New Triterpenoids from the Leaves of Heritiera littoralis and Their Anti-Inflammatory Activity

Six new triterpenoids, heritieras C-H (<b>1</b>-<b>6</b>), along with thirteen known triterpenoids (<b>7</b>-<b>19</b>), were isolated from the leaves of <i>Heritiera littoralis</i>. Their structures were identified by spectroscopic analysis, including 1D and 2D nuclear magnetic resonance (NMR), high-resolution electrospray ionization mass spectrometry (HRESIMS), and by comparison with the literature. Anti-inflammatory activity of the isolates was evaluated using the lipopolysaccharide (LPS) stimulated RAW 264.7 cell model. Among the isolated triterpenoid, compounds <b>1</b>, <b>12</b>, <b>16</b>, <b>17</b>, and <b>18</b> demonstrated inhibitory activity against nitric oxide (NO) release, in which compound <b>18</b> exhibited the best activity with an IC₅₀ value of 18.13 μM. The potential anti-inflammatory mechanism was investigated using molecular docking. The triterpenoids from <i>H. littoralis</i> could be served as potential candidates for the development of new anti-inflammatory agents.