. Author manuscript; available in PMC: 2009 Jun 1.

Published in final edited form as: J Steroid Biochem Mol Biol. 2008 Apr 22;110(3-5):269–277. doi: 10.1016/j.jsbmb.2007.11.007

Table 1.

Binding affinities of 1α,25-(OH)₂D₃-26,23-lactam analogues to competitively inhibit [³H]1α,25-(OH)₂D₃ binding to chick intestinal VDR

Compounds	50% Displacement (pg/tube)	Molar Ratio
1α,25-(OH)₂D₃	37.5	1
(23S,25S)-DLAM-1P	1,750	36.4
(23R,25R)-DLAM-1P	19,000	395.5
(23S,25R)-DLAM-1P	28,000	567.9
(23R,25S)-DLAM-1P	20,000	405.7
(23S,25S)-DLAM-2P	620	12.6
(23R,25R)-DLAM-2P	9,700	196.7
(23S,25R)-DLAM-2P	14,500	294.1
(23R,25S)-DLAM-2P	25,500	517.2

Molar ratio indicates the ratio of moles per liter of 1α,25-(OH)₂D₃ analogues over the moles per liter of 1α,25-(OH)₂D₃ required for 50% displacement of the [³H]1α,25-(OH)₂D₃ from the receptor. Each value of 50% displacement was calculated as the mean for duplicate determinations.