A New Hydroxystilbene Tetramer Named Isohopeaphenol from Vitis vinifera 'Kyohou'

A new hydroxystilbene tetramer named isohopeaphenol was isolated from the cork of Viris viriiJern 'Kyohou' and its structure was elucidated on the basis of spectroscopic evidence.In our previous papers,'.'we reported the isolation and structures of hydroxystilbene oligomers and lupanetype triterpenes from the cork of Vilis vinifern 'Kyohou' cultivatedin WakayamaPrefecture.Our continuing investigation of the constituents or the above plant led to the isolation of a new hydroxystilbene t e m e r named (-)-isohopeaphenol (1) together with (+)-hopeaphenol (2).In this paper we describe the isolation and structure of isohopeaphenol (I).