Chemistry of ascorbic acid resonance-stabilized nature of its own radical ion, called semidehydroascorbate. The net reaction is: On exposure to oxygen, ascorbic acid will undergo further oxidative decomposition to various products including diketogulonic acid, xylonic acid, threonic acid and oxalic acid. Reactive oxygen species are damaging to animals and plants at the molecular level due to their possible interaction with nucleic acids, proteins, and lipids. Sometimes these radicals initiate chain reactions. Ascorbate can terminate these chain radical reactions by electron transfer. The oxidized forms of ascorbate are relatively unreactive and do not cause cellular damage. However, being a good electron donor, excess ascorbate in
L-gulonolactone oxidase deficiency living in a malarial infested environment". He based his observation on evidence which indicates that G6PD deficient individuals display enhanced sensitivity to ascorbic acid induced hemolysis. Studies of human diseases have benefited from the availability of small laboratory animal models. However, the tissues of animal models with a GULO gene generally have high levels of ascorbic acid and so are often only slightly influenced by exogenous vitamin C. Guinea pigs, for instance, are a popular human model but lost the ability to synthesize L-gulono-gamma-lactone oxidase 20 million years ago. This is a major handicap for studies involving the endogenous