[Sesquiterpenoids from rhizome of Homalomena occulta]

Twelve compounds were isolated from alcohol extracts of the rhizome of Homalomena occulta by using various chromatographic techniques including column chromatography onsilica gel and C₁₈ reverse-phase silica gel, and semi-preparative HPLC. Their structures were identified by physico-chemical properties and spectroscopic data analysis as 3α, 7α-dihydroxy-cadin-4-ene (1), 3-oxofabiaimbricatan (2), 3β, 4α-dihydroxy-7-epi-eudesm-11(13)-ene (3), integrifonol A(4), 1β, 6β-dihydroxy-7-epi-eudesm-11(13)-ene (5), 4β, 7β, 11-enantioeudesmantriol (6), epi-guaidiol (7), oplopanone(8), (-)-1β, 4β, 6α-trihydroxy-eudesmane (9),2α-hydroxyhomalomenol(10), (-)-T-muurolol (11) and hamalomenol A(12). Compounds 1-7 were obtained from the genus Homalomena for the first time and 11-12 were firstly reported from the species. Additionally, compounds 3, 5 and 8 displayed inhibitory effects against the lipopolysaccharide (LPS)-induced nitric oxide (NO) production in mouse macrophage RAW264.7 cells with IC₅₀ values of 6.51, 3.25, 7.78 μmol•L⁻¹, respectively.