Structural analysis and biological activities of C25-amino and C25-nitro vitamin D analogs.

Intense synthetic efforts have been directed towards the development of noncalcemic analogs of 1,25-dihydroxyvitamin D. We describe here the structural analysis and biological evaluation of two derivatives of 1,25-dihydroxyvitamin D with modifications limited to the replacement of the 25-hydroxyl group by a 25-amino or 25-nitro groups. Both compounds are agonists of the vitamin D receptor. They mediate biological effects similar to 1,25-dihydroxyvitamin D, the 25-amino derivative being the most potent one while being less calcemic than 1,25-dihydroxyvitamin D. The in vivo properties of the compounds make them of potential therapeutic value.