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Combretastatin A-4
Combretastatin A-4 is a combretastatin and a stilbenoid. It can be isolated from '' Combretum caffrum'', the Eastern Cape South African bushwillow tree or in '' Combretum leprosum'', the mofumbo, a species found in Brazil. Function Tubulin represents a potent target in cancer chemotherapy, given its role in cell division. Combretastatin is a naturally occurring well known tubulin polymerization inhibitor. Combretastatin A-4 comes in two stereoisomers (cis (shown top right), and trans); The cis form binds much better to the 'colchicine' site on tubulin to inhibit polymerization. Derivatives Combretastatin A-4 is the active component of combretastatin A-4 phosphate, a prodrug designed to damage the vasculature (blood vessels) of cancer tumors causing central necrosis. A large number of synthetic derivatives have been reported, including beta-lactam A beta-lactam (β-lactam) ring is a four-membered lactam. A ''lactam'' is a cyclic amide, and ''beta''-lactams are named so be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combretastatin
Combretastatin is a dihydrostilbenoid found in '' Combretum caffrum''. As a class Combretastatins are a class of natural phenols. A variety of different natural combretastatin molecules are present in the bark of '' Combretum caffrum'', commonly known as South African Bush Willow. Despite having a similar name, combretastatins are unrelated to statins, a family of cholesterol lowering drugs. Natural combretastatins Molecules that fall into the combretastatin family generally share 3 common structural features: a trimethoxy "A"-ring, a "B"-ring containing substituents often at C3' and C4', and ftenan ethene bridge between the two rings which provides necessary structural rigidity. Molecules with such an ethene bridge are also stilbenoids, molecules with a non-ethene bridge are dihydrostilbenoids. Molecules with C3' amino and hydroxyl substituents are very active, and molecules with C4' hydroxyl or methoxy substituents are also cytotoxic. Of the natural products presently kn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stilbenoid
Stilbenoids are hydroxylated derivatives of stilbene. They have a C6–C2–C6 structure. In biochemical terms, they belong to the family of phenylpropanoids and share most of their biosynthesis pathway with chalcones. Most stilbenoids are produced by plants, and the only known exception is the antihelminthic and antimicrobial stilbenoid, 2-isopropyl-5- ''E'')-2-phenylvinylenzene-1,3-diol, biosynthesized by the Gram-negative bacterium '' Photorhabdus luminescens.'' Chemistry Stilbenoids are hydroxylated derivatives of stilbene and have a C6–C2–C6 structure. They belong to the family of phenylpropanoids and share most of their biosynthesis pathway with chalcones. Under UV irradiation, stilbene and its derivatives undergo intramolecular cyclization, called stilbene photocyclization to form dihydrophenanthrenes. Oligomeric forms are known as oligostilbenoids. Types ;Aglycones * Piceatannol in the roots of Norway spruces * Pinosylvin is a fungal toxin protecting wood f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combretum Caffrum
''Combretum caffrum'' is the Eastern Cape South African bushwillow tree. Biochemistry In ''C. caffrum'', combretastatins A-1, A-4 and B-1 can be found. References * * caffrum[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combretum Leprosum
''Combretum leprosum'', the mofumbo in Portuguese and the asucaró in eastern Bolivian Spanish, is a plant species in the genus ''Combretum ''Combretum'', the bushwillows or combretums, make up the type genus of the family Combretaceae. The genus comprises about 272 species of trees and shrubs, most of which are native to tropical and southern Africa, about 5 to Madagascar, but th ...'' found throughout the Amazon Basin. This plant contains combretastatin A-4. In many areas of the eastern Bolivian countryside, people have traditionally maintained specimens of these trees and encouraged their proliferation because they are perceived to be useful providers of shade. References External links leprosum Flora of Brazil Plants described in 1841 {{Myrtales-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tubulin
Tubulin in molecular biology can refer either to the tubulin protein superfamily of globular proteins, or one of the member proteins of that superfamily. α- and β-tubulins polymerize into microtubules, a major component of the eukaryotic cytoskeleton. Microtubules function in many essential cellular processes, including mitosis. Tubulin-binding drugs kill cancerous cells by inhibiting microtubule dynamics, which are required for DNA segregation and therefore cell division. In eukaryotes, there are six members of the tubulin superfamily, although not all are present in all species.Turk E, Wills AA, Kwon T, Sedzinski J, Wallingford JB, Stearns "Zeta-Tubulin Is a Member of a Conserved Tubulin Module and Is a Component of the Centriolar Basal Foot in Multiciliated Cells"Current Biology (2015) 25:2177-2183. Both α and β tubulins have a mass of around 50 kDa and are thus in a similar range compared to actin (with a mass of ~42 kDa). In contrast, tubulin polymers (microtubules) te ... [...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 targets, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stereoisomer
In stereochemistry, stereoisomerism, or spatial isomerism, is a form of isomerism in which molecules have the same molecular formula and sequence of bonded atoms (constitution), but differ in the three-dimensional orientations of their atoms in space. This contrasts with structural isomers, which share the same molecular formula, but the bond connections or their order differs. By definition, molecules that are stereoisomers of each other represent the same structural isomer. Enantiomers Enantiomers, also known as optical isomers, are two stereoisomers that are related to each other by a reflection: they are mirror images of each other that are non-superposable. Human hands are a macroscopic analog of this. Every stereogenic center in one has the opposite configuration in the other. Two compounds that are enantiomers of each other have the same physical properties, except for the direction in which they rotate polarized light and how they interact with different optical isom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cis–trans Isomerism
''Cis''–''trans'' isomerism, also known as geometric isomerism or configurational isomerism, is a term used in chemistry that concerns the spatial arrangement of atoms within molecules. The prefixes "''cis''" and "''trans''" are from Latin: "this side of" and "the other side of", respectively. In the context of chemistry, ''cis'' indicates that the functional groups (substituents) are on the same side of some plane, while ''trans'' conveys that they are on opposing (transverse) sides. ''Cis''–''trans'' isomers are stereoisomers, that is, pairs of molecules which have the same formula but whose functional groups are in different orientations in three-dimensional space. ''Cis-trans'' notation does not always correspond to E–Z notation, ''E''–''Z'' isomerism, which is an ''Absolute configuration, absolute'' stereochemical description. In general, ''cis''–''trans'' stereoisomers contain double bonds that do not rotate, or they may contain ring structures, where the rotation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Combretastatin A-4 Phosphate
Fosbretabulin (also known as combretastatin A-4 phosphate or CA4P) is a microtubule destabilizing experimental drug, a type of vascular-targeting agent, a drug designed to damage the vasculature (blood vessels) of cancer tumours causing central necrosis. It is a derivative of combretastatin. It is formulated as the salts fosbretabulin disodium and fosbretabulin tromethamine. Fosbretabulin is a prodrug. ''In vivo'', it is dephosphorylated to its active metabolite, combretastatin A-4. In July 2007, the pharmaceutical company OXiGENE initiated a 180-patient phase III clinical trial of fosbretabulin in combination with carboplatin for the treatment of anaplastic thyroid cancer. There is currently no fully FDA approved treatment for this form of cancer. By 2017, it had completed multiple clinical trials (e.g. for solid tumours, non-small cell lung cancer) with more in progress. See also * Combretastatin Combretastatin is a dihydrostilbenoid found in '' Combretum caffrum''. As ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenols And Polyphenols Derivative
In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of one or more hydroxyl groups (— O H) bonded directly to an aromatic hydrocarbon group. The simplest is phenol, . Phenolic compounds are classified as simple phenols or polyphenols based on the number of phenol units in the molecule. Phenols are both synthesized industrially and produced by plants and microorganisms. Properties Acidity Phenols are more acidic than typical alcohols. The acidity of the hydroxyl group in phenols is commonly intermediate between that of aliphatic alcohols and carboxylic acids (their pKa is usually between 10 and 12). Deprotonation of a phenol forms a corresponding negative phenolate ion or phenoxide ion, and the corresponding salts are called phenolates or phenoxides (aryloxides according to the IUPAC Gold Book). Condensation with aldehydes and ketones Phenols are susceptible to Electrophilic aromatic substitutions. Condensation with formald ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta-lactam
A beta-lactam (β-lactam) ring is a four-membered lactam. A ''lactam'' is a cyclic amide, and ''beta''-lactams are named so because the nitrogen atom is attached to the β-carbon atom relative to the carbonyl. The simplest β-lactam possible is 2-azetidinone. β-lactams are significant structural units of medicines as manifested in many β-lactam antibiotics Up to 1970, most β-lactam research was concerned with the penicillin and cephalosporin groups, but since then, a wide variety of structures have been described. Clinical significance The β-lactam ring is part of the core structure of several antibiotic families, the principal ones being the penicillins, cephalosporins, carbapenems, and monobactams, which are, therefore, also called β-lactam antibiotics. Nearly all of these antibiotics work by inhibiting bacterial cell wall biosynthesis. This has a lethal effect on bacteria, although any given bacteria population will typically contain a subgroup that is resistant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ombrabulin
Ombrabulin was an experimental drug candidate discovered by Ajinomoto and further developed by Sanofi-Aventis. Ombrabulin is a combretastatin A-4 derivative that exerts its antitumor effect by disrupting the formation of blood vessels needed for tumor growth. It was granted orphan drug status by the European Medicines Agency The European Medicines Agency (EMA) is an agency of the European Union (EU) in charge of the evaluation and supervision of medicinal products. Prior to 2004, it was known as the European Agency for the Evaluation of Medicinal Products or Euro ... in April 2011. In January 2013, Sanofi said it discontinued development of ombrabulin after disappointing results from phase III clinical trials. References {{reflist Experimental cancer drugs Amino acid derivatives ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
