A new sesquiterpene from the leaves of Heritiera littoralis Dryand with nitric oxide inhibitory activity.

An undescribed sesquiterpene beibuxsocapsa A (1), together with six known compounds, ergosterol (2), 22E,24R-ergosta-7,22-diene-3β,5α,6β-triol (3), stigmasterol (4), stigmast-4-en-3-one (5), stigmast-4-en-6β-ol-3-one (6), and loliolide (7) were successfully obtained from the CH2Cl2 (dichloromethane) extract prepared from the leaves of the Chinese mangrove plant, Heritiera littoralis Dryand (Malvaceae). Their structures were unambiguously elucidated via thorough spectroscopic examinations corroborated by comparisons with pertinent literature. The absolute configuration of compound 1 was precisely determined through single-crystal X-ray diffraction of its modified structure. Furthermore, the ability of compounds 1-7 to suppress NO (nitric oxide) production in RAW-264.7 macrophages stimulated by LPS (lipopolysaccharide) were evaluated as an indicator of their anti-inflammatory activity. Notably, Compound 1 significantly reduced NO production in LPS-stimulated cells, with an IC50 value of 9.22 μM.