Uridine sodium

Ci9H23N7012p- Na+-6 H20 Adenylyl-(3, 5 )-uridine sodium salt, hexahydrate ADYPUR10 37 427... 

Bismuth sodium triglycollamate 3 J5 -BisO-(p-nitrobenzoyl)-2 -deoxy-S-(trifluoromethyl) uridine a/Xfll-J rif luorothymidine Bis(phenyleneoxy) cyclohexane Clinofibrate... 

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). 

The reactions of the sodium salt of diethyl malonate and 4-(triisopropyl-phenylsulfonyloxide) derivatives of tris-(fe/7-butyldimethylsilyl)uridine (487, R = H) and di-(rm-butyldimethylsilyl)thymidine (487, R = Me) in THF at 0°C afforded the corresponding diethyl 4-pyrimidinylidenemalo-nates (488) in 88-89% yields (87TL2821). 

Wee, T. G., Frey, P. A. Studies on the mechanism of action of uridine diphosphate galactose 4-epimerase. Substate dependent reduction by sodium borohydride. J. Biol. Chem. 248, 33—40 (1973). 

Experimental conditions have been found for oxidation of uridine 5 -(a-D-galactopyranosyl pyrophosphate) with D-galactose oxidase.265 The reaction product is the a-D-ga(acto-hexodialdose derivative (55). Analogous treatment of uridine 5 -(acetamido-2-deoxy-a-D-galactopy-ranosyl pyrophosphate), and subsequent reduction of the product with sodium borohydride-t, affords a convenient synthesis of the 6 -tritiated derivative.2656... 

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... 

The 5,6-double bond in uracil, 5-fluorouracil, /V-alkyluracils, thiouracils, and uridines adds sodium sulfite or bisulfite to give the corresponding 5,6-dihydro-6-sulfonic acid salts. Bisulfite addition to cytosines and cytidine may be succeeded by a second reaction involving nucleophilic replacement of the amino group, for example, by water. 

Reactions of nucleophiles. A number of nucleophilic reagents add reversibly at the 6 position of pyrimidines. Thus, bisulfite adds to uridine (Eq. 5-10).528 Hydroxylamine (HONH2) adds in a similar fashion to give a compound with -HNOH in the 6 positions.528 Sodium borohydride (NaBH4), which can be viewed as a donor of a hydride ion (H ), reduces uridine to the 5,6-dihydro derivative. This presumably occurs by attack of the hydride ion at position 6 in a manner analogous to the reaction of bisulfite in Eq. 5-10. 

C19H23N7Na0i2P-6H20 Adenylyl-(3 — 5 )-uridine (ApU), sodium salt, hexahydrate104... 

Of incidental interest is the observation that an w-chlorine atom may be replaced by iodine under Oldham and Rutherford s conditions, without affecting secondary sulfonyloxy groups. Thus, Levene and Tipson107 found that 5-chloro-5-deoxy-2,3-di-0-tosyl-uridine affords the corresponding 5-deoxy-5-iodo derivative plus sodium chloride on the other hand, methyl 4-chloro-4-deoxy-2,3,6-tri-0-tosyl-a-D- glucoside gives117 the 4-chloro-4,6-dideoxy-6-iodo derivative. These observations, taken... 

Mixtures of photolabile 2 - and 3 -0-(2-nitrobenzyl)ribonucleosides were obtained in good yields when adenosine, uridine, cytidine, and inosine were treated with 2-nitrophenyldiazomethane in the presence of tin(II)chloride [362]. The dibutylstan-nylene approach has been used for the preparation of 2 -(4-nitrobenzyl)uridine [366]. 2-Nitrobenzyl chloride and sodium hydride in DMF gave the 2 -ethers in 26-37% yield, depending on the starting nucleoside [363, 367]. 

CH3), which was converted with aqueous alkali to 5 -methyl-2 -thiouri-dine.233 Similarly, 3-ethoxyacryloyl isothiocyanate (LXXI, R = H, R" = C2H5) plus LXX yielded the tribenzoate ester of LXXIII (R = H) which was converted with sodium alkoxide or ammonia to 2 -thiouridine. These D-ribo-2 -thionucleosides exhibit ultraviolet spectral properties similar to those shown by l-methyl-2-thiouracil123 and an enzymically prepared sample of 2 -thiouridine.236 Treatment of 2 -thiouridine with monochloroacetic acid afforded uridine this finding permitted assignment of the l-(/ -D-ribo-furanosyl) structure to these 2-thiouracil nucleosides.233... 

Purine and pyrimidine bases and their nucleosides (adenosine, adenine, cytidine, cytosine, guanosine, guanine, inosine, thymine, uridine, uracil) ODSS (octadecyl sulfonated silica), 10 pm Acetonitrile . 8 mM sodium acetate, pH 4.5 (40 60) 270 mm x 20.5 pm i.d 205 mm effective lengtl... 

Absorption of purines and pyrimidines by cestodes occurs by a combination of passive diffusion and mediated transport. In H. diminuta, purine and pyrimidine uptake is very complex and seems to involve at least three carrier systems (Table 6.9), two of which appear to bind several substrate molecules simultaneously (631). Pyrimidine transport was thought to involve allosteric regulation because the relation between initial uptake and substrate concentration was sigmoidal. However, more recent work (890) has indicated that the sigmoidal kinetics of pyrimidine transport in H. diminuta is an isotope effect, obtained only when 2-14C-labelled pyrimidines were used absorption kinetics of methyl-l4C- and 3H-labelled pyrimidines were hyperbolic. Nucleosides (thymidine, uridine, adenosine and guanosine) are absorbed by H. diminuta, H. citelli and H. microstoma via a specific sodium-dependent, mediated system involving at least two carriers (347). Interestingly, the mechanism displays a diurnal periodicity in H. diminuta (616, 617). 

Seeman NC, Rosenberg JM, Suddath FL, Kim JJP, Rich A (1976) RNA double-helical fragment at atomic resolution. I. The crystal and molecular structure of sodium adenylyl-3, 5 -uridine. J Mol Biol 104 109-144... 

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