Bioassay-guided isolation of cyclooxygenase-2 inhibitory and antioxidant phenylpropanoid derivatives from the roots of Dendropanax dentiger

The root of Dendropanax dentiger (Harms) Merr. is a traditional Chinese medicine that has been used to treat inflammation-related diseases with little scientific validation. In this study, a bioassay-guided phytochemical investigation of D. dentiger led to the isolation of 19 phenylpropanoid derivatives including one new compound ( 1 ) and 18 known ones ( 2 – 19 ). Their structures were elucidated by NMR and HRMS as well as comparison with literature data. The ability of cyclooxygenase-2 (COX-2) inhibition and antioxidant of all isolated compounds were measured in vitro . Chlorogenic acid derivatives ( 14 – 19 ) exhibited outstanding COX-2 inhibitory (IC 50  = 5.1–93.4 μM) and antioxidant (IC 50  = 13.2–31.9 μM) activities. Moreover, the tight structure-activities relationships were proposed. This is the first report on the COX-2 inhibitory activity of phenylpropanoids and D. dentiger .