Synthesis and radiolabelling of Re(CO) 3 ‐ β ‐elemene derivatives as potential therapeutic radiopharmaceuticals

β ‐Elemene, (1 S , 2 S , 4 R )‐(−)‐(1‐methy‐1‐vinyl‐2,4‐diisopropenyl cyclohexane) is an anticancer agent from the Traditional Chinese Herb Medicinal . Three novel Re(CO) 3 ‐ β ‐elemene derivatives including their radioactive conjugates containing N , N , N tridentate ligands and tricarbonyl rhenium (complex 12, 13, 14) were synthesized. Their structures were characterized by infrared (IR), 1 H‐NMR and HRMS. Good radioactive yield (above 90%) and radioactive chemical purity with Re‐188 (above 95%) were obtained for all of the three derivatives (complex 15, 16, 17). The antiproliferative activity of non‐radioactive β ‐elemene‐Re(CO) 3 derivatives on Lewis lung cancer cells and HeLa cell lines were evaluated by WST‐1 methods. The result shows substantial decrease in IC 50 values compared with the parent compound β ‐elemene. The synthesis and radiosynthesis of β ‐elemene tricarbonyl rhenium conjugates provide the possibility to find a new kind of potential radiopharmaceuticals on β ‐elemene. Copyright © 2009 John Wiley & Sons, Ltd.