Analogs of Calcitriol

Recent Developments of 19‐Nor‐1,25‐dihydroxyvitamin D3 Analogues

“…Reorientation of the hydrogen atom on C14 into the cis configuration (14‐epimerization of 1 ) decreased affinity for VDR and DBP, but also markedly diminished calcemic effect 54. However, 14‐epimerization of 2 gave 14‐epi‐19‐nor‐1,25(OH) 2 D 3 , which showed activity roughly similar to that of 1,25(OH) 2 D 3 , depending on the cell type investigated.…”

WY 1048, a 17-methyl 19-nor D-ring analog of vitamin D3, in combination with risedronate restores bone mass in a mouse model of postmenopausal osteoporosis

“…Despite this lower VDR affinity, 10-fold lower concentrations of WY 1048, compared with 1,25(OH)2D3, were sufficient to reach half-maximal inhibition of MCF-7 breast cancer cell proliferation and 3-fold lower concentrations were enough to obtain half-maximal differentiation of HL60 promyelocytic cells [14,15]. Evaluation of its calcemic effects revealed that a short-term treatment with 0.2 µg/kg/d WY 1048 induced a small gain in femoral calcium content without affecting serum and urinary calcium concentrations.…”

Update on pharmacologically‐relevant vitamin D analogues

“…Thousands of molecules have been prepared and tested but only a few of these have been successfully translated into marketed drug forms that can be used to treat bone disease or in other areas of clinical medicine. These synthetic vitamin D analogues have been reviewed extensively in recent years and this chapter will not attempt to duplicate those reviews. Furthermore, this review will not spend much time exploring the precise biochemical mechanism by which the active form of vitamin D 3 , 1,25‐dihydroxyvitamin D 3 [1,25‐(OH) 2 D 3 ] is able to modulate gene expression of target genes involved in the physiological effects of vitamin D on calcium/phosphate homeostasis or its effects on cell proliferation and differentiation covered in recent summaries of this subject .…”