What is the reaction in Xanthoproteic test?
What is the reaction in Xanthoproteic test?
The Xanthoproteic test uses a nitration reaction to determine the presence of proteins in a solution. When the sample is treated with a hot, concentrated nitric acid it reacts with aromatic amino acids such as phenylalanine, tyrosine and tryptophan and forms a yellow colored product known as Xantho protein.
What is the positive result for the Xanthoprotein test?
Positive result: The appearance of a dark yellow or orange-colored solution represents a positive test. This indicates the presence of aromatic groups in the proteins and amino acids. Negative result: The absence of a dark yellow or orange-colored solution represents a negative test.
Does gelatin give a positive Xanthoproteic test result?
2- Mix well and put in a boiling water bath for few minutes; a black deposit is formed with albumin and gelatin gives negative result. 2- Xanthoproteic acid test: This test is used to differentiate between aromatic amino acids which give positive results and other amino acids.
Do most proteins give a positive Xanthoproteic test?
Xanthoproteic Test When this yellow solution is treated with a strong base (such as NaOH), it turns orange. Since most proteins contain one or both of these amino acids, most proteins will show a positive reaction in this test.
What is the formula of xanthoproteic acid?
Xanthoproteic acid is a yellow colour compound with the formula C34H24N4O122HO.
Will all amino acids give a positive Xanthoproteic test?
A free amino group comprises nearly all amino acids (except proline and hydroxyproline). Some proteins have a positive ninhydrin test as well. The amino acids that have the benzene ring activated can easily undergo nitration.
What is the use of Xanthoprotein test in diagnosis of disease?
Xanthoproteic test is used to detect amino acids containing an aromatic nucleus (tyrosine, tryptophan and phenylalanine) in a protein solution which gives yellow color nitro derivatives on heating with conc. HNO3. The aromatic benzene ring undergoes nitration to give yellow colored product.
What makes the Xanthoproteic test turns yellow orange when it is exposed in water bath?
Xanthoproteic test is specific for protein containing aromatic amino acids. The benzene ring in the amino acids is nitrated by heating with nitric acid and forms yellow nitro-compounds which turns to orange colour with alkali.
What is the color of gelatin in Xanthoproteic test?
Bluish violet colour
Observation
| SI No. | Sample | Observation |
|---|---|---|
| 1. | Egg albumin dispersion | Bluish violet colour is formed. |
| 2. | Gelatin dispersion | Bluish violet colour is formed. |
Do all amino acids give a positive Xanthoproteic test explain?
Why is xanthoproteic important?
Xanthoproteic test is used to detect amino acids containing an aromatic nucleus (tyrosine, tryptophan and phenylalanine) in a protein solution which gives yellow color nitro derivatives on heating with conc. HNO3.
How do you make xanthoproteic reagent?
Procedures
- Take 1ml test solution in dry test tube.
- Similarly, take 1ml distilled water in another test tube as control.
- Add 1ml of conc. HNO3 in all test tubes and mix well.
- Cool the solution under tap water.
- Now add 2ml of 40 % NaOH to all test tubes.
- Look for the color development.