Chemical constituents from the aerial parts of <i>Rubia cordifolia</i> L. with their NO inhibitory activity

Abstract

A new naphthoquinone derivative (<b>1</b>) together with twenty-three known compounds (<b>2</b>-<b>24</b>), were isolated from the aerial parts of <i>Rubia cordifolia</i> L. Their structures were elucidated on the basis of NMR and HR-ESIMS data. Compounds <b>1</b>-<b>13</b> were assessed for their inhibitory effects on NO production in LPS-stimulated RAW 264.7 macrophage cells. Compounds <b>2</b>-<b>6</b> exhibited significant inhibitory activities with IC₅₀ values of 21.37, 13.81, 24.56, 20.32, and 30.08 μmol·L^-1, respectively.