The Ultraviolet Absorption of Vitamin B c and Xanthopterin

Abstract

Concentrates containing 5 to 10% of vit. Bc exhibited specific absorption in the U.V. region. This was characteristic of the vit. The intensity and position of the absorp. bands were dependent on pH. These characteristics suggest the presence in the Bc molecule of a pyrimidopyrazine ring structure (pterins). U.V. absorp. curves of synthetic and natural xanthopterin were made and were generally similar to those of vit. Bc. There were some marked dissimilarities. Vit. Bc was irradiated with an H-4 lamp without filter and absorp. curves were made in aq. soln. at pH of 11. The vit. was only moderately sensitive to U.V. illumination.