Natural retrochalcones: rare compounds with diverse biological activities

Abstract Retrochalcones represent a group of secondary metabolites only rarely occur in nature. Although retrochalcones are not very abundant as can be found especially in Glycyrrhiza species, several recent studies report their presence also out of genus Glycyrrhiza . Therefore, this review describes the biosynthesis, occurrence, and biological activities of natural retrochalcones. In addition, confusing information found in the literature is pointed out and clarified. Search in the literature revealed 18 compounds classified as retrochalcones possessing anticancer, anti-inflammatory, antioxidant, neuroprotective, cardioprotective, hepatoprotective, and antimicrobial activities at very least. Biological activities are reported with emphasis on those of neglected retrochalcones to arouse the attention of scientists to focus more on these unique substances. This review demonstrates that retrochalcones display diverse biological activities with even more diverse mechanisms of action and could therefore find application in various fields of medicine and cosmetics.