Monastrol is primarily used in biological and biochemical research as a selective inhibitor of the mitotic kinesin Eg5. This kinesin plays a crucial role in the formation of the bipolar spindle during cell division, making Monastrol a valuable tool for studying cell cycle mechanisms and mitosis. By inhibiting Eg5, Monastrol induces the formation of monoastral spindles, leading to cell cycle arrest in the mitotic phase. This property is exploited in cancer research to investigate potential therapeutic strategies that target mitosis, particularly in cancers characterized by uncontrolled cell proliferation. Additionally, Monastrol serves as a model compound in the development of other Eg5 inhibitors, aiding in the exploration of novel anti-mitotic drugs. Its application extends to studies of cellular processes, such as chromosome segregation and spindle dynamics, providing insights into fundamental biological functions and potential drug targets.