Four new phenolic constituents from root barks of .

The , also known as "Feng Dan" have a crucial role in folk medicine to treat lumbar muscles strain, knee osteoarthritis and cervical spondylosis. In this study, four new phenolic compounds, specifically Paeoniaostiph A-E (-) phenolic compounds were characterised through spectroscopic techniques, including 1D and 2D NMR, HRESIMS, UV, IR, and electronic circular dichroism computations to explore their structures. Cytotoxicity and NO production inhibition of the new phenolic compounds were also studied. The results of the cytotoxicity experiment showed that compound is cytotoxic to two human cancer cell lines with IC values ranging from 13.3 to 13.5 μM. Compounds and showed certain inhibitory activity on NO production. This is the first report on isolating the components from natural sources.