Abieshanesides A and B, two unique ent-18,19-dinoricetexane diterpenoid glycosides from Abies beshanzuensis M.H. Wu.

Two unprecedented ent-18,19-dinoricetexane diterpenoid glycosides, named abieshanesides A (1) and B (2), together with seven known compounds, have been isolated from the dead trunks and branches of Abies beshanzuensis M.H. Wu. To our knowledge, abieshanesides A and B represent the first ent-18,19-dinoricetexane diterpenoid glycosides found in natural sources. Their structures and absolute configurations were elucidated by using a combination of spectroscopic techniques and comparison of experimental and calculated electronic circular dichroism (ECD) data. The MTT experiments showed that (E)-resveratrol (7) could inhibit viability of MH7A cells with the IC value of 12.5 μM. Compound 7 was able to block MH7A cell proliferation and was associated with G/G-phase cell cycle arrest. Flow cytometric analysis showed that the treatment by 7 significantly induced the proliferation of MH7A cells in a dose-dependent manner.