Protein tyrosine phosphatase (PTP) 1B is a potential therapeutic target for type 2 diabetes. Due to the pos. charged and highly conserved nature of its catalytic site, PTP1B is an intractable target for drug discovery. Extensive efforts have been made by us in the recent years to discover novel PTP1B inhibitors targeting both catalytic and allosteric sites of PTP1B. Figure 1. Lead discovery targeting both catalytic and allosteric sites of PTP1B. As illustrated in Figure 1, the known PTP1B inhibitors 1 and 2, which act on the catalytic and allosteric sites of PTP1B resp., were taken as chem. templates. Composite pharmacophore models were extracted from the binding poses of the templates and pharmacophore-oriented scaffold hopping was then performed. Derived from both compounds, novel PTP1B inhibitors with distinct scaffolds and significant in vivo insulin-sensitizing effects were identified. To further extend the structural diversity, 3D-QSAR pharmacophore models were established for known catalytic inhibitors of PTP1B. Virtual screening of natural product databases with this model as well as mol. similarity and docking scores has led to the recognition of a series of unique coumarins as potent PTP1B inhibitors. Mol. dynamics simulations were also carried out to unveil the allosteric mechanism of our newly identified non-competitive inhibitors, so as to facilitate future mol. design targeting the allosteric site. Acknowledgements: This investigation was supported by the National Natural Science Foundation of China (Number 20972192) and Natural Science Foundation of Beijing (Number 7102117).