Abstact

Vitamin D receptor (VDR) is an attractive target of drug discovery for multiple diseases. In this study, we systematically designed and synthesized a series of diphenylsilane derivatives with diverse hydrophobic substituents and investigated their structure-activity relationship (SAR) as VDR agonists. The SAR study revealed that the activity is dependent on the type of substituent and the position of substitution, and the diethyl-di-m-tolylsilane scaffold was identified as the most suitable hydrophobic core structure of this type of VDR ligands. Interestingly, the small structural difference between n-propyl and allyl substituents resulted in a large difference in the activity. Comparison of the co-crystal structures of 14 diphenylsilane compounds, including less potent compounds, bound to the rat VDR ligand-binding domain suggested that the differences in activity are due to a combination of factors, including differences in hydrophilic and hydrophobic interactions, and ligand conformations.