Patent ID: 6924271

Claim:
A compound represented by Formula I: wherein R 1 is independently H, —C(O)R 3 , or a racemic, L-, or D-amino acid group —C(O)CHNH 2 R 4 , wherein R 3 is alkyl and R 4 is H, or alkyl; wherein alkyl is optionally substituted by one or more groups selected from halogen, —C 1 -C 6 , —OH, —NO 2 , —CN, —CO 2 H, —O—C 1 -C 6 , -aryl, -aryl-C 1 -C 6 , —CO 2 CH 3 , —CONH 2 , —OCH 2 CONH 2 , —NH 2 , —SO 2 NH 2 , haloalkyl, and —O-haloalkyl; R 2 is OR 5 or N(R 6 ) 2 , wherein R 5 is H and R 6 is independently H, alkyl, cycloalkyl, or together with nitrogen forms a heterocycloalkyl ring, wherein the alkyl, cycloalkyl, and heterocycloalkyl are ontionally substituted by one or more groups selected from halogen, —C 1 -C 6 , —OH, —NO 2 , —CN, —CO 2 H, —O—C 1 -C 6 , -aryl, -aryl-C 1 -C ( 6 , —CO 2 CH 3 , —CONH 2 , —OCH 2 CONH 2 , —NH 2 , —SO 2 NH 2 , haloalkyl, and —O-haloalkyl; and wherein at least one of the R 1 groups is a racemic, L-, or D-amino acid group—C(O)CHNH 2 R 4 ; or a pharmaceutically acceptable salt.