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Abeotaxane
Abeotaxanes are a class of taxoid molecules with a core 5/7/6 type ring structure. This structure varies from the 6/8/6 or 6/10/6-membered core ring found in conventional taxoids such as paclitaxel or docetaxel. The core carbon skeleton of a normal natural product taxane (e.g., paclitaxel, docetaxel) has a 6-membered A ring, 8-membered B ring and a 6-membered C ring, combined with conventional side chains. It is the side chains that provide most of the activity for regular taxanes. Abeotaxanes are compounds containing 3 altered ring structures, where ring A is 5 members, ring B is 7 members and ring C is 6 members, combined with conventional side chains. Like taxanes, abeotaxanes are diterpenes produced by the yew tree (genus ''Taxus''). These agents inhibit the growth and replication of cancer cells by affecting microtubules Microtubules are polymers of tubulin that form part of the cytoskeleton and provide structure and shape to eukaryotic cells. Microtubules can be as long a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diterpenes
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 geranylger ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 diterpenoids, 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 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 ... (trade names Taxotere, Docecad). References Mitotic inhibitors {{antineoplastic-drug-stub ... [...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 from precu ... [...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. Docetaxe ... [...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 seed d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microtubules
Microtubules are polymers of tubulin that form part of the cytoskeleton and provide structure and shape to eukaryotic cells. Microtubules can be as long as 50 micrometres, as wide as 23 to 27 nm and have an inner diameter between 11 and 15 nm. They are formed by the polymerization of a dimer of two globular proteins, alpha and beta tubulin into protofilaments that can then associate laterally to form a hollow tube, the microtubule. The most common form of a microtubule consists of 13 protofilaments in the tubular arrangement. Microtubules play an important role in a number of cellular processes. They are involved in maintaining the structure of the cell and, together with microfilaments and intermediate filaments, they form the cytoskeleton. They also make up the internal structure of cilia and flagella. They provide platforms for intracellular transport and are involved in a variety of cellular processes, including the movement of secretory vesicles, organell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood–brain Barrier
The blood–brain barrier (BBB) is a highly selective semipermeable membrane, semipermeable border of endothelium, endothelial cells that prevents solutes in the circulating blood from ''non-selectively'' crossing into the extracellular fluid of the central nervous system where neurons reside. The blood–brain barrier is formed by endothelial cells of the Capillary, capillary wall, astrocyte end-feet ensheathing the capillary, and pericytes embedded in the capillary basement membrane. This system allows the passage of some small molecules by passive transport, passive diffusion, as well as the selective and active transport of various nutrients, ions, organic anions, and macromolecules such as glucose and amino acids that are crucial to neural function. The blood–brain barrier restricts the passage of pathogens, the diffusion of solutes in the blood, and Molecular mass, large or Hydrophile, hydrophilic molecules into the cerebrospinal fluid, while allowing the diffusion of Hydr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
