iNOS Inhibitory Activity of Sesquiterpenoids and a Monoterpenoid from the Rhizomes of <i>Curcuma wenyujin</i>

Eleven new sesquiterpenoids, wenyujinins A–K (<b>1</b>–<b>11</b>), and a new monoterpenoid, wenyujinin L (<b>12</b>), were isolated from the rhizomes of <i>Curcuma wenyujin.</i> Their structures and relative configurations were elucidated using 1D and 2D NMR, X-ray crystallographic analysis, and HRESIMS data. The absolute configurations of <b>1</b>, <b>2</b>, <b>3</b>, <b>4</b>, <b>6</b>, <b>8</b>, <b>9</b>, and <b>10</b> were determined by comparison of the experimental and calculated ECD spectra. The absolute configuration of <b>5</b> was determined from the ECD data of the [Rh₂(OCOCF₃)₄] complex, whereas those of <b>7</b> and <b>12</b> were determined from the ECD spectra of the compounds alone. Compounds <b>7</b> and <b>7a</b> strongly inhibited the induction of NO production by LPS, with IC₅₀ values of 7.6 and 8.5 μM, respectively. Compounds <b>6</b> and <b>10</b> moderately inhibited NO production with IC₅₀ values of 47.7 and 48.6 μM, respectively