SURVEYING THE EFFECTS OF ELDECALCITOL AND RELATED ANALOGS FROM A BIOLOGICAL PERSPECTIVE

In the previous review paper, explorative and developmental researches of eldecalcitol (1 alpha,25-dihydroxy-2 beta-(3-hydroxypropoxy)vitamin D-3), an analog of active vitamin D-3, calcitriol (1 alpha,25-dihydroxyvitamin D-3), were introduced. Eldecalcitol possesses potent effects on bone disease such as osteoporosis. The completion of a phase III clinical trial of eldecalcitol for bone fracture prevention in comparison with alfacalcidol (1 alpha-hydroxyvitamin D-3), prodrug of calcitriol, produced excellent results. Although clinically, eldecalcitol showed greater potency than calcitriol/alfacalcidol, the detailed physiological properties and mechanism of action of the enhanced activity of eldecalcitol toward bone remains to be clarified. To explore structure-activity relationships, related analogs of eldecalcitol have been synthesized with inherent biological background of each targeted analogs. These include epimeric analogs at 1, 2, 3, and 20 positions, nor analog at 19 position and deoxy analogs at 1 and 25 positions. This review discusses eldecalcitol and related analogs in a biological perspective. The synthetic features of analogs are also outlined.