The genus of Forsythia (Oleaceae), composing ca. 10~15 species, is mostly native to eastern Asia and used in oriental traditional
medicines. Phytochemical investigations on Forsythia species have shown that triterpenoids, lignans, flavonoids, phenylethanoid
glycosides and C6-C2 natural alcohols, accumulated mainly in the fruits, are the major components. Many studies have elucidated that
phenolic compounds, including lignans, phenylethanoid glycosides and flavonoids are responsible for the various biological activities of
the herbal medicine. This review lists 141 chemical constituents as well as their biosynthetic pathway, bioactivities and quality control as
reported until September, 2011 (104 references).