The present review describes 108 new examples of naturally occurring flavans and flavanones having cytotoxic potential, which have been reported during the period of 2005 to mid-2020. These compounds are found either as aglycones or as glycosides, comprising flavans, flavanones, isoflavanones and miscellaneous flavanones (homo- and bi-flavanones). The main topics addressed in this review are source, structure, and cytotoxic activity in detail and the structure-activity relationship.
Keywords: Natural flavans and flavanones, cytotoxicity, anticancer activity, aglycones, glycosides, structure-activity relationship.