L-gulono-y-lactone oxidase and

L-Ascorbic acid, better known as vitamin C, has the simplest chemical structure of all the vitamins (Figure 18.30). It is widely distributed in the animal and plant kingdoms, and only a few vertebrates—humans and other primates, guinea pigs, fruit-eating bats, certain birds, and some fish (rainbow trout, carp, and Coho salmon, for example)—are unable to synthesize it. In all these organisms, the inability to synthesize ascorbic acid stems from a lack of a liver enzyme, L-gulono-y-lactone oxidase. 

Kawai, T., Nishikimi, M., Ozawa, T., and Yagi, K., 1992, A missense mutation of L-gulono-y-lactone oxidase causes the inability of scurvy-prone osteogenic disorder rats to synthesize L-ascorbic acid, J. Biol. Chem. 267 21973-21976. 

Nakagawa, H., Asano, A., and Sato, R., 1975, Ascorbate-synthesizing system in rat liver microsomes II. A peptide-bound flavin as the prosthetic group of L-gulono-y-lactone oxidase, J. Biochem. (Tokyo) 77 221-232. 

Nishikimi, M., and Udenfriend, S., 1976, Immunologic evidence that the gene for L-gulono-y-lactone oxidase is not expressed in animals subject to scurvy, Proc. Natl. Acad. Sci. USA 73 2066-2068. 

The same flavin occurs at the active center of bacterial thiamine dehydrogenase (Singer and Kenney, 1974, Kenney et al., 1974b) and in L-gulono-y-lactone oxidase from rat liver (Kenney et al., 1976b). 

Horio, F., Shibata, T., Naito, Y., Nishikimi, M., Yagi, K., and Yoshida, A., 1993b, L-Gulono-7-lactone oxidase is not induced in rats by xenobiotics stimulating L-ascorbic acid biosynthesis, J. Nutr. Sci. Vitaminol. 39 1-9. 

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