The bioassay was directed to the fractionation of the methanol extract of the rhizomes of Zingiber officinale Roscoe leading to the isolation of a new antioxidant cyclic diarylheptanoid. The structure of the new compound was established as 1, 5-epoxy-3-hydroxy-1-(3,4-dihydroxy-5-methoxy-phenyl)-7-(3,4-dihydroxyphenyl) heptane (1) on the basis of MS, 1D and 2D-NMR experiments.