Chemical constituents from Alisma plantago-aquatica subsp. orientale (Sam.) Sam and their anti-inflammatory and antioxidant activities.

The chemical constituent investigation of Alisma plantago-aquatica subsp. orientale has led to isolation and identification of thirteen compounds, including one new sesquiterpene, (10S)-11-hydroxy-β-cyperone (1), three sesquiterpenes (2-4), five phenylpropanoids (5-9), and four alkaloids (10-13). We report herein, for the first time, the presence of compounds 2-13 in the genus Alisma. Their structures were established using 1D and 2D NMR and HRESIMS spectroscopic analyses. All the isolated compounds were assayed for their inhibitory activities against nitric oxide production in LPS-induced RAW 264.7 cells and antioxidant activities by DPPH scavenging assay. Compounds 1-13 displayed significant inhibitory effects against NO production at a certain concentration, while compound 5 showed antioxidant activity with IC50 of 55.28 μM. The interactions of compounds 1, 5, and 11 with iNOS were investigated using molecular docking.