New metabolites of riboflavin appear in human urine.
By surveying compounds having isoalloxazine derived from flavins on a high performance liquid chromatogram with fluorescence detection, two new flavin derivatives were found in human urine. These two compounds were purified by partition chromatography on a cellulose column and by paper chromatography with several solvent systems, and their structures were determined to be 7 alpha-hydroxyriboflavin and 8 alpha-hydroxyriboflavin. The relative distributions, measured by high performance liquid chromatography, of 7 alpha- and 8 alpha-hydroxyriboflavin, riboflavin, and hydroxyethylflavin and its derivative were calculated to be 31.1, 5.0, 25.6, 4.9, and 21.9%, respectively, to total flavins in normal human urine obtained in early morning. The excretion of 7 alpha- and 8 alpha-hydroxyriboflavin in human urine indicates the occurrence of a metabolic pathway of the isoalloxazine ring of flavin at its 7 alpha and 8 alpha positions.
D000328:Adult; D002851:Chromatography, High Pressure Liquid; D002854:Chromatography, Paper; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D012256:Riboflavin / Q000031:analogs & derivatives* / Q000652:urine*
C038139:8-hydroxymethylriboflavin; C038138:7-hydroxymethylriboflavin; D012256:Riboflavin