Two new bioactive lignans from leaves and twigs of <i>Cleistanthus concinnus</i> Croizat

<p>Two new lignans (<b>1</b>–<b>2</b>), along with five known compounds (<b>3</b>-<b>7</b>) with different structures were isolated from leaves and twigs of <i>Cleistanthus concinnus</i> Croizat. The new lignans were elucidated as (7′R,8′S)-3,3′,5′-trimethoxy-4,4′-dihydroxy-7-en-7′,9- epoxy-8,8′-lignan (<b>1</b>) and (7′R,8′S)-3,3′-dimethoxy-4,4′-dihydroxy-7-en-7′,9-epoxy-8, 8′-lignan (<b>2</b>) by comprehensive spectroscopic analysis including 1D and 2D NMR as well as HREIMS and comparing their NMR data with known compounds in the literature. Among these isolated compounds, compound <b>1</b>, <b>2</b>, <b>3</b>, and <b>6</b> were tested for anti- inflammatory effects by inhibiting NO production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Compound <b>1</b>, <b>2</b>, and <b>6</b> exhibit NO inhibitory activity.</p> <p></p>