QSAR Analysis of Indazole Estrogens as Selective β-Estrogen Receptor Ligands: Rationalization of Physicochemical Properties

Quantification of structure activity relationships was performed on a series of indazole estrogen analogs, for their relative β estrogenic receptor agonist activity, in order to understand the essential structural requirements for selectivity of indazole estrogen analogs for β-estrogenic receptor over α-estrogenic receptor. The de novo and Hansch approach suggested that the 3rd position of indazole nucleus (R1) is decisive for the selectivity of molecules towards β- estrogenic receptor over β-estrogenic receptor. The study also depicted that the substitution of polar group at R1 position might prove helpful in the β-estrogenic receptor selectivity (ERβ/α).