Vitamin C of mannose or galactose to ascorbic acid. In animals, the starting material is glucose. In some species that synthesize ascorbate in the liver (including mammals and perching birds), the glucose is extracted from glycogen; ascorbate synthesis is a glycogenolysis-dependent process. In animals that cannot synthesize vitamin C, the enzyme -gulonolactone oxidase (GULO), that catalyses the last step in the biosynthesis, is highly mutated and non-functional. The biosynthesis of ascorbic acid in vertebrates starts with the formation of UDP-glucuronic acid. UDP-glucuronic acid is formed when UDP-glucose undergoes two oxidations catalyzed by the enzyme UDP-glucose 6-dehydrogenase. UDP-glucose 6-dehydrogenase uses the co-factor NAD
Ferulic acid is an antioxidant in vitro in the sense that it is reactive toward free radicals such as reactive oxygen species (ROS). ROS and free radicals are implicated in DNA damage, cancer, and accelerated cell aging. If added to a topical preparation of ascorbic acid and vitamin E, ferulic acid may reduce oxidative stress and formation of thymine dimers in skin. There is also a small amount of research showing oral supplements of ferulic acid can inhibit melanin production in the process of skin whitening. It is used as a matrix for proteins in MALDI mass spectrometry analyses. Ferulic acid Ferulic