ENANTIOMERIC SEPARATION OF BIOPTERIN AND NEOPTERIN STEREOISOMERS BY CHIRAL HPLC - APPLICATION TO THE IDENTIFICATION OF NATURAL PTERINS IN PROTOZOANS

The separation of the D and L enantiomers of biopterin and neopterin has been achieved by ligand exchange chromatography using a reversed phase column with a mobile phase containing D-phenylalanine as chiral modifier and Cu(II) as the metal ion. This successful separation has enabled the identification of natural pterins present in various protozoans by comparison with authentic, optically pure compounds. D-monapterin and D-neopterin were identified in the ciliate protozoan Colpidium campylum. L-biopterin has been found, for the first time, in a flagellate protozoan, Astasia longa.