Anti-emetic principles of Magnolia obovata bark and Zingiber officinale rhizome.

Magnolol and honokiol, biphenyl compounds, were isolated as anti-emetic principles from the methanolic extract of Magnolia obovata bark. [6]-, [8]-, and [10]-shogaols and [6]-, [8]-, and [10]-gingerols were isolated from the methanolic extract of Zingiber officinale rhizome as anti-emetic principles. Some phenyl-propanoids with allyl side-chains were found to show the same activity. They inhibited the emetic action induced by the oral administration of copper sulfate pentahydrate to leopard and ranid frogs.