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Taxoid
Taxoids are a class of derivatives from taxol, that is, paclitaxel. They were developed for their anticancer chemotherapeutic properties. Taxoids are usually treated as synonymous with taxanes; for example, a major medical dictionary defines the two terms with the same definition phrasing, and in another the phrasing varies slightly but conveys nearly identical meaning. Taxoids are chemically taxane-derived diterpenoid Diterpenes are a class of chemical compounds composed of four isoprene units, often with the molecular formula C20H32. They are biosynthesized by plants, animals and fungi via the HMG-CoA reductase pathway, with geranylgeranyl pyrophosphate being ...s, which do occur in nature, in the genera '' Taxus'' and '' Austrotaxus'' of yew trees. The taxoids class and the taxanes class both include paclitaxel (trade names Taxol, Abraxane, Onxol, Nov-Onxol) and docetaxel (trade names Taxotere, Docecad). References Mitotic inhibitors {{antineoplastic-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Docetaxel
Docetaxel (DTX or DXL), sold under the brand name Taxotere among others, is a chemotherapy medication used to treat a number of types of cancer. This includes breast cancer, head and neck cancer, stomach cancer, prostate cancer and non-small-cell lung cancer. It may be used by itself or along with other chemotherapy medication. It is given by slow injection into a vein. Common side effects include hair loss, cytopenia (low blood cell counts), numbness, shortness of breath, nausea, vomiting, and muscle pains. Other severe side effects include allergic reactions and future cancers. Docetaxel induced pneumotoxicity is also a well recognized adverse effect which has to be identified timely and treated after withholding the drug Side effects are more common in people with liver problems. Use during pregnancy may harm the baby. Docetaxel is in the taxane family of medications. It works by disrupting the normal function of microtubules and thereby stopping cell division. Docetaxel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxane
Taxanes are a class of diterpenes. They were originally identified from plants of the genus '' Taxus'' (yews), and feature a taxadiene core. Paclitaxel (Taxol) and docetaxel (Taxotere) are widely used as chemotherapy agents. Cabazitaxel was FDA approved to treat hormone-refractory prostate cancer. Taxanes present difficulties in formulation as medicines because they are poorly soluble in water. Production As their name suggests, taxanes were first derived from natural sources, but some have been semisynthesized. Paclitaxel was originally derived from the Pacific yew tree. Taxanes are difficult to synthesize because of their numerous chiral centres—taxol has 11 of these. Recently, the presence of taxanes in the shells and leaves of ''Corylus avellana'' (the common hazel plant) has been reported. Mechanism of action The principal mechanism of action of the taxane class of drugs is the disruption of microtubule function. Microtubules are essential to cell division, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paclitaxel
Paclitaxel (PTX), sold under the brand name Taxol among others, is a chemotherapy medication used to treat a number of types of cancer. This includes ovarian cancer, esophageal cancer, breast cancer, lung cancer, Kaposi's sarcoma, cervical cancer, and pancreatic cancer. It is administered by intravenous injection. There is also an albumin-bound formulation. Common side effects include hair loss, bone marrow suppression, numbness, allergic reactions, muscle pains, and diarrhea. Other serious side effects include heart problems, increased risk of infection, and lung inflammation. There are concerns that use during pregnancy may cause birth defects. Paclitaxel is in the taxane family of medications. It works by interference with the normal function of microtubules during cell division. Paclitaxel was first isolated in 1971 from the Pacific yew and approved for medical use in 1993. It is on the World Health Organization's List of Essential Medicines. It has been made ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemotherapy
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 tar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synonym
A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all synonyms of one another: they are ''synonymous''. The standard test for synonymy is substitution: one form can be replaced by another in a sentence without changing its meaning. Words are considered synonymous in only one particular sense: for example, ''long'' and ''extended'' in the context ''long time'' or ''extended time'' are synonymous, but ''long'' cannot be used in the phrase ''extended family''. Synonyms with exactly the same meaning share a seme or denotational sememe, whereas those with inexactly similar meanings share a broader denotational or connotational sememe and thus overlap within a semantic field. The former are sometimes called cognitive synonyms and the latter, near-synonyms, plesionyms or poecilonyms. Lexicograph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diterpenoid
Diterpenes are a class of chemical compounds composed of four isoprene units, often with the molecular formula C20H32. They are biosynthesized by plants, animals and fungi via the HMG-CoA reductase pathway, with geranylgeranyl pyrophosphate being a primary intermediate. Diterpenes form the basis for biologically important compounds such as retinol, retinal, and phytol. They are known to be antimicrobial and antiinflammatory. Structures As with most terpenes a huge number of potential structures exists, which may be broadly divided according to the number of rings present. Biosynthesis Diterpenes are derived from the addition of one IPP unit to FPP to form geranylgeranyl-pyrophosphate (GGPP). From GGPP, structural diversity is achieved mainly by two classes of enzymes; the diterpene synthases and cytochromes P450. Several diterpenes are produced by plants and cyanobacteria. GGPP is also the precursor for the synthesis of the phytane by the action of the enzyme geranyl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxus
''Taxus'' is a genus of coniferous trees or shrubs known as yews in the family Taxaceae. They are relatively slow-growing and can be very long-lived, and reach heights of , with trunk girth averaging . They have reddish bark, lanceolate, flat, dark-green leaves long and broad, arranged spirally on the stem, but with the leaf bases twisted to align the leaves in two flat rows either side of the stem. The oldest known fossil species are from the Early Cretaceous. Morphology The seed cones are highly modified, each cone containing a single seed long partly surrounded by a modified scale which develops into a soft, bright red berry-like structure called an aril, long and wide and open at the end. The arils are mature 6–9 months after pollination, and with the seed contained are eaten by thrushes, waxwings and other birds, which disperse the hard seeds undamaged in their droppings; maturation of the arils is spread over 2–3 months, increasing the chances of successful ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Austrotaxus
''Austrotaxus spicata'', the New Caledonia yew or southern yew, is a species of yew, the sole species in the genus ''Austrotaxus''. It is related to the other yews in the genera '' Taxus'' and '' Pseudotaxus''. It is endemic to New Caledonia, occurring in the central and northern parts of the island at 300-1,350 m altitude. It is a dioecious coniferous shrub or small tree, reaching 5–20 m (rarely 25 m) tall with reddish bark. The leaves are lanceolate, flat, 8–12 cm long (up to 17 cm on young plants) and 4 mm broad, dark green above, with two paler green stomatal bands below; they are arranged spirally on the stem. The seed cones are drupe-like, 20–25 mm long, with a fleshy aril An aril (pronounced ), also called an arillus, is a specialized outgrowth from a seed that partly or completely covers the seed. An arillode or false aril is sometimes distinguished: whereas an aril grows from the attachment point of the see ... almost completely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yew Tree
Yew is a common name given to various species of trees. It is most prominently given to any of various coniferous trees and shrubs in the genus '' Taxus'': * European yew or common yew ('' Taxus baccata'') * Pacific yew or western yew (''Taxus brevifolia'') * Canadian yew (''Taxus canadensis'') * Chinese yew (''Taxus chinensis'') * Japanese yew (''Taxus cuspidata'') * Florida yew (''Taxus floridana'') * Mexican yew ('' Taxus globosa'') * Sumatran yew (''Taxus sumatrana'') * Himalayan yew (''Taxus wallichiana'') * ''Taxus masonii'' (Eocene fossil yew) It is also used for any of various coniferous plants in the families Taxaceae and Cephalotaxaceae: * White-berry yew (''Pseudotaxus chienii'') * New Caledonian yew or southern yew (''Austrotaxus spicata'') * Catkin-yew (''Amentotaxus sp.'') * Plum-yew (''Cephalotaxus sp.'') Various coniferous plants in the family Podocarpaceae, superficially similar to other yews, are also known by this name: * Prince Albert's yew (''Saxegothaea c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
