CHROMATOGRAPHIC DETERMINATION OF FLAVIN DERIVATIVES IN BAKERS-YEAST

The presence of flavin derivatives in baker's yeast was tested by high -performance liquid chromatography and thin-layer chromatography. In y east samples, besides flavin adenine dinucleotide and flavin mononucle otide, small amounts of riboflavin and traces of 10-formylmethylflavin have been found. Total amount of flavins was calculated to be 17.9+/- 2.9 mu g/g of fresh yeast. The distribution of flavin adenine dinucleo tide, flavin mononucleotide, riboflavin and 10-formylmethylflavin in t otal flavin content were estimated to be 71.5%, 25.8%, 1.7% and below 0.05%, respectively. In some samples we have additionally detected sma ll amounts (0.8% of total flavins) of new flavin derivative which has been identified as 4',5'-riboflavin cyclic phosphate by means of its c hromatographic and chemical behaviour. This compound seems to be a pro duct of flavin adenine dinucleotide degradation and probably has been earlier mistaken for flavin mononucleotide. Its formation is dependent on pH conditions. (C) 1998 Elsevier Science B.V. All rights reserved.