Regeneration of amino acids from thiazolinones formed in the Edman degradation.

Conditions for regeneration of amino acids from their thiazolinone derivatives formed in the cleavage step of the Edman degradation procedure have been investigated. Highest yields of most amino acids including methionine were obtained simply by hydrolysis in 5.7n HCl containing 0.1% SnCl₂ for 4 hr at 150°C. Results from other methods of hydrolysis are provided for comparison. The hydrolytic yield of amino acids from the anilinothiazolinones determined in this study may be used to estimate the cleavage yield at each step of the Edman degradation.