Patent ID: 7129215

Claim:
A compound of the formula or its C 1-10 alkyl, phenyl-C 1-3 alkyl, or (C 5-6 heteroaryl)-C 1-3 alkyl mono- or di-ester, or a salt of the compound or its mono- or di-ester where: n is 0 or 1; W is L-γ-glutamyl or L-γ-glutamylglycyl; X is optionally substituted C 5-6 cycloalkyl, optionally substituted C 5-6 heterocycloalkyl, optionally substituted phenyl, or optionally substituted C 5-6 heteroaryl; Y is ═O, ═N—OH, or ═N—O(optionally substituted C 1-3 alkyl); and Z is optionally substituted phenyl or optionally substituted C 5-6 heteroaryl.