Natural 2,5-bisaryltetrahydrofuran lignans: Platelet-activating factor antagonists

Lignans are a class of naturally occurring compounds characterized by bonding of two aryl propanoids at the 2-position. Recently, an increasing significance of the biological activities of these compounds has been recognized. Members of 2,5-bisaryltetrahydrofuran class of lignans are antagonists of the potent bioactive phospholipid, platelet activating factor (PAF). In this review, a survey of the occurrence, physical properties of all known bisaryltetrahydrofurans and reported biological activities as PAF antagonists is given.