Effect of side-chain alteration on hormonal activity of nonsteroidal estrogen antagonists

Incorporation of novel side-chains in 3,4-diaryl chromans, an established nucleus present in the nonsteroidal estrogen antagonist centchroman, has been carried out. The effect of variation in the nature of the chain on relative binding affinity (RBA) to estrogen receptor, estrogenicity, and antiestrogenicity has been studied. Presence of hydrazide residue on cis- and trans-3,4-diaryl chromans led to relatively higher RBA and estrogenicity as compared with corresponding acids and esters.