Nucleosides compounds

Interest in preparing C-nucleoside compounds has prompted syntheses involving C-alkylation. Thus, 12 reacts with (i A)-2,3-0-isopropylideneglyceraldehyde to give only 13 (Equation 5) <1996MI549>. 

A number of currently prescribed NRTIs are shown in Figure A.44. Compounds A.155 through A.158 are all analogues of pyrimidine nucleosides. Compounds A.159 and A.160 are both purine nucleoside analogues. Abacavir (Ziagen, A.160) is inactive until it is metabolized to carbovir (A.161) in vivo. The seven drugs in Figure A.44 were approved in the United States over a span of more than 25 years. Zidovudine reached the market first in 1987, and emtricitabine was the last to be approved in 2003. The steady release... 

More recently, Schueler and Kreuger [100] compared these two latter desorption methods, PDMS (or FFID) and LDMS (or LID), in a study of nucleoside compounds and their corresponding bases (Fig. 13). 

Estrada, E., Vilar, S., Uriarte, E. and Gutierrez, Y. (2002) In silico studies toward the discovery of new anti-HIV nucleoside compounds with the use of TOPS-MODE and 2D/3D connectivity indices. 1. 

Sugars, nucleosides and their analogs are the classes of compounds most often involved in enzyme catalyzed phosphorylation. Typical carbohydrate phosphorylations are included in Table 13-4, together with the phosphorylation of other non-nucleosidic compounds. Table 13-5 gives an overview of the enzyme catalyzed phosphorylation reactions of nucleosides and their analogs. A few representative examples of nucleoside sugars are listed, for more detailed information consult the review, refs[74> 80, 81]. 

A review with 57 references has appeared on regio- and stereo-selective syntheses of C-glycosides by palladium-mediated glycal— aglycon coupling. A new application, shown in Scheme 2, offers very selective routes to 2-deo -C-nucleoside compounds. 

Application of the Ivanov reaction led to the production of compound (7) and chain extension methods applied to 5 -aldehydes have been used to produce modified uronic acid nucleosidic compounds (Chapter 20). 

Compounds 1-9, as well as other 3 -azido analogues of pyrimidine deoxyribo-nucleosides (compounds 25-37), which were also synthesized in our laboratory, were evaluated against HIV-1 in vitro, and the antiviral activity was expressed by the concentration ( jM) that inhibits 50% of viral replication. The results are shown in Table 2. ... 

The CuAAc methodology was used to prepare a variety of nucleoside bioconjugates bearing spin labels or fluorescent probes (compounds 27-30) [40 -43] and was also used for the F-labeling of nucleosides (compound 27G) (Figure 10.5) [44]. 

SUGINO, Y., SuGiNO, N., Okazaki, R., and Okazaki, T. (1960). Studies on deoxy-nucleosidic compounds. Biochim. Biophys. Acta 40, 417—434. 

ANTIBIOTICS - NUCLEOSIDES AND NUCLEOTIDES] (Vol 3) -titanium dioxide in [TITANIUM COMPOUNDS - INORGANIC] (Vol24)... 

Antibiotic A201A. Antibiotic A201A (23), produced by S. capreolus is an /V -dimethyladenine nucleoside stmcturaHy similar to puromycin (19). Compound (23) which contains an aromatic acid and monosaccharide residues (1,4), inhibits the incorporation of amino acids into proteins but has no effect on RNA or DNA synthesis. Compound (23) does not accept polypeptides as does (19), and does appear to block formation of the initiation complex of the SOS subunit. It may block formation of a puromycin-reactive ribosome. 

I eplanocins. Neplanocins A—D and E (37—41) are carbocycHc nucleoside antibiotic products oi Ampullariella regularis (1,4) that are stmcturaHy related to (36) in that they contain either a cyclopentene or epoxy cyclopentane ring (121,122). The chemical syntheses of (37—41) and the 3-deazaneplanocins have been reported (123—126). Compound (37), which is converted to its 5 -triphosphate, has potent antitumor and antiviral activities (127—129). It strongly inhibits SAM in ceUs and vimses (128—131) and is converted to the 3 -keto derivative by A-adenosyUiomocysteine hydrolase (132,133). 

DiaZepin Nucleosides. Four naturally occurring dia2epin nucleosides, coformycin (58), 2 -deoxycoformycin (59), adechlorin or 2 -chloro-2 -deoxycoformycin (60), and adecypenol (61), have been isolated (1—4,174,175). The biosynthesis of (59) and (60) have been reported to proceed from adenosine and C-1 of D-ribose (30,176,177). They are strong inhibitors of adenosine deaminase and AMP deaminase (178). Compound (58) protects adenosine and formycin (12) from deamination by adenosine deaminase. Advanced hairy cell leukemia has shown rapid response to (59) with or without a-or P-interferon treatment (179—187). In addition, (59) affects interleukin-2 production, receptor expression on human T-ceUs, DNA repair synthesis, immunosuppression, natural killer cell activity, and cytokine production (188—194). 

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