Insights into the myosin II inhibitory potency of A-ring-modified (S)-blebbistatin analogs.

Myosin II is an interesting target for therapeutic intervention, as it is involved in a large number of motility-based diseases. (S)-Blebbistatin is a known micromolar inhibitor of this protein. A new series of (S)-blebbistatin derivatives with a modified A-ring was synthesized and the myosin II inhibitory properties were evaluated in vitro. In this way, we gained insight into the influence of structural modifications in this part of the scaffold on myosin II inhibitory potency. Our results indicate there are few possibilities for potency enhancement via ring A modification of the blebbistatin scaffold.