| 词条 | Tellurocysteine |
| 释义 |
| ImageFile = L-tellurocysteine-2D-skeletal.png | ImageSize = 180px | ImageAlt = | IUPACName = (2R)-2-Amino-3-tellanylpropanoic acid | OtherNames = Tellurocystine | Section1 = {{Chembox Identifiers | CASNo = | PubChem = 129631934 | ChemSpiderID = 34500822 | StdInChI = 1S/C3H7NO2Te/c4-2(1-7)3(5)6/h2,7H,1,4H2,(H,5,6) | StdInChIKey = PRMLZSRTFWAUAH-UHFFFAOYSA-N | SMILES = C(C(C(=O)O)N)[TeH] | Section2 = {{Chembox Properties | C=3|H=7|N=1|O=2|Te=1 | Appearance = | Density = | MeltingPt = | BoilingPt = | Solubility = | Section3 = {{Chembox Hazards | MainHazards = | FlashPt = | AutoignitionPt = }} Tellurocysteine (in some publications referred to as Te-Cys) is an amino acid analogous to cysteine and selenocysteine with tellurium in place of sulfur or selenium in its side chain. It is not naturally found in organisms. PropertiesPerhaps due to its low bond energy with carbon (200 kJ/mol compared to 234 kJ/mol for selenium, or 272 kJ/mol for sulfur),[1] tellurocysteine is not present in any known natural organisms and is hence relatively understudied in comparison to selenocysteine.[2] Despite so, certain organisms such as fungi Aspergillus fumigatus is capable of incorporating tellurocysteine and telluromethionine into amino acids and proteins when exposed to a sulfur-free environment.[3] It has been observed that when incorporated into glutathione transferase, tellurocysteine efficiently inhibited aminoacylation and increased the efficiency of glutathione peroxidase.[4] SynthesisL-Tellurocysteine has been prepared from elemental tellurium by first reacting it with methyl (2R)-2-[(tert-butoxycarbonyl)amino]-3-iodopropionate in a tetrahydrofuran solvent with presence of lithium triethylborohydride, yielding a red oil which is acidified and treated with alkali before a treatment with citric acid to set its pH to 4.0, resulting in an orange solid after filtering and drying.[5]References1. ^{{cite journal|last1=Chivers|first1=Tristram|last2=Laitinen|first2=Risto S.|title=Tellurium: a maverick among the chalcogens|journal=Chemical Society Reviews|date=23 March 2015|volume=44|issue=7|pages=1725–1739|doi=10.1039/C4CS00434E|pmid=25692398|url=http://pubs.rsc.org/en/content/articlepdf/2015/CS/C4CS00434E|language=en|issn=1460-4744}} 2. ^{{cite book|title=Advances in Microbial Physiology|date=2007|publisher=Academic Press|isbn=9780080560649|page=4|url=https://books.google.com/books?id=1G95oJ1JONIC&pg=PA4|language=en}} 3. ^{{cite journal|last1=Ramadan|first1=ShadiaE.|last2=Razak|first2=A.A.|last3=Ragab|first3=A.M.|last4=El-Meleigy|first4=M.|title=Incorporation of tellurium into amino acids and proteins in a tellurium-tolerant fungi|journal=Biological Trace Element Research|date=1 June 1989|volume=20|issue=3|pages=225–232|doi=10.1007/BF02917437|language=English|issn=0163-4984}} 4. ^{{cite journal|last1=Liu|first1=Xiaoman|last2=Silks|first2=Louis A.|last3=Liu|first3=Cuiping|last4=Ollivault-Shiflett|first4=Morgane|last5=Huang|first5=Xin|last6=Li|first6=Jing|last7=Luo|first7=Guimin|last8=Hou|first8=Ya-Ming|last9=Liu|first9=Junqiu|last10=Shen|first10=Jiacong|title=Incorporation of Tellurocysteine into Glutathione Transferase Generates High Glutathione Peroxidase Efficiency|journal=Angewandte Chemie International Edition|date=2 March 2009|volume=48|issue=11|pages=2020–2023|doi=10.1002/anie.200805365|pmid=19199319}} 5. ^{{cite journal|last1=Stocking|first1=Emily M.|last2=Schwarz|first2=Jessie N.|last3=Senn|first3=Hans|last4=Salzmann|first4=Michael|last5=Silks|first5=Louis A.|title=Synthesis of L-selenocystine,L-[77Se]selenocystine andL-tellurocystine|journal=Journal of the Chemical Society, Perkin Transactions 1|date=1 January 1997|volume=0|issue=16|pages=2443–2448|doi=10.1039/A600180G|url=http://pubs.rsc.org/en/content/articlepdf/1997/p1/a600180g|accessdate=30 November 2017|language=en|issn=1364-5463}} 2 : Amino acids|Organotellurium compounds |
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