Antitumor activity of novel deoxoartemisinin monomers, dimers, and trimer

The first primary amines 9 and bromoalkyl analogues 7 of deoxoartemisinin with nonacetal functionality at C-12 are prepared as versatile intermediates for the synthesis of various derivatives. Eight C-12 nonacetal type dimers and one trimer of deoxoartemisinin were prepared using novel chemistry. Dimers, particularly 12a, 18a,b, and trimer 17, were especially potent and selective at inhibiting the growth of certain human cancer cell lines and were comparable to that of clinically used anticancer drugs. The linker with one amide- or one sulfur-centered two ethylene groups of the dimers is essential for high anticancer activity. Trimer 17 shows very potent activity against most of the human cancer cell lines tested.