Natural and synthetic xanthonolignoids: chemistry and biological activities.

Natural xanthonolignoids are formed by the coupling of cinnamyl alcohol with an appropriate ortho-dihydroxyxanthone. More than twenty xanthonolignoids have been isolated and synthesized and some interesting pharmacological activities of these compounds have been described. The purpose of this review is to describe the natural occurrence, isolation, structure elucidation and synthesis - both biomimetic and classic - as well as biological activities of xanthonolignoids. Aspects related to biosynthesis will also be considered.