| 词条 | Biuret |
| 释义 |
| Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 455517063 | ImageFile = Biuret struct.svg | ImageFile_Ref = {{chemboximage|correct|??}} | ImageSize = 160 | ImageAlt = Skeletal formula of biuret | ImageFile1 = Biuret 3D ball.png | ImageFile1_Ref = {{chemboximage|correct|??}} | ImageSize1 = 160 | ImageAlt1 = Ball-and-stick model of the biuret molecule | ImageFile2 = Biuret-3D-vdW.png | ImageFile2_Ref = {{chemboximage|correct|??}} | ImageSize2 = 160 | ImageAlt2 = Space-filling model of the biuret molecule | PIN = 2-Imidodicarbonic diamide[1] | OtherNames = Biuret[1] Allophanamide[2] Carbamylurea[2] Allophanic acid amide[2] Allophanimidic acid[2] N-Carbamoylaminomethanamide{{citation needed|date=June 2012}} Ureidoformamide[2] Imidodicarbonic diamide{{citation needed|date=May 2012}} Diurea{{citation needed|date=January 2016}} |Section1={{Chembox Identifiers | CASNo = 108-19-0 | CASNo_Ref = {{cascite|correct|CAS}} | UNII_Ref = {{fdacite|changed|FDA}} | UNII = 89LJ369D1H | PubChem = 7913 | ChemSpiderID = 7625 | ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} | EINECS = 203-559-0 | KEGG = C06555 | KEGG_Ref = {{keggcite|correct|kegg}} | MeSHName = Biuret | ChEBI = 18138 | ChEBI_Ref = {{ebicite|correct|EBI}} | Beilstein = 1703510 | Gmelin = 49702 | 3DMet = B00969 | SMILES = NC(=O)NC(N)=O | StdInChI = 1S/C2H5N3O2/c3-1(6)5-2(4)7/h(H5,3,4,5,6,7) | StdInChI_Ref = {{stdinchicite|correct|chemspider}} | StdInChIKey = OHJMTUPIZMNBFR-UHFFFAOYSA-N | StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} }} |Section2={{Chembox Properties | C=2 | H=5 | N=3 | O=2 | Appearance = White crystals | Odor = Odourless | Density = 1.467 g/cm3 | MeltingPt = 190 °C (decomposes) }} |Section3={{Chembox Thermochemistry | DeltaHf = −565.8–−561.6 kJ mol−1 | DeltaHc = −940.1–−935.9 kJ mol−1 | Entropy = 146.1 J K−1 mol−1 | HeatCapacity = 131.3 J K−1 mol−1 }} |Section4={{Chembox Hazards | GHSPictograms = {{gHS exclamation mark}} | GHSSignalWord = WARNING | HPhrases = {{h-phrases|315|319|335}} | PPhrases = {{p-phrases|261|305+351+338}} }} |Section5={{Chembox Related | OtherCompounds =urea, triuret, cyanuric acid }} }}Biuret is a chemical compound with the chemical formula C2H5N3O2. It is also known as carbamylurea. It is the result of condensation of two molecules of urea and is an impurity in urea-based fertilizers. This white solid is soluble in hot water. Biuret was first prepared and studied by Gustav Heinrich Wiedemann (1826 - 1899) for his doctoral dissertation, which was submitted in 1847. His findings were reported in several articles.[3][4][5][6] The term "biuret" also describes a family of organic compounds with the functional group -(HN-CO-)2N-. Thus dimethyl biuret is CH3HN-CO-NR'-CO-NHCH3. A variety of organic derivatives are possible. PreparationThe parent compound can be prepared by heating urea above the melting point at which temperature ammonia is expelled:[7] 2 CO(NH2)2 → H2N-CO-NH-CO-NH2 + NH3 Under related conditions, pyrolysis of urea affords triuret ((H2N-CO-NH)2CO).[7] In general, organic biurets (those with alkyl or aryl groups in place of one or more H atoms) are prepared by trimerization of isocyanates. For example, the trimer of 1,6-hexamethylene diisocyanate is also known as HDI-biuret. ApplicationsBiuret is also used as a non-protein nitrogen source in ruminant feed,[8] where it is converted into protein by gut microorganisms.[9] It is less favored than urea, due to its higher cost and lower digestibility[10] but this characteristic also slows down its digestion and so decreases the risk of ammonia toxicity.[10][11] Biuret testThe biuret test is a chemical test for proteins and polypeptides. It is based on the biuret reagent, a blue solution that turns violet upon contact with proteins, or any substance with peptide bonds. The test and reagent do not actually contain biuret; they are so named because both biuret and proteins have the same response to the test. Related compounds
References1. ^1 {{cite book | title = Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book) | publisher = The Royal Society of Chemistry | date = 2014 | location = Cambridge | page = 866 | doi = 10.1039/9781849733069 | isbn = 978-0-85404-182-4}} 2. ^1 2 3 4 Scifinder, version 2007.1; Chemical Abstracts Service: Columbus, OH; RN 108-19-0 (accessed June 15, 2012) 3. ^{{ cite journal | author = Wiedemann, G. | title = Ueber ein neues Zersetzungsproduct des Harnstoffs |trans-title=On a new decomposition product of urea | journal = Annalen der Physik | volume = 150 | issue = 5 | pages = 67–84 | year = 1848 | doi = 10.1002/andp.18491500508 }} 4. ^{{ cite journal | author = Wiedemann, G. | title = Neues Zersetzungsproduct des Harnstoffs |trans-title=New decomposition product of urea | journal = Journal für Praktische Chemie | year = 1847 | volume = 42 | issue = 3–4 | pages = 255–256 | url = https://books.google.com/books?id=WNQPAAAAQAAJ&pg=PA255 | doi = 10.1002/prac.18470420134 }} This notice reports that biuret reacts with alkaline copper sulfate to produce a red solution -- the so-called "Biuret test" 5. ^{{ cite journal | author = Wiedemann, G. | title = Ueber eine neue, aus dem Harnstoff entstehende Verbindung |trans-title=On a new compound arising from urea | journal = Journal für Praktische Chemie | year = 1848 | volume = 43 | issue = 5 | pages = 271–280 | doi = 10.1002/prac.18480430133 | url = https://books.google.com/books?id=hgYwAAAAIAAJ&pg=PA271 }} 6. ^{{ cite journal | author = Wiedemann, G. | year = 1848 | title = Biuret. Zersetzungsprodukt des Harnstoffs |trans-title=Biuret: decomposition product of urea | journal = Justus Liebig's Annalen der Chemie | volume = 68 | issue = 3 | pages = 323–326 | doi = 10.1002/jlac.18480680318 }} 7. ^1 {{ Ullmann | author = Meessen, J. H. | author2 = Petersen, H. | title = Urea | doi = 10.1002/14356007.a27_333 }} 8. ^Beef cattle feed, Encyclopædia Britannica Online 9. ^{{ cite web | url = http://edis.ifas.ufl.edu/AN117 |author1=Kunkle, B. |author2=Fletcher, J. |author3=Mayo, D. | year = 2013 | title = Florida Cow-Calf Management, 2nd Edition - Feeding the Cow Herd | publisher = IFAS Extension, University of Florida | id = Publication #AN117 }} 10. ^1 {{cite journal |author1=Oltjen, R. R. |author2=Williams, E. E. |author3=Slyter, L. L. |author4=Richardson, G. V. | title = Urea versus biuret in a roughage diet for steers | journal = Journal of Animal Science | year = 1969 | volume = 29 | issue = 5 | pages = 816–822 | pmid = 5391979 | url = http://www.journalofanimalscience.org/content/29/5/816 }} 11. ^{{cite journal |author1=Fonnesbeck, P. V. |author2=Kearl, L. C. |author3=Harris, L. E. | title = Feed Grade Biuret as a Protein Replacement for Ruminants. A Review | journal = Journal of Animal Science | year = 1975 | volume = 40 | issue = 6 | pages = 1150–1184 | url = http://www.journalofanimalscience.org/content/40/6/1150 }} 2 : Ureas|Functional groups |
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