Analysis of the transformation products of dehydro-L-ascorbic acid by ion-pairing high-performance liquid chromatography.
Dehydro-L-ascorbic acid, the oxidation form of L-ascorbic acid, converts nonenzymatically to a variety of transformation products depending upon the incubating conditions. These products, called the ascorbate cascade, possess different absorption spectra and reducing activities. Ion-pairing high-performance liquid chromatography with multiwavelength uv absorption and amperometric electrochemical detection has proven to be a useful technique for the analysis of these products. Separation and characterization in the present investigations reveal three kinds of transformation products: the polymerized intermediates of browning reaction, the reductant possessing an absorption maximum at 345 nm as the six-carbon compound, and erythro-L-ascorbic acid, 2-furoic acid, 3-hydroxy-2-pyrone, 5-methyl-3,4-dihydroxytetrone, reductic acid, and furfural as the five-carbon compound. These products possess an absorption maximum above 240 nm, and most of them are electrochemically active reducing compounds which are derived from nonreducing dehydro-L-ascorbic acid through the processes of delactonization, decarboxylation, and intramolecular rearrangement.
Kimoto
E
E
Department of Chemistry, Faculty of Science, Fukuoka University, Japan.
Tanaka
H
H
Ohmoto
T
T
Choami
M
M
D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002852:Chromatography, Ion Exchange / Q000379:methods; D003683:Dehydroascorbic Acid / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010084:Oxidation-Reduction
D003683:Dehydroascorbic Acid