Sesquiterpenoids from the rhizomes of and their anti-inflammatory activities.

Sixteen sesquiterpenoids including two new ones, homalolides A - B ‒, were firstly isolated from the methanolic extract of the rhizomes of collected in Vietnam. The structures and relative stereochemistry of new compounds were elucidated by 1D-/2D-NMR, IR, UV and HRESIMS analyses. The GCMS experiment demonstrated that homalolide A () is an artifact due to the methylation during methanolic extraction process. All isolates (‒) were tested for their inhibitory activities against lipopolysaccharide-induced nitric oxide production in the RAW 264.7 macrophage cell line. Compounds , , ‒, ‒ displayed moderate inhibitory effect on NO production with IC values ranging from 35.41 to 64.06 μM.