Discovery of novel bromophenol 3,4-dibromo-5-(2-bromo-3,4-dihydroxy-6-(isobutoxymethyl)benzyl)benzene-1,2-diol as protein tyrosine phosphatase 1B inhibitor and its anti-diabetic properties in C57BL/KsJ-db/db mice.

In an effort to develop novel small molecule PTP1B inhibitors, a series of bromophenol derivatives were designed, synthesized and evaluated in vitro and in vivo. All of the synthesized compounds displayed weak to potent PTP1B inhibitory activities (5.62-96.25%) at 20 μg/mL. Among these compounds, 3,4-dibromo-5-(2-bromo-3,4-dihydroxy-6-(isobutoxymethyl)benzyl)benzene-1,2-diol (9) exhibited enhanced PTP1B inhibitory activity (IC50 = 1.50 μM) than the lead compound BDDPM (IC50 = 2.42 μM) and high selectivity against other PTPs (TCPTP, LAR, SHP-1 and SHP-2). Results of anti-diabetic assay using C57BL/KsJ-db/db mouse model demonstrated that compound 9 was effective at lowering blood glucose, total cholesterol and HbA1c (P < 0.01).