3-Hydroxyanthranilic Acid3-Hydroxyanthranilate 3,4-Dioxygenaseortho-AminobenzoatesKynurenineOxazinesStreptomyces antibioticusXanthurenatesTryptophanNiacinQuinolinic AcidOxygenasesIndoleamine-Pyrrole 2,3,-DioxygenaseDioxygenasesStreptomycesBasidiomycotaFree Radical ScavengersChromatography, Thin Layer