3-Hydroxyanthranilic AcidKynurenic Acid3-Hydroxyanthranilate 3,4-Dioxygenaseortho-AminobenzoatesKynurenineXanthurenatesOxazinesStreptomyces antibioticusQuinolinic AcidTryptophanNiacinOxygenasesIndoleamine-Pyrrole 2,3,-DioxygenaseDioxygenasesStreptomycesBasidiomycotaFree Radical ScavengersTransaminasesKynurenine 3-MonooxygenaseChromatography, Thin LayerExcitatory Amino Acid Antagonists