Phenylalanine metabolism in cockroaches, Periplaneta americana: Tyrosine and benzoyl-β-glucoside biosynthesis

Abstract

• 1.

  1. Teneral adult male cockroaches, Periplaneta americana, produced more ¹⁴CO₂ from phenylalanine-1-¹⁴C than did the mature, fully tanned males. This would indicate utilization of phenylalanine-derived tyrosine for N-acetyl-dopamine biosynthesis during the time of cuticular sclerotization.

• 2.

  2. Tyrosine biosynthesis from phenylalanine occurred from ecdysis throughout adult life. Less tyrosine accumulated during the teneral period due to increased utilization for cuticular tanning.

• 3.

  3. A second major metabolite of phenylalanine was benzoic acid, most of which was conjugated as benzoyl-β-glucoside. The glucoside was not produced during the teneral period, suggesting changes in phenylalanine metabolism during ecdysis similar to those of tyrosine.

• 4.

  4. Phenylpyruvic acid-U-¹⁴C was rapidly metabolized to phenylalanine and tyrosine, indicating a transaminase in cockroach tissues with the equilibrium of transamination in the direction of the amino acid.