kinesine spindleprotein (KSP) inhibitors based on the pharmacophore we have mapped and the crystal structure of monastrol bound to the target protein. The KSP inhibitory activities of all the designed compounds were tested using cloned Human KSP protein. All thirteen compounds were more potent than the control, monastrol, in Human KSP protein adenosine triphosphatase (ATPase) assays. Three compounds (1b