Affordable Access

Publisher Website

Electronic structures and spectra of two antioxidants: uric acid and ascorbic acid

Authors
Journal
Journal of Molecular Structure THEOCHEM
0166-1280
Publisher
Elsevier
Publication Date
Volume
377
Issue
3
Identifiers
DOI: 10.1016/s0166-1280(96)90992-6
Keywords
  • Uric Acid
  • Ascorbic Acid
  • Vitamin C
  • Dehydroascorbic Acid
  • Antioxidant

Abstract

Abstract Electronic absorption and fluorescence spectra of aqueous solutions of two well known antioxidants, uric acid and ascorbic acid (vitamin C), have been studied at different pH. The observed spectra have been interpreted in terms of neutral and anionic forms of the molecules with the help of molecular orbital calculations. The N 3 site of uric acid has been shown to be the most acidic. Fluorescence of uric acid seems to originate from an anion of the molecule in a wide pH range. Around pH 3, both the neutral and anionic forms of ascorbic acid appear to be present in aqueous solutions. In aqueous media, ascorbic acid appears to get converted easily to its dehydro form and this conversion does not seem to be reversible. An anion of dehydroascorbic acid seems to be formed on heating dehydroascorbic acid in aqueous solutions.

There are no comments yet on this publication. Be the first to share your thoughts.