New 1 alpha,25-dihydroxy vitamin D3 analogues with side chains attached to C-18: synthesis and biological activity.

A new class of analogues of 1 alpha,25-dihydroxy vitamin D3 has been synthesised, in which the side chain (C-23 to C-27) has been removed and where new hydroxylated side chains have been attached to the C-18 methyl group. These analogues show antiproliferative activity in U937 and HaCaT cells comparable to that of 1 alpha,25-dihydroxy vitamin D3. Lack of calcemic activity makes these analogues potentially useful in the treatment of proliferative diseases.