We report the syntheses of five natural product maleimide and maleic anhydrides from the mushroom Antrodia camphorata. The ability of these compounds to affect proliferation in non-tumourigenic and tumourigenic liver progenitor cell lines was monitored by the Cellscreen system, a novel and nondestructive rapid-screening instrument. Additionally, a range of new aryl-functionalised differentiated derivatives were prepared through a Suzuki cross-coupling reaction to influence cell-growth effects. Several derivatives radically slowed the proliferation of liver progenitor cells; however, of particular interest were two maleic anhydride derivatives containing aryl tethers. These analogues demonstrated selectivity for limiting the proliferation of tumourigenic progenitor cells in comparison with their non-tumourigenic counterparts. Also highlighted is the application of the Cellscreen system in medicinal chemistry to rapidly measure the effect of compound libraries on cell proliferation.