Antimetabolites antiviral agents

Cytamen cyanocobalamin. cytarabine [ban, inn. jan, usan] (cytarabine hydrochloride [usan] Ara C Cytosar Cytosar-U ) is an antimetabolite cytotoxic ANTICANCER and ANTIVIRAL AGENT isolated from the mushroom Xerocomm nigromaculatus. It works by interfering with pyrimidine synthesis. Clinically, it can be used sys-temically in anticancer treatment mainly of acute leukaemia, cytidine diphosphate choline dticoline. cytidine diphosphocholine dticoline. cytisine is an alkaloid with CNS STIMULANT, RESPIRATORY STIMULANT and psychoactive properties. It has been used clinically as a respiratory stimulant in Russia. It is a common cause of poisoning by the seeds of Cytisus laburnum. 

Mycil chlorphenesin tolnafitate. mycophenolate mofetil [usan] (CellCept ) is converted in vivo to n cophenolic add, which has antimetabolite cytotoxic properties. It shows experimental activity as an ANTICANCER and ANTIVIRAL AGENT. It may be clinically useful in treating psoriasis and as an ANTU.EISHMANIAL. It shows IMMUNOSUPPRESSANT properties, and is used in the prophylaxis of acute kidney rejection, mycophenolic acid [ban, inn, usan] is usually... 

In the area of classical antimetabolites, a host of highly active new nucleosides have been found that show promise in the chemotherapy of cancer and viral diseases. Classical antimetabolites appear to have a virtual monopoly in the field of antiviral agents. After the discovery of the first effective drugs against,the Herpes virus 28b, c 25), a new breakthrough may have been... 

C10H11 f3n2o5 Antiviral agent Antimetabolite Ophthalmic drops 70-00-8 April 1980/ Monarch Pharms Alcon... 

A substance inhibiting cell growth by competing with, or substituting for, a natural substrate in an enzymatic process. Sulfonamides and trimethoprim are antimetabolites, as are many antiviral agents and drugs used in cancer chemotherapy. 

Fludarabine is a purine antimetabolite. Fludarabine is a fluorinated nucleotide analog of the antiviral agent vidara-bine. Fludarabine s metabolite appears to act by inhibiting DNA polymerase alpha, ribonucleotide reductase, and DNA primase, thus inhibiting DNA synthesis. It is indicated in refactory or progressive chronic B-ceU lymphocytic leukemia. 

Fludarabine phosphate, a fluorinated deamination-resistant nucleotide analog of the antiviral agent vidarabine (9-P-D-arabinofuranosyl-adenine), is active in CLL and low-grade lymphomas. After rapid extracellular dephosphorylation to the nucleoside fludarabine, it is rephosphorylated intracellularly by deoxycytidine kinase to the active triphosphate derivative. This antimetabolite inhibits DNA polymerase, DNA primase DNA ligase, and ribonucleotide reductase, and is incorporated into DNA and RNA. The triphosphate nucleotide is an effective chain terminator when incorporated into DNA, and the incorporation of fludarabine into RNA inhibits RNA function, RNA processing, and mRNA translation. 

Sulfonamides and trimethoprim are antimetabolites, as are many antiviral agents and drugs used in cancer chemotherapy. 

Topical Antiviral Drugs Several antiviral agents with marked systemic toxicity (bone marrow, hepatic, renal) are used mainly as topical drugs for herpes simplex eye infections, including keratitis. These dmgs include three antimetabolites idoxuridine, cytarabine, and trifluo-rothymidine. 

Most antiviral agents are nucleotide antimetabolites similar in structure to the nucleotide antimetabolites used in cancer chemotherapy. The viruses that lend themselves to drug therapy are those with complicated genomes. The herpes simplex virus has over 120 genes making it likely that there are unique enzymes, such as the viral thymidine kinase, required for... 

Contents E.J.Ariens, A.-M.Simonis Design of Bioactive Compounds. -T.J.Bardos Antimetabolites Molecular Approaches for Designing Antiviral and Antitumor Compounds. -T.A.Connors Alkylating Agents. -E.De Clercq Synthetic Interferon Inducers. - C.Woenckhaus Synthesis and Properties of Some New NAD Analogues. 

A very intense search for antiviral and cancerostatic agents has led to the synthesis of countless nucleoside analogues. Virtually all possible chemical modifications (on the bases, sugars, and even the phosphate) have been made and tested in vitro and in vivo. Two of the most intensively studied antimetabolites are arabinosyl cytosine (araCyd) and formycin A (see Fig. 3-1). The former is used in the clinical treatment of oncogenic viruses and leukemia. After transformation to the triphosphate it is incorporated into DNA, where it may be a chain terminator. Formycin A and B (A is the Ado analogue, B the Ino analogue) are both in the syn conformation and have strong antiviral activity. 

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