The present invention relates to novel antineoplastic agents and cancer diagnostic agents that specifically target neo-plastic cells via the GLUT transportation system. More specifically, the invention relates to conjugates of 2-deoxyglucose, wherein a linker, which includes a covalent bond, is attached to 2-deoxyglucose at the 2 position, and the linker is attached to a therapeutic or diagnostic agent. The invention also relates to methods of treating tumor disease and methods of making the novel compounds of the present invention. The agents of the present invention are superior to previous agents as they are targeted via GLUT transporters.