Synthesis and evaluation of copper complexes of Schiff-base condensates from 5-substituted-2-hydroxybenzaldehyde and 2-substituted-benzenamine as selective inhibitors of protein tyrosine phosphatases

Five copper complexes of Schiff-base condensates from 5-substituted-2-hydroxy-benzaldehyde and 2-substituted-benzenamine were synthesized and characterized. The copper complexes noncompetitively inhibit PTP1B, TCPTP, PTP-MEG2 and SHP-1, but do not inhibit SHP-2. Complex 5 exhibits very strong inhibition and better selectivity against PTP1B (IC50 = 0.059 μM).