Ist 3.4-Dioxy-anthranilsäure Zwischenprodukt bei der biologischen Synthese von Nicotinsäure?

Abstract
To elucidate the mechanism of niacin formation from tryptophan 3,4-dihydroxyanthranilic acid was synthesized. It was as inactive as 3-hydroxyanthranilic acid in liver slices or Neurospora crassa ATCC 10767 to form niacin. dl-3,4-Dihydroxy-kynurenine is split by kynureninase to form alanine.