Abstract
The separation of naturally occurring folates is achieved by column chromatography on DEAE-cellulose (diethylaminoethyl-C) and on TEAE-cellulose (triethylaminoethyl-C), and the separated fractions are quantitated and identified by microbiological assay. However, the resolution of such columns is insufficient for adequate separation of several of the folate coenzymes. The interconversion of a number of folate coenzymes by an alternative means, such as by radiolabel techniques, a chromatographic system is required, by which the identity of compounds is unambiguously assigned from their elution position relative to known markers. A method––DEAE-Sephadex by which folate coenzymes is resolved by column chromatography and by which their elution is more simply monitored, despite the presence of reducing agents that interfere with the ultraviolet absorbance spectra of folate coenzymes but which may be necessary to prevent their oxidation during chromatography is described. For the identification of folate coenzymes which may be radiolabeled during studies of the interconversion of the reduced folates, satisfactory markers are found to be 0.5 micromole of p-aminobenzoylglutamate and 2 micromoles each of THF (tetrahydrofuran) and 5-formyl-THF.