New dimeric phloroglucinol derivatives from Agrimonia pilosa and their hepatoprotective activities

Abstract

Five new dimeric phloroglucinol derivatives, agrimones A - E (1-5), were isolated from the whole plant of Agrimonia pilosa. Their structures including absolute configurations were determined by a series of spectroscopic data (UV, IR, HR-ESI-MS, 1D and 2D NMR), complemented with the comparison of the experimental and calculated ECD spectra, and gauge-independent atomic orbital (GIAO) NMR calculations. Notably, compounds 1 and 2 represent a highly oxidized 6/6/6 tricyclic ring skeleton based on the cis-fused paraquinone and chroman. Compounds 1a, 4, and 5 exhibited moderate hepatoprotective activities against APAP-induced HepG2 cell injury at 10 μM.

Keywords: Agrimonia pilosa; Dimeric phloroglucinols; Hepatoprotective activity; Rosaceae.