Since many estrogen derivatives exhibit anti-hormone or enzyme inhibition potential,
a large number of steroidal derivatives have been synthesised from appropriate precursors,
in order to obtain potential therapeutics for the treatment of hormone-dependent cancers.
In molecular docking studies, based on X-ray crystallographic analysis, selected D-homo
and D-seco estratriene derivatives were predicted to bind strongly to estrogen receptor
alpha (ERalpha), aromatase and 17,20 lyase, suggesting they could be good starting
compounds for antihormonal studies. Test results in vivo suggest that these compounds
do not possess estrogenic activity, while some of them showed weak anti-estrogenic
properties. In vitro anti-aromatase and anti-lyase assays showed partial inhibition
of these two enzymes, while some compounds activated aromatase. Aromatase activators
are capable of promoting estrogen synthesis for treatment of pathological conditions
caused by estrogen depletion, e.g. osteopenia or osteoporosis.