BVT 948 is a noncompetitive, cell-permeable inhibitor of protein tyrosine phosphatases (PTP; IC50s = 0.09-1.7 μM). displays irreversible inhibition through catalysis of the hydrogen peroxide-dependent oxidation of PTP. Enhances insulin signaling in vitro and insulin tolerance in ob/ob mice in vivo. MW: 241.25. Purity ≥98%