Abstract
To investigate the metabolism of riboflavin, [2-14C]riboflavin was administered orally to a rat. The urine pooled for 24 h after administration was fractionated by paper and silica gel thin layer chromatographies using various solvent systems. Among the radioactive metabolites, riboflavinyl glucoside was found along with 7-carboxy lumichrome and 8-carboxy lumichrome. The radioactivity of riboflavinyl glucoside comprised about 6% of the total radioactivity excreted in the urine during 24h.