- Synthesis and biological evaluations of A-ring isomers of 26,26,26,27,27,27-hexafluoro-1,25-dihydroxyvitamin D3
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The activated vitamin D3 derivative 26,27-F6-1α,25(OH)2D3 (2a), its three A-ring diastereomers (2b, 2c, 2d), and 5,6-trans isomer (2e) were prepared. Two analogues (2b, 2c) of these isomers were synthesized by a palladium catalyzed coupling reaction using vinyl bromide 5 and enynes (6a, 6b), which were derived from readily commercially available 2S-(+)-glycidyl p-toluenesulfonate 7, as a common starting material. Competitive vitamin D receptor (VDR) binding affinities of these diastereomers of 2a were evaluated. Interestingly, the stereochemical effects at C-1,3 of 2a were considerably more moderate than those of 1α,25(OH)2D3 (1). In particular, isomerization at the 5,6-double bond of 2a only slightly reduced VDR affinity, whereas 5,6-trans-1α,25(OH)2D3 had a significantly lower binding affinity than 1. Copyright (C) 2000 Elsevier Science Ltd.
- Ikeda, Masahiko,Takahashi, Kazuhiko,Dan, Akihito,Koyama, Kohji,Kubota, Katsumi,Tanaka, Tomoyuki,Hayashi, Masaji
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p. 2157 - 2166
(2007/10/03)
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- Kinetics of thermal [1,7A]-sigmatropic shift of hexafluoro vitamin D3 and vitamin D3 derivatives. Evaluation of conformations of the A ring affected by 1-OH and 3-OH groups
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The quantitative evaluation of the [1,7a]-sigmatropic rearrangement of vitamin D3 and its analogs affected by the conformations of the A ring using the 1H-NMR method was described. Although the side chain of the D ring had no effect on the hydrogen migration, the rearrangement was influenced by the hydroxy groups of the A ring.
- Igarashi, Jun-Etsu,Ikeda, Masahiko,Sunagawa, Makoto
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p. 1431 - 1436
(2007/10/03)
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- Immunosuppressive agents
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The invention relates to pharmaceutical compositions comprising at least one Vitamin D derivative and a method of using the pharmaceutical compositions in suppressing immune responses.
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