Purity ~98% (HPLC). A cell-permeable dihydropyrazinyl-thioacetamide that acts as an ATP-competitive MARK-selective inhibitor (IC50=3.6uM; [ATP]=100uM). Shown to effectively block primary rat cortical neuron axon growth (5.7um/hr vs 32.5um/hr with or without 20uM inhibitor) and prevent MARK2 overexpression-induced Tau Ser262 phosphorylation and cytotoxicity in CHO cells (10uM). Formula: C21H21N3O3S Molecular Weight: 395.5 Solubility: DMSO (100mg/ml clear, yellow solution)