to facilitate complete quantitation of the resulting phenylthiohydantoin ( pth ) -amino acids , the pth derivatives of the following side chain-protected amino acid residues have been synthesized : arg ( tos ) , asp ( obzl ) , cys ( 3,4- ( ch3 ) 2-bzl ) , glu ( obzl ) , lys ( 2-clz ) , ser ( bzl ) , thr ( bzl ) , tyr ( 2-brz ) , and tyr ( 2,6-cl2bzl ) .
C0002520
amino acids
C0061472
glu