A potent RSK2 inhibitor (IC50 = 1.1 nM) that also demonstrates off-target binding at multiple adrenergic receptor subtypes that are important for vascular tone and cardiac function (IC50s = 0.052-1.820 μM for adrenergic α1A, α1B, α1D, α2A, β2, and imidazoline I2 receptors); also inhibits LRRK2 and PRKD1 (IC50s = 16 and 35 nM, respectively)