Is anthranil acid subject to deamination in animals?

All metabolic pathways of natural amino acids lead to the Krebs cycle. However, only nitrogen-free acyclic compounds can enter the Krebs cycle. In animals, however, the products of deamination and decyclization of amino acids are not only oxidized to end products in the Krebs cycle, but are also converted to glucose and ketone bodies. Consequently, every natural amino acid has a glucogenic or ketogenic effect, and some amino acids have a glucoketogenic or mixed effect, because they form both a glucogenic and a ketogenic product in the process of degradation. Tryptophan is such an amino acid. One of the degradation products of tryptophan is anthranilic acid. While the conversion of another degradation product of tryptophan, 3-hydroxyanthranilic acid, has long been known and is the cause of the ketogenic effect of tryptophan, the conversion of anthranilic acid has long remained unclear. This has led to various judgments that have not allowed true conclusions about the action of anthranilic acid (glucogenic or ketogenic) and, consequently, the final judgments about the action of tryptophan in animals. The article analyzes the conversion of anthranilic acid in animals, which allows us to conclude about the metabolic pathway of tryptophan through it. The article shows the impossibility of direct deamination of anthranilic acid in animals with the glucogenic effect of anthranilic acid resulting from direct deamination, and also shows the ketogenic effect of anthranilic acid due to its oxidation to 3-hydroxyanthranilic acid. Since both acids are intermediates in the degradation of the protein amino acid tryptophan, this fact should be taken into account in the diets of normal and pathological animals.

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