Untersuchung über die Biosynthese der Pterine bei Drosophila melanogaster

Larvae of the wild type of Drosophila melanogaster and of two mutants («trosy»)and («sepia») were fed with glycine‐ [2‐14C], formate‐ [14C] glucose‐ [U‐14C], glucose‐(l‐14C), glucose‐(6‐14C), fructose ‐[U‐14C] and DL‐lactate‐ [1‐14C]. After the hatching of the flies isoxanthopterine, drosopterine, sepiapterine and uric acid were isolated by paper chromatography and their specific activities were determined. The carbon atoms 8 and 9 of the pyrazine ring were isolated as oxalic acid after degradation of the pterine with chlorine followed by acid hydrolysis (method of WIELAND & TARTTER). The pyrimidine ring is not attacked by this process. This procedure was tested by the degradation of the synthetic isoxanthopterines‐ [8‐14C] and ‐[514C].