C6H7O6

C6H7O6 is the chemical formula of the ascorbate monoanion, the conjugate base of ascorbic acid (vitamin C). While ascorbic acid itself has the neutral formula C6H8O6, C6H7O6 represents the deprotonated form that predominates in neutral and slightly basic aqueous environments, including biological systems.

In solution, ascorbate exists primarily as the monoanionic species (C6H7O6−) at physiological pH. Ascorbic acid has two acidic protons, with pKa values around 4.1 and 11.6, so the first deprotonation yields the monoanionic form and the second yields a dianion under strongly basic conditions. Ascorbate is a powerful reducing agent and readily undergoes oxidation to dehydroascorbic acid (C6H6O6), a reversible process that underpins its antioxidant role and involvement in cellular redox balance.

Natural occurrence and function: vitamin C is an essential nutrient for humans and many other animals, found abundantly in fruits and vegetables. In biology, ascorbate acts as a cofactor for several dioxygenase enzymes involved in collagen synthesis, iron absorption, and the metabolism of certain neurotransmitters. It also protects cells from oxidative stress by donating electrons to reactive oxygen species and helps regenerate other antioxidants, such as vitamin E.

Applications and related salts: C6H7O6 appears in the context of ascorbate salts, such as sodium ascorbate (C6H7NaO6), which are used as dietary supplements and food antioxidants. Deficiency of vitamin C leads to scurvy, while adequate intake supports collagen formation and overall health.