Abstract
The effects of sugar compounds of riboflavin (riboflavinylglucoside, riboflavinylgalactoside and riboflavinyltrioside) and of its phosphorus compounds (riboflavin mononucleotide and riboflavin diphosphate) on the formation of kojic acid from dihydroxyacetone by the riboflavinless mutant of Aspergillus oryzae were compared. It was found that all riboflavin glycosides accelerated kojic acid formation very remarkably, as might have been expected. Especially with riboflavinyltrioside, nearly fourfold acceleration was observed, while flavin phosphates revealed inhibiting effects on kojic acid formation. It was suggested that riboflavinyltrioside would be produced by the transglycosidase of Aspergillus oryzae and that it would be a most probable intermediate product in the biosynthesis of kojic acid.
