3DMet B00969 Density 1.467 g/cm³ | Formula C2H5N3O2 Appearance White crystals | |
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Biuret s test qualitative test in proteins
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.
Contents
- Biuret s test qualitative test in proteins
- Biuret test for protein
- Preparation
- Applications
- Biuret test
- Related compounds
- References
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.
Biuret test for protein
Preparation
The parent compound can be prepared by heating urea above the melting point at which temperature ammonia is expelled:
2 CO(NH2)2 → H2N-CO-NH-CO-NH2 + NH3
Under related conditions, pyrolysis of urea affords triuret ((H2N-CO-NH)2CO). 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.
Applications
Biuret is also used as a non-protein nitrogen source in ruminant feed, where it is converted into protein by gut microorganisms. It is less favored than urea, due to its higher cost and lower digestibility but this characteristic also slows down its digestion and so decreases the risk of ammonia toxicity.
Biuret test
The 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
