Hypericum A-E: five unprecedented polycyclic polyprenylated acylphloroglucinols from Hypericum lagarocladum exhibiting PTP1B inhibitory activity.

Five new PPAPS compounds, Hypericum A-E (1-5), and twelve known compounds were isolated from Hypericum lagarocladum. The structures of these compounds were determined through a combination of methods such as mass spectrometry, ultraviolet spectroscopy, infrared spectroscopy, nuclear magnetic resonance spectroscopy and electron capture dissociation calculations. Compounds 5, 4, and 1 exhibited inhibitory activity against PTP1B with IC50 values of 6.50 ± 0.81 µM, 11.47 ± 1.06 µM, and 26.01 ± 1.42 µM, respectively, which indicated that these compounds are promising PTP1B inhibitor lead candidates.