A new cadinane-type sesquiterpenoid from Commiphora myrrha

Five cadinane-type sesquiterpenoids were isolated from the n-hexane extract of Commiphora myrrha by using various chromatographic techniques, including silica gel, ODS and semi-preparative HPLC. Their structures were identified by physicochemical properties and spectroscopic data. These compounds were defined as (3S,4R)-3,9-dimethoxymyrrhone (1), 9-methoxymyrrhone (2), myrrhone (3), commiterpene B (4) and comosone Ⅱ (5). Compound 1 is a new compound, of which the absolute configuration was established by single crystal X-ray crystallographic analysis. Compound 5 is firstly isolated from the Commiphora genus.