Formation of Superoxide Anion in the Autoxidation of L-Ascorbic Acid in the Presence of Heavy Metal Ions

중금속 이온 존재하에서의 아스코르빈산 자동산화 과정에서 $O_2\bar{{\bullet}}$ 생성

  • Kim, Mi-Ok (Department of Food Science and Technology, Kyungpook National University)
  • 김미옥 (경북대학교 식품공학과)
  • Published : 2001.06.30

Abstract

Formation of superoxide anion $O_2\bar{{\bullet}}$ in the autoxidation of L-ascorbic acid (AsA) in the presence of heavy metal ions were determined. The generation of $O_2\bar{{\bullet}}$ was studied by using superoxide dismutase (SOD) in aqueous and buffer solution, and using nitro bule tetrazolium (NBT) in methanol solution. The remaining amount of AsA was significantly higher in the presence of SOD than in its absence. It suggested that SOD stabilizes AsA in aqueous and buffer solution because of scavenging $O_2\bar{{\bullet}}$ formed during the autoxidation reaction of AsA in the presence of heavy metal ions. NBT has an absorption maximum at about 560 nm in methanol solution. The absorbance at 560 nm increased during the oxidation of AsA, suggested the formation of $O_2\bar{{\bullet}}$in methanol solution. Thus, the formation of $O_2\bar{{\bullet}}$ was confirmed during the autoxidation of AsA not only in aqueous solution but also in methanol solution in the presence heavy metal ions.

Keywords

L-ascorbic acid;autoxidation;superoxide anion;heavy metal ions