Adenosine arabinoside

The introduction of an azido substituent on the C-2 position of cytosine arabinoside (ara-C) (149) or adenosine arabinoside (ara-A) (154) has been found to confer favourable properties to these antimetabolites. Ara-C, one of the most effective drugs for the treatment of human acute myeloblastic leukaemia [176], is subject to rapid metabolic deamination, by deoxycytid-ine deaminase, to the inactive uridine derivative ara-U (152) Scheme 3.5), and the drug has a half-life of approximately 12 minutes in man [177]. Efforts to circumvent this problem by modifying the 2 -arah/ o-position led... 

Langston-Pavan, D. ed. (1975) Adenosine Arabinoside An Antiviral Agent, Raven Press, New York. 

Deoxycoformycin inhibits Adenosine Deaminase [8] to increase the levels of dATP which inhibits Ribonucleotide Reductase. Infusing Adenosine Arabinoside together with Deoxycoformycin increases inhibition of the Reductase further via... 

Resistance to purine and pyrimidine antimetabolites, such as adenosine arabinoside and cytosine arabinoside. by neoplastic cells that produce deaminases has stimulated a search... 

Another example of molecular modification is the synthetic nucleoside adenosine arabinoside (1-23). This compound has a pronounced antiviral activity against herpes virus and is therefore widely used in modern chemotherapy. 

ADCC ADP AM ara-C ATP BAPTA antibody-dependent cellular cytotoxicity adenosine diphosphate acetoxymethyl ester cytosine arabinoside adenosine triphosphate bis- (o-aminophenoxy)-ethane-N,N,N, N -tetraacetic acid... 

Vidarabine (adenine arabinoside, ara-A) is phos-phorylated in the cell to the triphosphate derivative which blocks DNA synthesis by inhibiting DNA polymerase. It is indicated for infections with herpes simplex virus and varicella-zoster however its use has to a large extend been surpassed by aciclovir. It is administered topically or intravenously. It is inactivated rapidly by adenosine deaminase which for systemic use necessitates constant infusion of the drug. Vidarabine is the least toxic of the purine analogues. Nausea and vomiting are the most frequent adverse effects and neurotoxicity may occur. 

Vidarabine [vye DARE a been] arabinofuranosyl adenine, ara-A, adenine arabinoside) is one of the most effective of the nucleoside analogs and is also the least toxic. However, it has been supplanted clinically by acyclovir, which is more efficacious and safe. Although vidarabine is active against herpes simplex virus type 1 (HSV-1), HSV-2, and varicella-zoster virus (VZV), its use is limited to treatment of immunocompromised patients with herpes simplex keratitis or encephalitis, or VZV infections. Vidarabine, an adenosine analog, is converted in the cell to its 5 -triphosphate analog (ara-ATP), which is postulated to inhibit viral DNA synthesis. Some resistant herpes virus... 

Vidarabine (adenine arabinoside), an analogue of adenosine, does not interfere with purine biosynthesis but affects DNA synthesis. 

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