Dihydrochalcone metabolism in the rat: trihydroxylated derivatives related to phloretin

The metabolism of 2',4',4-, 2',6',3- and 2',6',4-trihydroxydihydrochalcone was studied in rats. Approx. 25-35% of the oral dose (0.75 mmol/kg) was excreted in the urine during a five to six day period. The unchanged compounds were the most prominent urinary excretion products and were also present in large amounts in the faeces. Other metabolites of the three dihydrochalcones included minor amounts of hydroxylated products and subsequent O-methylated derivatives as well as minor amounts of degradation products (resorcinol and hydroxyphenylpropionic acids) arising from scission of the compounds by the normal gut microflora. The present results support the view that the degradative metabolism of dihydrochalcones involves scission leading to equal amounts of products derived from the A- and B-ring regions of these flavonoids.