Abstract
The melanine tissue of frog skin contains riboflavin and several pterines. A violet fluorescent substance having the Rf value of 0.41 was recognized on the paper chromatograms (developed with n-butanol-acetic acid-water) with the extract of this tissue obtained by the treatment with 5% ammonia solution at 80℃ for 15minutes. The above treatment of pure riboflavin solution gave also the identical spot with that of the tissue extract. This substance is a new one, quite different from riboflavin or its known derivatives.
