Abstract
The distribution of riboflavin and other fluorescent substances in the skin was studied with 11 species of animals by paper partition chromatography. (1) The forms of riboflavin in the skin of Mammalia or Aves are considerably different from those in the skin of Amphibia. The majority of riboflavin is ester forms of the vitamin (FAD and FMN) in the former, while almost all is free form in the latter. (2) It is interesting that a blue-fluorescent substance having Rf 0.45,which was confirmed to be kynurenine by several tests, is observed in general in the mammalian skin.
