Undergraduate Research Participant, 1962–1963, in an Undergraduate Research Participation Program
Solution phase interaction of nicotinamide with ascorbic acid
Article first published online: 22 SEP 2006
Copyright © 1963 Wiley-Liss, Inc., A Wiley Company
Journal of Pharmaceutical Sciences
Volume 52, Issue 10, pages 941–945, October 1963
How to Cite
Guttman, D. E. and Brooke, D. (1963), Solution phase interaction of nicotinamide with ascorbic acid. J. Pharm. Sci., 52: 941–945. doi: 10.1002/jps.2600521006
- Issue published online: 22 SEP 2006
- Article first published online: 22 SEP 2006
- Manuscript Accepted: 12 MAR 1963
- Manuscript Received: 18 FEB 1963
- Special Projects in Science Education Section, Division of Scientific Personnel and Education, National Science Foundation, Washington, D. C.
A study was made of what appears to be a charge-transfer interaction that is responsible for the instantaneous generation of a yellow color in aqueous solutions containing nicotinamide and ascorbic acid. Spectral studies were utilized to elucidate some of the factors that influence the interaction. Analysis, by the method of continuous variation, showed that a 1:1 complex was formed. The extent of association was pH dependent and exhibited a maximum at a pH of approximately 3.8. The pH dependency was compared with that of the 3-carbamyl-1-methyl-pyridinium chloride-ascorbic acid system and indicated that the interactants were protonated nicotinamide and ascorbate anion. Association constants, at a number of different temperatures, were determined by using the Benesi-Hildebrand treatment of spectral data. The standard enthalpy change that resulted from association was estimated to be −1,500 cal.