Ohioensins F and G: Protein tyrosine phosphatase 1B inhibitory benzonaphthoxanthenones from the Antarctic moss Polytrichastrum alpinum

Ohioensins F and G (1 and 2), two new benzonaphthoxanthenones, have been isolated from the MeOH extract of Antarctic moss Polytrichastrum alpinum by various chromatographic methods. The structures of these compounds were determined mainly by analysis of NMR spectroscopic data. The known compounds ohioensins A and C (3 and 4) were also obtained. Compounds 1–4 showed potent inhibitory activity against therapeutically targeted protein tyrosine phosphatase 1B (PTP1B). Kinetic analysis of PTP1B inhibition by ohioensin F (1) suggested that benzonaphthoxanthenones inhibited PTP1B activity in a non-competitive manner.

Graphical abstractOhioensins F and G were isolated from Polytruchastrum alpinum and evaluated for their PTP1B inhibitory activities.Figure optionsDownload full-size imageDownload as PowerPoint slide