PTP1B inhibitors from the seeds of Iris sanguinea and their insulin mimetic activities via AMPK and ACC phosphorylation

To find PTP1B inhibitors from natural products, two new compounds (1 and 2), along with nine known compounds (3–11), were isolated from a methanol-soluble extract of Iris sanguinea seeds. The structures of compounds 1 and 2 were determined based on extensive spectroscopic data analysis including UV, IR, NMR, and MS. The IC₅₀ value of compound 5 on protein tyrosine phosphatase 1B (PTP1B) inhibitory activity is 7.30 ± 0.88 µM with a little activity compared to the IC₅₀ values of the tested positive compound. Compound 5 significantly enhanced glucose uptake and activation of pACC, pAMPK and partially Erk1/2 signaling. These results suggest that compound 5 from Iris sanguinea seeds are utilized as both PTP1B inhibitors and regulators of glucose uptake. These beneficial effects could be applied to treat metabolic diseases such as diabetes and obesity.