In chemistry , an oligomer is a molecule that consists of a few monomer units , or oligos, is Greek for a few , in contrast to a polymer that, at least in principle, consists of an unlimited number of monomers. ref http goldbook.iupac.org O04286.html IUPAC Goldbook Oligomer molecule ref Dimer chemistry Dimer s, Trimer chemistry trimer s, and tetramer s are oligomers. Many oils are oligomeric, such as Liquid paraffin medicinal liquid paraffin . Plasticizers are oligomeric ester s widely used to soften thermoplastics such as polyvinyl chloride PVC . They may be made from monomer s by linking them together, or by separation from the higher fractions of crude oil . Polybutene is an oligomeric oil used to make putty . Greek prefixes are often used to designate the number of monomer units in the oligomer, for example a tetramer being composed of four units and a hexamer of six. In biochemistry , the term oligomer or, informally, oligo is used for short, single stranded nucleic acid fragments, such as deoxyribonucleic acid DNA or ribonucleic acid RNA , or similar fragments of analogs of nucleic acids such as peptide nucleic acid or Morpholino s. Such oligos are used in hybridisation molecular biology hybridization experiments bound to glass slides or nylon membranes , as probes for in situ hybridization or in antisense experiments such as gene knockdown s. citation needed date April ..., a complex made of several different protein subunits is called a hetero oligomer or heteromer . When only one type of protein subunit is used in the complex, it is called a homo oligomer or homomer ... July 2010 When an oligomer forms as a result of chain transfer the oligomer is called a telomer ... Category Oligomers Category DNA Category Proteins ar cs Oligomer de Oligomer et Oligomeer es Olig mero fr Oligom re id Oligomer it Oligomero he hu Oligomer nl Oligomeer ja pl Oligomery pt Olig mero ru sl Oligomer sr Oligomer fi Oligomeeri sv Oligomer tr Oligomer ... more details
Oligomer Restriction abbreviated OR is a procedure to detect an Genetic polymorphism altered DNA sequence in a genome . A labeled oligonucleotide Hybridization probe probe is Nucleic acid hybridization hybridized to a target DNA, and then treated with a restriction enzyme . If the probe exactly matches the target, the restriction enzyme will cleave the probe, changing its size. If, however, the target DNA does not exactly match the probe, the restriction enzyme will have no effect on the length of the probe. The OR technique, now rarely performed, was closely associated with the development of the popular polymerase chain reaction PCR method. Image ORDemo.gif thumb right 450px center Mechanism of Oligomer Restriction. center Example In part 1a of the schematic the oligonucleotide probe, labeled on its left end asterisk , is shown on the top line. It is fully complementary to its target DNA here taken from the Human globin locus human hemoglobin gene , as shown on the next line. Part of the probe includes the Recognition site for the restriction enzyme Dde I underlined . In part 1b, the restriction enzyme has cleaved the probe and its target Dde I leaves three bases unpaired at each end . The labeled end of the probe is now just 8 bases in length, and is easily separated by Gel electrophoresis from the uncut probe, which was 40 bases long. In part 2, the same probe is shown hybridized to a target DNA which includes a single base mutation here the mutation responsible for Sickle Cell Anemia , or SCA . The mismatched hybrid no longer acts as a recognition site for the restriction enzyme, and the probe remains at its original length. History The Oligomer Restriction technique was developed as a variation of the Restriction Fragment Length Polymorphism RFLP assay method, with the hope of avoiding the laborious Southern blot ting step used in RFLP analysis. OR was conceived ... probes Nature vol. 324 6093 pp. 163 166 1986 . ref Problems The Oligomer Restriction method was beset ... more details
Ampelopsin may refer to Ampelopsin , a flavanonol Ampelopsin A , a stibene oligomer ref name Oshima Cite doi 10.1016 S0040 4020 01 87819 4 ref ref name Takaya Cite doi 10.1016 S0040 4020 02 00785 8 ref Ampelopsin B , a stibene oligomer ref name Oshima ref name Takaya Ampelopsin C , a stibene oligomer ref name Oshima Ampelopsin D , a stilbene oligomer ref name Takaya ref name Takaya Ampelopsin E , a stibene oligomer ref Cite PMID 21881241 ref Ampelopsin F , a stibene oligomer ref name Takaya ref http pubchem.ncbi.nlm.nih.gov summary summary.cgi?cid 484755&loc ec rcs Ampelopsin F on PubChem ref References Reflist Chemistry disambiguation ... more details
A decamer is an oligomer composed of 10 number ten sub unit s. See also wiktionary decamer Decameron disambiguation deca , a prefix mer , an affix chemistry stub Category Oligomers ... more details
Viniferin may refer to Alpha viniferin , a resveratrol trimer Beta viniferin , a resveratrol cyclic tetramer Delta viniferin , a resveratrol dehydrodimer Epsilon viniferin , a resveratrol dimer Gamma viniferin , a more highly polymerised oligomer of resveratrol R Viniferin , a synonym for the stilbenoid vitisin B R2 Viniferin , a synonym for the stilbenoid vitisin A chemistry disambiguation zh ... more details
The molecular formula C sub 28 sub H sub 22 sub O sub 6 sub molar mass 454.47 g mol, exact mass 454.141638 u may refer to Ampelopsin B , a stilbene oligomer Delta viniferin , a resveratrol dimer Epsilon viniferin , a resveratrol dimer Pallidol , a resveratrol dimer MolFormDisambig ... more details
In structural biology , a protomer is the structural unit of an oligomeric protein . A protomer can be a protein subunit or several different subunits, that assemble in a defined stoichiometry to form an oligomer . The protomer is the smallest subset of different subunits that form the oligomer. The protomers usually arrange in cyclic symmetry to form closed point group symmetries . Protomers are the main subunit in a viral capsid . br Examples br Different polypeptide chains protein subunits are conventionally designated by Greek letters. The number of each subunit in the oligomeric complex is indicated by the subscript number, similar to a chemical formula of a compound consisting of elements. Hemoglobin consists of two chains and two chains. The oligomer stoichiometry is thus sub 2 sub sub 2 sub . Hemoglobin is a heterotetramer consisting of four subunits two and two . It is a dimer of two protomers. Aspartate carbamoyltransferase has a sub 6 sub sub 6 sub subunit composition. The six protomers are arranged in D sub 3 sub symmetry. enzyme stub Category Structural biology Category Polymer chemistry es Prot mero fr Protom re ... more details
An end group in polymer chemistry is a constitutional unit that is an extremity of a macromolecule or oligomer molecule. For example the end group of a PET polyester may be an alcohol group or a carboxylic acid group. End groups in macromolecules may have special reactivity in follow up reactions, see graft copolymer s, or end groups can be used to determine molar mass . References IUPAC recommendations Category polymer chemistry ar ... more details
Dimer may refer to Dimer chemistry , a chemical structure formed from two sub units Dimer model , an item in statistical mechanics Protein dimer , a protein quaternary structure Julius Dimer 1871 1945 , a German chess master Dimerous refers to plants with organ arrangement based on the number 2 see merosity . See also Di disambiguation , a prefix mer , a suffix Oligomer Disambig es D mero sr ... more details
Orphan date November 2006 Context date October 2009 For the dietary behaviour term, see polyphagy . Polyphage are genomic Oligomer multimers of bacteriophage in which multiple viral particles are all encapsulated, one after the other, within the same set of coat proteins. This phenomenon is characteristic of filamentous phage . ref cite journal last Lopez first J coauthors Webster, RE title Morphogenesis of filamentous bacteriophage f1 orientation of extrusion and production of polyphage. journal Virology date 1983 May volume 127 issue 1 pages 177 93 pmid 6858000 ref References reflist Category Bacteriophages Category Microbiology bacteria stub ... more details
Multiple issues cleanup April 2009 refimprove April 2009 orphan January 2011 In polymer chemistry, in situ means in the polymerization mixture. There are numerous unstable oligomer s molecule s which must be synthesized in situ i.e. in the reaction mixture but cannot be isolated on their own for use in various processes. Example of this method include urea formaldehyde UF and melamine formaldehyde MF encapsulation systems.In such type of in situ polymerization a chemical encapsulation technique is involved very similar to interfacial coating. The distinguishing characteristic of in situ polymerization is that no reactants are included in the core material. All polymerization occurs in the continuous phase, rather than on both sides of the interface between the continuous phase and the core material. Category Polymers Polymer stub ... more details
Dicdef Multiple issues prose May 2011 unreferenced October 2010 notability May 2011 Other uses Mer disambiguation Mer wiktionarypar mer mer and mer from Greek meros , part are affix es used in the following words. Chemistry or biochemistry Monomer Dimer Trimer Tetramer Pentamer Hexamer Heptamer Octamer Nonamer Decamer Dodecamer Oligomer Polymer Enantiomer Heteromer Homeomer Isomer Biology Merosity , a characteristic regarding the flower petals number in plants Metamery , a characteristic of segmented animals DEFAULTSORT mer Category suffixes Category prefixes de mer vocab stub chem stub ... more details
enzyme Name 6 aminohexanoate dimer hydrolase EC number 3.5.1.46 CAS number 75216 15 8 IUBMB EC number 3 5 1 46 GO code 0019875 image width caption In enzymology , a 6 aminohexanoate dimer hydrolase EC number 3.5.1.46 is an enzyme that catalysis catalyzes the chemical reaction N 6 aminohexanoyl 6 aminohexanoate H sub 2 sub O math rightleftharpoons math 2 6 aminohexanoate Thus, the two substrate biochemistry substrates of this enzyme are N 6 aminohexanoyl 6 aminohexanoate and water H sub 2 sub O , whereas its product chemistry product is 6 aminohexanoate . This enzyme belongs to the family of hydrolase s, those acting on carbon nitrogen bonds other than peptide bonds, specifically in linear amides. The systematic name of this enzyme class is N 6 aminohexanoyl 6 aminohexanoate amidohydrolase . This enzyme is also called 6 aminohexanoic acid oligomer hydrolase . Structural studies As of late 2007, 3 tertiary structure structures have been solved for this class of enzymes, with Protein Data Bank PDB accession codes PDB link 1WYB , PDB link 1WYC , and PDB link 2DCF . See also Nylon eating bacteria References cite journal author Okada H date 1981 title Purification and characterization of 6 aminohexanoic acid oligomer hydrolase of Flavobacterium sp. Ki72 journal Eur. J. Biochem. volume 116 pages 547&ndash 51 pmid 7262074 doi 10.1111 j.1432 1033.1981.tb05371.x last2 Terada first2 T last3 Taniguchi first3 T last4 Takene first4 Y last5 Masuda first5 S last6 Matsunaga first6 N last7 Okada first7 H issue 3 Gene Ontology GO codes hydrolase stub Category EC 3.5.1 Category Enzymes of known structure ... more details
Telomerization is a radical polymerization Chemical reaction reaction where a chain transfer limits the size of the oligomer molecule Product chemistry product the telomer . ref GoldBookRef title telomerization file T06260 ref ref name Leh cite journal last Lehmler first HJ title Synthesis of environmentally relevant fluorinated surfactants a review journal Chemosphere volume 58 issue 11 pages 1471 96 date Mar 2005 doi 10.1016 j.chemosphere.2004.11.078 pmid 15694468 accessdate 2008 12 28 pmc 2587313 ref Telomerization requires a telogen to react with at least one Unsaturated compound unsaturated taxogen molecule. ref name Leh Fluorotelomer s are an example. See also Perfluorooctanoic acid Synthesis Perfluorooctanoic acid synthesis Telomerization dimerization References reflist Category Chemical synthesis Category Chemical processes Category Industrial processes Category Polymer chemistry reaction stub de Telomerisation Polymerisation et Telomerisatsioon fr T lom risation polym risation ... more details
wiktionary An oligoester is an ester oligomer chain containing a small number of repeating ester units monomer s . ref cite journal doi 10.1039 b816648j title Solid phase synthesis of a library of linear oligoester ion channels year 2009 last1 Fyles first1 Thomas Murray last2 Luong first2 Horace journal Organic & Biomolecular Chemistry volume 7 issue 4 pages 725 ref Oligoesters are short analog chemistry analogs of polymeric polyester s. An example is oligo R 3 hydroxybutyrate. ref name Xian cite journal author Xian M, Fuerst MM, Shabalin Y, Reusch RN title Sorting signal of Escheria coli OmpA is modified by oligo R 3 hydroxybutyrate journal Biochim Biophys Acta. month Nov year 2007 volume 1768 issue 11 pages 2660 6 url doi 10.1016 j.bbamem.2007.06.019 pmid 17659252 pmc 2266070 ref See also Oligopeptide References reflist Category Carboxylate esters Category Polyesters organic chem stub ... more details
A telechelic polymer or oligomer is a prepolymer capable of entering into further polymerization or other reactions through its reactive end groups ref http goldbook.iupac.org TT07167.html ref . It can be used for example to synthesize block copolymer s. By definition, a telechelic polymer is a di end functional polymer where both ends possess the same functionality. ref Moad, G. Solomon, D. H. The Chemistry of Radical Polymerisation, 2nd Ed., Elsevier, 2006, page 374 ref Where the chain ends of the polymer are not of the same functionality they are termed di end functional polymers. All polymers resulting from living polymerization are end functional but may not necessarily be telechelic. ref Moad, G. Solomon, D. H. The Chemistry of Radical Polymerisation, 2nd Ed., Elsevier, 2006, chapter 9 onwards ref To prepare polymers by step growth polymerization , telechelic polymers like Polyol Polyols in polymer chemistry polymeric diols and epoxy prepolymers can be used. The main examples are Polyether diols Polyester diols Polycarbonate diols Polyhexamethylene carbonate diol PHMCD Polyalcadiene diols Hydroxyl terminated polybutadiene PBHT ... Other examples of telechelic polymers are the halato telechelic polymers or halatopolymers ref http goldbook.iupac.org HT07207.html ref . The end groups of these polymers are ionic or ionizable like carboxylate or quaternary ammonium groups. References references DEFAULTSORT Telechelic Polymer Category Polymers Chemistry stub ... more details
DISPLAYTITLE k mer unreferenced date May 2010 The term k mer or x mer where x can be virtually any consonant of choice usually refers to a specific n tuple or n gram of nucleic acid or amino acid sequence s that can be used to identify certain regions within biomolecules like DNA e.g. for gene prediction or proteins. Either k mer strings as such can be used for finding regions of interest, or k mer statistics giving discrete probability distribution s of a number of possible k mer combination s or rather permutation s with repetitions are used. Specific short k mers are called oligomer s or oligos for short. Applications In algorithms for Sequence assembly In algorithms for Sequence alignment See also polymer N gram N tuple lattice models Examples A sequence of dimers AGAGAGAGAGAGAG A sequence of trimers AAGAAGAAGAAG External links http generegulation.info index.php?option com content&view article&id 47&Itemid 64 Lattice models for protein DNA binding Category Nucleic acids Category Applied mathematics Category Biophysics Category Computational biology Category Bioinformatics Category Amino acids Chem stub ... more details
The company Heliatek was spun off in July 2006 from the Technical University of Dresden IAPP and the University of Ulm . ref http www.chemeurope.com en companies 22911 heliatek gmbh.html ChemEurope report ref The company s founding brought together internationally renowned expertise in the fields of organic optoelectronics and organic oligomer synthesis. Among related fields of operation, the company wants to be instrumental in establishing environmentally friendly solar energy as a widespread, commonplace technology. In 2011 the company was recognized, by an audience other than professionals in the field, for winning the German Future Prize . ref http ecosummit.net articles tag heliatek EcoSummit Berlin ref ref http www.energyharvestingjournal.com articles heliatek achieves new world record for organic solar cells 00003979.asp?sessionid 1 Energy Harvesting Journal ref See also Can Heliatek Get Organic PV to Market? http www.greentechmedia.com articles read can heliatek get organic pv to market Heliatek achieves new world record for organic solar cells http www.printedelectronicsworld.com articles heliatek achieves new world record for organic solar cells 00003981.asp?sessionid 1 References reflist Category Solar energy companies Category Optoelectronics ... more details
Polybutene and polyisobutylene are liquid oligomer s widely used as plasticizers for high molecular weight polymer s, such as polyethylene . They are not to be confused with the high molecular weight polymer polybutene 1 . Properties The liquid is clear and colourless, and is sold in many different grades. The grades are determined mainly by molecular weight , with the higher molecular weight grades having increasing viscosity . The oligomer degrades at high temperature upwards of 350 C to form monomer isobutene by chains unzipping from the chain ends. Production Polybutene is similar to but different from polyisobutylene PIB . Polybutene is typically made from cat cracker mixed C4s after the stream is Merox treated to remove sulfur and amines, and contain 1 butene , 2 butene , and isobutylene . Ethylene steam cracker C4s are also used as supplemental feed for polybutene. On the other hand, PIB is produced from essentially pure isobutylene made in a C4 complex of a major refinery. The presence of isomers other than isobutylene can have several effects including 1 lower reactivity due to steric hindrance at the terminal carbon in, e.g., manufacture of polyisobutenyl succinic anhydride PIBSA dispersant manufacture 2 the molecular weight viscosity relationships of the two materials may also be somewhat different. The reaction is an acid catalyzed carbocationic polymerization typically using aluminum chloride or hydrogen halide acid such as HF. So called high reactivity polybutene or PIB is produced using purified isobutylene feedstock and strong acid catalyst such as HF or HF with promoter. Structure The repeat unit is in case of 1 butene CH sub 2 sub CH CH sub 2 sub CH sub 3 sub sub n sub The repeat unit in case of 2 butene is CH CH sub 3 sub CH CH sub 3 sub sub n sub One of the end units in the polymer chain contains a double bond, allowing reactivity with other compounds to provide functional chemistry mainly for lubricant additives for engine oils, fuels, and greases ... more details
About the chemistry term the audio engineering term dynamic range compression Side chaining In organic chemistry and biochemistry , a side chain is a Substituent chemical group that is attached to a core part of the molecule called main chain or Backbone chain backbone . The placeholder R is often used as a generic placeholder for alkyl saturated hydrocarbon group side chains in chemical structure diagrams. To indicate other non carbon groups in structure diagrams, X , Y , or Z is often used. The R , historically, is derived from radical chemistry radical or rest . Citation needed date January 2011 In polymer science, the side chain or pendant chain is oligomer ic or polymeric offshoot extends from the backbone chain of a polymer. Side chains have noteworthy influence on a polymer s properties, mainly its polymer Crystallinity crystallinity and density . An oligomeric branch may be termed a short chain branch and a polymeric branch may be termed a long chain branch. Pendant group Side groups are different from side chains they are neither oligomeric nor polymeric ref http goldbook.iupac.org B00720.html ref . In protein s composed of amino acid s the side chains are attached to the alpha carbon atoms of the amide backbone . See also Substituent Functional group Alkyl References reflist Category Organic chemistry Chemistry stub polymer stub ar ca Cadena lateral da Sidek de de Seitenkette et K rvalahel es Cadena lateral fr Cha ne lat rale pt Cadeia lateral sr Bo ni lanac zh ... more details
The Schlenk equilibrium is a chemical equilibrium named after its discoverer Wilhelm Schlenk taking place in solutions of Grignard reagent s. ref cite journal author W. Schlenk W. Schlenk, Jr. journal Chem. Ber. volume 62 issue 4 pages 920 year 1929 doi 10.1002 cber.19290620422 title ber die Konstitution der Grignardschen Magnesiumverbindungen ref ref Grignard Reagents New Developments H. G. Richey Editor ISBN 0 471 99908 3 ref 2 RMgX math overrightarrow leftarrow math MgX sub 2 sub MgR sub 2 sub The process described is an equilibrium between two equivalents of an alkyl or aryl magnesium halide on the left of the equation and on the right side, one equivalent of the di alkyl or di aryl magnesium compound and magnesium halide salt . Organomagnesium halides in solution also form Dimer chemistry dimers and higher oligomer s, especially at high concentration. Alkyl magnesium chlorides in ether are present as dimers. ref J. March Advanced Organic Chemistry 3rd Ed. ISBN 0471854727 ref The position of the equilibrium is influenced by solvent, temperature, and the nature of the various substituents. It is known that magnesium center in Grignard reagents typically coordinates two molecules of ether such as diethyl ether or tetrahydrofuran THF . Thus they are more precisely described as having the formula RMgXL sub 2 sub where L an ether. In the presence of monoethers, the equilibrium typically favors the alkyl or arylmagnesium halide. Addition of dioxane to such solutions, however, leads to selective precipitation of dihalide MgX sub 2 sub dioxane , driving the equilibrium completely to the right side of the equation. ref cite journal author Richard A. Andersen, Geoffrey Wilkinson title Bis Trimethylsilyl Methyl Magnesium journal Inorg. Synth. doi 10.1002 9780470132500.ch61 year 1979 volume 19 pages 262 ref The dialkylmagnesium compounds are potent alkylating agents and are popular in the synthesis of organometallic compounds. References reflist Category organometallic che ... more details
Unreferenced date December 2009 Orphan date February 2009 A Thiacalixarene is a macrocycle or Cyclic compound cyclic oligomer based on a condensation product of a phenol derivative and sulfur. The word thiacalixarene is derived from thia as sulfur and calixarene . Thiacalixarenes have hydrophobic cavities that can hold smaller molecules or ions and belong to the class of cavitand s known in Host guest chemistry . Thiacalixarene IUPAC nomenclature nomenclature is straightforward and involves counting the number of repeating unit s in the ring and include it in the name. A calix 4 arene has 4 units in the ring and a calix 6 arene has 6. Synthesis Thiacalixarenes are synthetized using phenol derivatives and sulfur. The chemical reaction ranks under electrophilic aromatic substitution s followed by an elimination of water and then a second aromatic substitution. The reaction is base chemistry base catalysed . Calixarenes are difficult to separate because it is all too easy to end up with complex mixtures of linear and cyclic oligomers with different numbers of repeating units. With finely tuned starting materials and reaction conditions synthesis can also be surprisingly easy. image Thiacalixarene.png center generic thiacalix n arene structure Structure Thiacalixarenes, like calixarene are characterised by a three dimensional basket vase or chalice shape . In thiacalix 4 arene derivatives, the internal volume is around 10 cubic nanometer s. Thiacalix 4 arenes are characterised by a wide upper rim and a narrow lower rim . With phenol as a starting material, the 4 hydroxyl groups are intrannular on the lower rim. The basket form cone conformation is stabilized by hydrogen bond ing between the four hydroxyl group. In case of substituted hydroxyl group, other conformers can be observed, like 1,2 or 1,3 alternate. image PtertbutylthiacalixareneStructure.png center p tert butylthiacalix 4 arene crystal structure a methanol molecule is hosted in the cavity . Category Macrocycl ... more details
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