Yucca gloriosa (Agavaceae) is used in Indian traditional medicine as an antiallergic drug. The ethanol extract was prepared with aerial parts of Yucca gloriosa (YGE). Gloriosaol isomeric mixtures (GLM) are isolated from the extract, structurally confirmed FIA-MS/MS. Both YGE and GLM are evaluated against ovalbumin-inducedairway