2-amino-5-[(4-hydroxy-4-oxobutyl)amino]-5-oxopentanoic acid 2-amino-5-[(4-hydroxy-4-oxo-butyl)amino]-5-oxo-pentanoic acid 2-amino-5-[(4-hydroxy-4-keto-butyl)amino]-5-keto-valeric acid AIDS-130685 AIDS130685 NSC609423 N~5~-(3-Carboxypropyl)glutamine