Investigations on the preparation and behaviour of vitamin B1 concentrates from yeast

Abstract

Adenine, guanine, uracil, dl-thyroxine, histamine and adrenaline cannot replace vitamin B1 in the diet of rats. A fairly standardized method of concentration of vitamin B1 is described by which, starting from brewer''s yeast, a preparation can be obtained at the platinum stage which promotes good growth in rats in a daily dose of 0.075-0.1 ingm. when supplemented by vitamin B. Its pigeon-curative day-dose is of the order of 0.047 mgm. No clear-cut answer has been obtained to the question whether fractionation by gold chloride would provide any evidence for the splitting of vitamin B1. The rat-growth tests and pigeon-curative tests of these fractions show serious discrepancies. Vitamin B1 does not appear to be closely chemically related to co-zymase. Its relation to secretin and "bios" is discussed. Some vitamin B1 concentrates are optically inactive and give negative nin-hydrin and Adamkiewicz-Hopkms reactions. The Pauly reaction given by the purer yeast concentrates is comparatively weak. Vitamin B1 is not apparent!}" precipitated by flavianic acid from a fairly concentrated preparation. The absorption spectra of certain concentrates are described.