(2S,2'S)-5,5'-(((2R,2'R)-Disulfanediylbis(1-((carboxymethyl)amino)-1-oxopropane-3,2-diyl))bis(azanediyl))bis(2-amino-5-oxopentanoic acid)
(S)-4-Amino-5-(((S)-1-carboxy-2-(1H-indol-3-yl)ethyl)amino)-5-oxopentanoic acid
(S)-5-Amino-2-((R)-2-chloropropanamido)-5-oxopentanoic acid
(S)-4-Amino-5-(((S)-1-carboxyethyl)amino)-5-oxopentanoic acid
(S)-2-Amino-5-(((S)-1-((carboxymethyl)amino)-3-methyl-1-oxobutan-2-yl)amino)-5-oxopentanoic acid
(S)-5-Amino-2-(2-aminoacetamido)-5-oxopentanoic acid
5-((2-(1H-Imidazol-5-yl)ethyl)amino)-5-oxopentanoic acid
(S)-5-Amino-2-((S)-2-aminopropanamido)-5-oxopentanoic acid
(S)-2-Amino-5-(((R)-1-((carboxymethyl)amino)-3-mercapto-1-oxopropan-2-yl)amino)-5-oxopentanoic acid
(S)-2-Amino-5-(isopropylamino)-5-oxopentanoic acid
5,5'-(Decane-1,10-diylbis(oxy))bis(5-oxopentanoic acid)
5-Amino-4-oxopentanoic acid phosphate
(S)-2-Amino-5-(((R)-1-((carboxymethyl)amino)-3-(nitrosothio)-1-oxopropan-2-yl)amino)-5-oxopentanoic acid
(S)-4-((S)-2-Aminopropanamido)-5-(((S)-3-carboxy-1-((carboxymethyl)amino)-1-oxopropan-2-yl)amino)-5-oxopentanoic acid
4-(3,4-Dichlorobenzamido)-5-((3-methoxypropyl)(pentyl)amino)-5-oxopentanoic acid
(S)-5-tert-Butoxy-4-(3-((S)-1,5-di-tert-butoxy-1,5-dioxopentan-2-yl)ureido)-5-oxopentanoic acid
3-Methyl-2-oxopentanoic acid
(S)-5-(2,6-Difluorophenoxy)-3-((S)-3-methyl-2-(quinoline-2-carboxamido)butanamido)-4-oxopentanoic acid
5-(4-Fluorophenyl)-5-oxopentanoic acid
