Formation of Acetaldehyde from L-Ascorbic Acid and Related Compounds in Various Oxidation Systems

Article abstract of DOI:10.1021/jf00054a047

The quantities of acetaldehyde formed from L-ascorbic acid, L-threonic acid, and D-erythrose upon oxidation with Fenton's reagent and upon UV irradiation were determined by gas chromatography.When 10 μmol of L-ascorbic acid was oxidized with Fenton's reagent, 316 nmol of acetaldehyde was recovered.When 10 μmol of L-ascorbic acid was irradiated (λ=300 nm) for 12 h, 297 nmol of acetaldehyde was produced.Upon oxidation with Fenton's reagent, L-threonic acid (10 μmol) and D-erythrose (10 μmol) produced 112 and 81.5 nmol of acetaldehyde, respectively.Acetaldehyde was formed from D-erythrose but not from L-threonic acid by photolysis, suggesting that acetaldehyde formation involved a Norrish type II reaction.Acetaldehyde was also formed from aqueous solutions of L-asorbic acid (122 nmol/10μmol), D-erythrose (37.0 nmol/10μmol), or L-threonic acid (27.9 nmol)/10μmol) with the presence of Fe²⁺ at 37 deg C under an air stream.This study is the first to report formation of acetaldehyde from ascorbic acid. Keywords: Antioxidant; acetaldehyde; ascorbic acid; low-density lipoprotein