Structure–activity relationship translation offers
an expeditious
means for discovery of new active series. This approach was applied
to discover tetrahydroisoquinoline (THIQ)-based steroidomimetic microtubule
disruptors. The two A-ring elements of a three-point steroidal pharmacophore
were incorporated into a THIQ-based A,B-ring mimic to which an H-bond
acceptor was attached as the third motif. Optimization of the representative 6c through conformational biasing delivered
a 10-fold gain in activity and a new series of microtubule disruptors
(e.g., 9c) with antiproliferative activity in the nanomolar
range. The THIQ derivatives match, or surpass, the activities of the
steroidal series and exhibit improved physicochemical properties.