Glutathione N-hydroxycarbamoyl thioesters and method of inhibiting neoplastic growth

A compound of the formula (I) with R being hydrogen, alkyl, cycloalkyl or aryl, which may be substituted with halogen or alkyl, and R' and Ra being hydroxyl, or -O-alkyl, pharmaceutically acceptable salts thereof; or mixtures thereof. An anti-neoplastic composition comprises the compound described above and a pharmaceutically acceptable carrier. In vitro and in vivo methods of preventing or inhibiting the growth and proliferation of neoplastic cells and/or tumors comprise contacting the cells with or administering to a subject an anti-growth and proliferation effective amount of the compound described above. A compound of the formula (I) with R being hydrogen, alkyl, cycloalkyl or aryl, which may be substituted with halogen or alkyl, and R' and Ra being hydroxyl, or -O-alkyl, pharmaceutically acceptable salts thereof; or mixtures thereof. An anti-neoplastic composition comprises the compound described above and a pharmaceutically acceptable carrier. In vitro and in vivo methods of preventing or inhibiting the growth and proliferation of neoplastic cells and/or tumors comprise contacting the cells with or administering to a subject an anti-growth and proliferation effective amount of the compound described above.