Anthranilic acid release in adenosine-inhibited cultures of Saccharomyces cerevisiae and its inhibition by thiamin

Adenosine, at 1 mM concentrations or above, was found to have a fungistatic effect on Saccharomyces cerevisiae. A substance with amethyst fluorescence was detected in the medium of adenosine-inhibited cultures of S. cerevisiae. This compound was isolated and physicochemically identified as anthranilic acid. Both the inhibition of growth and release of anthranilic acid induced by adenosine were abrogated by thiamin or by the pyrimidine portion of thiamin, 2-methyl-4-amino-5-hdroxymethyl-pyrimidine (hydroxymethyl-pyrimidine); the latter was found to restore intracellular thiamin content that had been reduced by adenosine. It was demonstrated that effects of thiamin and hydroxymethylpyrimidine on S. cerevisiae cultured with adenosine resulted from their inhibition of adenosine uptake by growing yeast cells.