A cell-permeable inhibitor of PTPs (IC50s = 0.09-1.7 µM) through oxidation of the catalytic cysteine residue; inhibits redox-sensitive CYP isoforms with IC50 values less than 10 µM; inhibits the protein methyltransferases SETD8, SETD2, G9a, SMYD2, CARM1, and PRMT3 with IC50 values from 0.7 to 3.2 µm.