MULTIPLICITY OF THE FOLIC ACID-ACTIVE FACTORS OF BLOOD

Abstract

Previouswork in this laboratory (2) has shown that under proper conditions human blood yields much higher folic acid activity values than those found by prior authors.Microbiological responses indicated more than one factor to be involved.According to the evidence, neither folacin (pteroylglutamic acid), nor pteroyltriglutamic acid, nor folinic acid seemed to be a major component of FS (the designation adopted for the active material).It was also shown (3) that FS is not present as such in blood but results from the interaction, during and after hemolysis, of factors contained in erythrocytes and plasma.The preceding report (3) deals with a study of the precursors, and the present one discusses the end-products (FS).The preparation of stable concentrates of FS and their fractionation will be described.It will be shown that six or more folic acid-like compounds appear to be involved, and their relation to known factors will be considered.EXPERIMENTAL AnaZyticaZ-As previously described (3), FS activities are measured with Lactobacillus casei and the results are expressed in micromicromoles.The same system is used to measure and express Streptococcus faecalis and Leuconostoc citrovorum activities.Starting