 8-j8-D-ribofuranosyladenine, 8 - (2 - deoxy - oc - d - erythro - pentofuranosyl) - 6 -hydroxy-purine, l-methyl-4-jS-D-erythrofuranosyl-4-imida2oline-2-thione, and 4,6-di-0-acetyl-l,3 -anhydro-2,3-dideoxy-3-[3-hydroxy-5-methyl-(2if)-l,2,6-thiadiazin-2-yl l,l-dioxide]-a-D-n 6o-hexopyranose (455). ... 

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