Covering: January 2007 to December 2009. Previous review: Nat. Prod. Rep., 2008, 25, 555–611

This review describes 796 new examples of naturally occurring flavonoids found either as aglycones or glycosides, comprising flavones, flavonols, chalcones, dihydrochalcones, aurones, flavanones, dihydroflavonols, and anthocyanins. The main topics addressed are source, identification, biological activity, biosynthesis, synthesis, and ecological or chemosystematic significance, and 562 references are cited.