Abstract: An anthraquinone compound of formula I (such as the compounds of formulae II to X) and processes for making the same are provided. Pharmaceutical compositions for use in the treatment of cancer, optionally in combination with an agent capable of reducing the level of oxygenation of a tumour, are also provided. Additionally, an option for combination with chemotherapeutic and radiotherapeutic modalities to enhance overall tumour cell kill is provided. Methods for the detection of cellular hypoxia, both in vivo and in vitro, are additionally provided.