Chalcones (1,3-diphenyl-2-propen-1-one) and especially chalcones bearing oxygenated function on the aromatic rings are the precursors of all the flavonoids. 1 They are biologically active molecules found in human diet as they are accumulated in many plants and vegetables. 2 During the biosynthesis, chalcones are cyclized stereospecifically into the corresponding chroman-4-one, also called flavanone, by the enzyme chalcone isomerase (CHI, EC ...