De la chimie des ptérines. 78e Communication.. Synthèse de l'ester tripolyphosphorique de la tétrahydro-5, 6, 7, 8-D-néoptérine. Essai d'interprétation de la biosynthèse de la L-sépiaptérine

Synthesis of 5, 6, 7, 8-Tetrahydro-D -neopterine tripolyphosphate. Attempt to Interpret the Biosynthesis of L -Sepiapterine The synthesis was achieved by phosphorylation of tetrahydro-5, 6, 7, 8-D -neopterine with polyphosphoric acid. The product is sensitive to light, moisture and oxidation like the other tetrahydropetrines. After oxidation in aqueous solution, D , L -sepiapterine was isolated in 5% yield. The oxidation of non-phosphorylated tetrahydro-5, 6, 7, 8-D -neopterine under the same conditions led to D -sepiapterine without inversion of the configuration. These findings were used to give a tentative explanation for the biosynthesis of natural L -sepiapterine from the D -neopterine.