vascular smoothmuscle cells, with potency similar or superior to that of the reference levcromakalim (LCRK). The selective KATP blocker glibenclamide antagonized the above vascular effects, confirming that KATPchannels are closely involved in the mechanism of action. The experimental results confirmed the 1,4-benzothiazine nucleus as an optimal scaffold for activators of vascular KATPchannels; moreover