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Arabinosyl Nucleosides
Arabinosyl nucleosides are derivatives of the nucleosides. They contain – in contrast to most nucleosides – instead of the β-D-Ribofuranose the β-D-Arabinofuranose. They are mostly used as cytostatics or virostatics. Examples File:Cytarabin.svg, Cytarabine File:Vidarabine.svg, Vidarabine File:Nelarabine structure.svg, Nelarabine File:Fludarabine.svg, Fludarabine File:Clofarabine.svg, Clofarabine File:Sorivudine.svg, Sorivudine Sorivudine (INN), is a nucleoside analogue antiviral drug, marketed under trade names such as Usevir ( Nippon Shoji, Eisai) and Brovavir (BMS). It is used for the treatment of varicella zoster virus infections. Pharmacology Feature * First-line ... File:Clevudine Formulae.png, Clevudine Literature * W. E. Müller: "Rational design of arabinosyl nucleosides as antitumor and antiviral agents", Jpn J Antibiot. 1977 Dec;30 Suppl:104–120; . * {{Organic-chem-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleosides
Nucleosides are glycosylamines that can be thought of as nucleotides without a phosphate group. A nucleoside consists simply of a nucleobase (also termed a nitrogenous base) and a five-carbon sugar (ribose or 2'-deoxyribose) whereas a nucleotide is composed of a nucleobase, a five-carbon sugar, and one or more phosphate groups. In a nucleoside, the anomeric carbon is linked through a glycosidic bond to the N9 of a purine or the N1 of a pyrimidine. Nucleotides are the molecular building-blocks of DNA and RNA. List of nucleosides and corresponding nucleobases The reason for 2 symbols, shorter and longer, is that the shorter ones are better for contexts where explicit disambiguation is superfluous (because context disambiguates) and the longer ones are for contexts where explicit disambiguation is judged to be needed or wise. For example, when discussing long nucleobase sequences in genomes, the CATG symbol system is much preferable to the Cyt-Ade-Thy-Gua symbol system (see '' N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ribose
Ribose is a simple sugar and carbohydrate with molecular formula C5H10O5 and the linear-form composition H−(C=O)−(CHOH)4−H. The naturally-occurring form, , is a component of the ribonucleotides from which RNA is built, and so this compound is necessary for coding, decoding, regulation and expression of genes. It has a structural analog, deoxyribose, which is a similarly essential component of DNA. is an unnatural sugar that was first prepared by Emil Fischer and Oscar Piloty in 1891. It was not until 1909 that Phoebus Levene and Walter Jacobs recognised that was a natural product, the enantiomer of Fischer and Piloty's product, and an essential component of nucleic acids. Fischer chose the name "ribose" as it is a partial rearrangement of the name of another sugar, arabinose, of which ribose is an epimer at the 2' carbon; both names also relate to gum arabic, from which arabinose was first isolated and from which they prepared . Like most sugars, ribose exists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arabinose
Arabinose is an aldopentose – a monosaccharide containing five carbon atoms, and including an aldehyde (CHO) functional group. For biosynthetic reasons, most saccharides are almost always more abundant in nature as the "D"-form, or structurally analogous to D-glyceraldehyde.The D/L nomenclature does not refer to the molecule's optical rotation properties but to its structural analogy to glyceraldehyde. However, L-arabinose is in fact more common than D-arabinose in nature and is found in nature as a component of biopolymers such as hemicellulose and pectin. The L-arabinose operon, also known as the araBAD operon, has been the subject of much biomolecular research. The operon directs the catabolism of arabinose in ''E. coli'', and it is dynamically activated in the presence of arabinose and the absence of glucose. A classic method for the organic synthesis of arabinose from glucose is the Wohl degradation. : Etymology Arabinose gets its name from gum arabic, from which i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytostatics
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemotherapy may be given with a curative intent (which almost always involves combinations of drugs) or it may aim to prolong life or to reduce symptoms (palliative chemotherapy). Chemotherapy is one of the major categories of the medical discipline specifically devoted to pharmacotherapy for cancer, which is called ''medical oncology''. The term ''chemotherapy'' has come to connote non-specific usage of intracellular poisons to inhibit mitosis (cell division) or induce DNA damage, which is why inhibition of DNA repair can augment chemotherapy. The connotation of the word chemotherapy excludes more selective agents that block extracellular signals (signal transduction). The development of therapies with specific molecular or genetic targets, whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virostatics
Antiviral drugs are a class of medication used for treating viral infections. Most antivirals target specific viruses, while a broad-spectrum antiviral is effective against a wide range of viruses. Unlike most antibiotics, antiviral drugs do not destroy their target pathogen; instead they inhibit its development. Antiviral drugs are one class of antimicrobials, a larger group which also includes antibiotic (also termed antibacterial), antifungal and antiparasitic drugs, or antiviral drugs based on monoclonal antibodies. Most antivirals are considered relatively harmless to the host, and therefore can be used to treat infections. They should be distinguished from viricides, which are not medication but deactivate or destroy virus particles, either inside or outside the body. Natural viricides are produced by some plants such as eucalyptus and Australian tea trees. Medical uses Most of the antiviral drugs now available are designed to help deal with HIV, herpes viruses, the he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytarabine
Cytarabine, also known as cytosine arabinoside (ara-C), is a chemotherapy medication used to treat acute myeloid leukemia (AML), acute lymphocytic leukemia (ALL), chronic myelogenous leukemia (CML), and non-Hodgkin's lymphoma. It is given by injection into a vein, under the skin, or into the cerebrospinal fluid. There is a liposomal formulation for which there is tentative evidence of better outcomes in lymphoma involving the meninges. Common side effects include bone marrow suppression, vomiting, diarrhea, liver problems, rash, ulcer formation in the mouth, and bleeding. Other serious side effects include loss of consciousness, lung disease, and allergic reactions. Use during pregnancy may harm the baby. Cytarabine is in the antimetabolite and nucleoside analog families of medication. It works by blocking the function of DNA polymerase. Cytarabine was patented in 1960 and approved for medical use in 1969. It is on the World Health Organization's List of Essential Medicines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vidarabine
Vidarabine or 9-β-D-arabinofuranosyladenine (ara-A) is an antiviral drug which is active against herpes simplex and varicella zoster viruses. Discovery In the 1950s two nucleosides were isolated from the Caribbean sea sponge, sponge ''Tethya crypta'': spongothymidine and spongouridine; which contained D-arabinose rather than D-ribose. These compounds led to the synthesis of a new generation, sugar modified nucleoside analog vidarabine, and the related compound cytarabine. In 2004 these were the only marine related compounds in clinical use. The drug was first synthesized in 1960 in the Bernard Randall Baker lab at the SRI International, Stanford Research Institute (now SRI International). The drug was originally intended as an anti-cancer drug. The anti-viral activity of vidarabine was first described by M. Privat de Garilhe and J. De Rudder in 1964. It was the first nucleoside analog antiviral drug, antiviral to be given systemically and was the first agent to be licensed f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nelarabine
Nelarabine, sold under the brand names Arranon (US) and Atriance (EU), is a chemotherapy medication used for the treatment of T-cell acute lymphoblastic leukemia (T-ALL) and T-cell lymphoblastic lymphoma (T-LBL). Nelarabine is a prodrug of arabinosylguanine nucleotide triphosphate (araGTP), a type of purine nucleoside analog, which causes inhibition of DNA synthesis and cytotoxicity. Pre-clinical studies suggest that T-cells are particularly sensitive to nelarabine. In October 2005, it was approved by the FDA for acute lymphoblastic leukemia and T-cell lymphoblastic lymphoma that has not responded to or has relapsed following treatment with at least two chemotherapy regimens. It was later approved in the European Union The European Union (EU) is a supranational political and economic union of member states that are located primarily in Europe. The union has a total area of and an estimated total population of about 447million. The EU has often been des ... in Octobe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fludarabine
Fludarabine is a purine analogue and antineoplastic agent. It is generally used as its 5-O-phosphorylated form known as fludarabine phosphate, sold under the brand name Fludara among others. It is a chemotherapy medication used in the treatment of leukemia and lymphoma. These include chronic lymphocytic leukemia, non-Hodgkin's lymphoma, acute myeloid leukemia, and acute lymphocytic leukemia. It is given by injection into a vein or by mouth. Common side effects include nausea, diarrhea, fever, rash, shortness of breath, numbness, vision changes, and feeling tired. Severe side effects include brain dysfunction, low blood cell counts, and lung inflammation. Use in pregnancy will likely result in harm to the fetus. Fludarabine is in the purine analog family of medications and works by interfering with the duplication of DNA. Fludarabine was approved for medical use in the United States in 1991. It is on the World Health Organization's List of Essential Medicines. Medical us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clofarabine
Clofarabine is a purine nucleoside antimetabolite marketed in the United States and Canada as Clolar. In Europe and Australia/New Zealand the product is marketed under the name Evoltra. It is FDA-approved for treating relapsed or refractory acute lymphoblastic leukaemia (ALL) in children after at least two other types of treatment have failed. Some investigations of effectiveness in cases of acute myeloid leukaemia (AML) and juvenile myelomonocytic leukaemia (JMML) have been carried out. Ongoing trials are assessing its efficacy for managing other cancers. Approval Clolar was Food and Drug Administration (FDA) approved 28 December 2004. (Under accelerated approval regulations requiring further clinical studies.) Side effects * Tumor lysis syndrome (TLS). Clofarabine quickly kills leukaemia cells in the blood. The body may react to this. Signs include hyperkalemia, hyperuricemia, and hyperphosphatemia. TLS is very serious and can lead to death if it is not treated right away. * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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