Neopterin und Neopterin-3′-phosphat als Vorläufer der Folsäure bei Mycobacterium smegmatis

Abstract

Extracts of Mycobacterium smegmatis synthesise dihydro-pteroate and dihydro-folate from dihydro-pteridine-6-carbinol as well as from dihydro-neopterin and dihydro-neopterin-3′-phosphate. The 7-isomers of the pteridine precursors are neither substrates nor inhibitors of folate biosynthesis. Side-chain 14C-labelled dihydro-neopterin yields similarly labelled dihydro-folate. From the isotopic data it is concluded that a two-carbon fragment is split off the chain and that C-1′ of dihydroneopterin becomes the bridging methylene group between the pteridine and the p-aminobenzoyl moiety of the compound produced.