An attempt to separate vitamin B2 from vitamin B1 in yeast and a comparison of its properties with those of the antineuritic vitamin B1

Abstract

The authors find, during the preparation from yeast of Peters and Kinnersley''s antineuritic (vitamin B1) concentrate, that the removal of the heat-stable (anti-pellagra) vitamin B2 takes place chiefly during precipitation with Pb acetate. From this precipitate vitamin B2 can be recovered by decomposition with H2S and, by appropriate adjustment of the PH at which these processes are conducted, is sometimes obtained uncontaminated with vitamin B1. This result is not constant, however, and seems to depend on the relative amounts of the 2 vitamins in the original yeast. Experiments with yeast extracts containing vitamins B1 and B2 showed (1) that both dialyze through a cellophane membrane; (2) that vitamin B2 is destroyed more quickly than vitamin B1 by irradiation with ultra-violet light; (3) that vitamin B1 is soluble, and vitamin B2 insoluble, in strong alcohol (82-95% by weight).