Studies on vitamin D (Calciferol)and its analogues. 10. Side chain analogues of 25 hydroxyvitamin D3

Article abstract of DOI:10.1021/jm00211a002

A homologous series of side chain analogues of 25 hydroxyvitamin D₃ (25 hydroxycholecalciferol) in which the length of the side chain is modified while maintaining its characteristic tertiary hydroxyl moiety has been synthesized. The following five analogues have been prepared and characterized: pentanor 25 OH D₃ (2a), trinor 25 OH D₃ (2b), dinor 25 OH D₃ (2c), nor 25 OH D₃ (2d), and homo 25 OH D₃ (2e). Biological assays in vivo of intestinal calcium absorption and bone calcium mobilization in the chick of the five analogues revealed that the homo analogue 2e exhibited a significant biological response relative to the -D (-vitamin D₃) control. Compared to the natural vitamin D₃, 2e is as active in its ability to mobilize bone calcium and is about half as effective in stimulating intestinal calcium transport. The remaining analogues (2a d) exhibited no significant activity in either assay, although the nor analogue 2d was previously observed to exhibit antimetabolite activity.