Problem Set 22B. Anthranilic Acid and 3-Hydroxyanthranilic Acid

 

Given:

a. In bacteria, the second stage of tryptophan catabolism starts with anthranilic acid


b. Oxygenases  tend to operate adjacent to a hydroxyl or amino group.

c. Ring cleavage does not occur adjacent to an amino group.

d. A carboxyl group can add to a suitably placed double bond to form an internal ester called a lactone.

e. Picolinic acid and quinolinic acid are found in human urine.


1. Write two mechanisms for oxidative deamination of anthranilic acid.

2. Write a mechanism for opening the catechol ring.

3. Write reactions for catabolism of muconic acid.

4. Muconic acid can cyclize. Show how, and name the favored product.

5. Write two possible pathways for the first two steps in the catabolism of muconolactone (2-keto-2,5-dihydrofuran-5-acetic acid). How can you decide between these two possibilities?

6. Write two possible catabolic reactions of β-ketoadipic acid?

7.  Show how CoA can be transferred from succinyl-CoA to β-ketoadipate:

8. Construct a mini cycle for transfer of CoA from succinyl-CoA to β-ketoadipic acid. Include the enzymes.

9. Construct a map for catabolism of tryptophan in bacteria (ortho oxidation).

10. We are given that quinolinic acid is found in human urine. What conclusions can you draw?

11. Construct a pathway for catabolism  of 2-amino-3-carboxymuconic acid semialdehyde.

12. Construct a map for catabolism of tryptophan in Home sapiens:

 

 

 

 

 

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