Ultra-Violet Absorption Spectrum and Chemical Structure of Vitamin B₁

Abstract

THE experiments of Heyroth and Loofbourow have established a close correlation between the physiological activity of concentrates of vitamin B₁ (after eliminating inactive purines and pyrimidines, which absorb in the same spectral region), and the intensity of the absorption band at 2600 A. They have thus provided a welcome confirmation of the proof which we gave in our letter to NATURE of May 14, that vitamin B₁ is characterised by an absorption covering the mercury line at 2537 A. The detection in their concentrates of inactive substances which absorb light of similar wave-length is of great value as a guide to the conditions under which the intensity of the band may be used as a measure of the concentration of the vitamin; but the identification of the characteristic band by the method of monochromatic irradiation was independent of the presence or absence of these impurities in the apparently homogeneous crystals which were used in our experiments.