Provided is a prodrug of 2-nitro-1-imidazolepropionic acid and a therapeutically active organic compound having an amino group, cyclic amino group or hydroxyl group in the molecule, particularly a prodrug in which the therapeutic organic compound is selected from antitumor agents Is done. Such prodrugs are cleaved specifically under hypoxia in vivo and exhibit their original therapeutic activity.２－ニトロ－１－イミダゾールプロピオン酸と分子中にアミノ基、環状アミノ基またはヒドロキシル基を持つ治療的活性有機化合物のプロドラッグ、特に、治療的有機化合物が抗腫瘍剤から選ばれるプロドラッグが提供される。かかるプロドラッグは、生体内の低酸素下で特異的に開裂し、本来の治療的活性を示す。
