Antiallergic activity of aqueous extracts and constituents of Taxus yunnanensis.

The H2O, H2O/MeOH (1:1) extracts from the wood of Taxus yunnanensis showed a remarkable inhibitory effect on induced histamine release from the human basophilic cell line, KU812. The eleven constituents purified from the wood extracts of Taxus yunnanensis were tested by an in vitro histamine release inhibition assay. Among them, secoisolarciresinol and taxiresinol were found to show inhibitory activities. A new neolignan, 2-[2-hydroxy-5-(3-hydroxypropyl)-3-methoxyphenyl]-1-(4-hydroxy-3-methoxyphenyl)propane-1,3-diol, was isolated from the wood of Taxus yunnanensis.