Obacunone and obacunone glucoside inhibit human colon cancer (SW480) cells by the induction of apoptosis

► Isolated and Identified obacunone and obacunone glucoside from Marsh White grapefruits for the first time. ► Inhibition of human colon cancer cell (SW480) proliferation was reported for the first time. ► Possible mode of apoptosis induction by limonoids in human colon cancer cells. ► Combining limonoids with camptothecin demonstrated additive apoptosis was observed in colon cancer cells.