ERβ Ligands. Part 2: Synthesis and structure–activity relationships of a series of 4-hydroxy-biphenyl-carbaldehyde oxime derivatives Original Research Article

A series of biphenyl carbaldehyde oximes (6) was prepared and shown to have significant selectivity for the estrogen receptor-β (ERβ). The exploitation of the oxime moiety as a hydrogen bond donating group, which mimicked the C-ring of genistein makes these compounds unique. Molecular modeling studies showed the oxime moiety hydrogen bonding to the histidine residue, which was supported by the structure–activity relationships. The most potent compounds in this study had IC50 values in a radioligand binding assay of between 8–35 nM. Among the most selective compounds were 6i and 6s (49- and 31-fold ERβ selective, respectively).