The Absorption Spectrum of Hexuronic Acid

Abstract

As part of a systematic study¹ of Prof. Szent-Györgyi's ‘hexuronic acid’ we have investigated quantitatively the absorption spectra of hexuronic acid, glycuronic acid, galacturonic acid, tetramethyl γ-fructose, and other carbohydrate derivatives. In view of the fact that hexuronic acid has been identified with vitamin C,² we have paid special attention to the possibility of contamination by small traces of impurity. We find that the single broad band at about 263 mμ reported qualitatively by F. P. Bowden and C. P. Snow³ is found in equal intensity with the sample of hexuronic acid supplied by Prof. Szent-Györgyi and with rigorously purified material. It appears, therefore, that this band is definitely associated with hexuronic acid. The nature of the band in methyl alcohol (c. 0.002 per cent) is indicated by the accompanying table: