Vitamin C & its Antioxidant Chemistry Ascorbic Acid In the Name of The Most High

Physical data Appearance: white to light yellow crystals or powder Melting point: ca. 193 C (decomposes) Specific gravity: 1.65 Water solubility: high Stability Stable. May be weakly light or air sensitive. Incompatible with oxidizing agents, alkalies, iron, copper. Toxicology May be harmful if ingested in large quantity. May act as an irritant. Orl-Rat LD mg/kg Sucrose Orl-Rat LD mg/kg Sodium Chloride Orl-Rat LD mg/kg Toxicology May be harmful if ingested in large quantity. May act as an irritant. Orl-Rat LD mg/kg Sucrose Orl-Rat LD mg/kg Sodium Chloride Orl-Rat LD mg/kg

Ascorbic Acid is a Di-acid At pH % of vitamin C will be present as AscH -, 0.05% as AscH 2 and 0.004% as Asc 2-. The antioxidant chemistry of vitamin C is the chemistry of AscH -. Ascorbates

AscH - a Donor Antioxidant AscH- donates a hydrogen atom (H· or H+ + e-) to an oxidizing radical to produce the resonance-stabilized tricarbonyl ascorbate free radical. AscH· has a pKa of -0.86; thus, it is not protonated in vivo and will be present as Asc·-.

Ascorbate a versatile, water soluble, donor antioxidant. A weakly oxidizing and weakly reducing radical

Reactive Oxygen and Nitrogen Radicals (both inorganic and organic) Reactive oxygen Radicals Superoxide, O 2 Hydroxyl, OH Peroxyl, RO 2 Alkoxyl, RO Hydroperoxyl, HO 2 Reactive nitrogen Radicals Nitrogen oxide, NO Nitrogen dioxide, NO 2 Peroxynitrite, ONOO

There are four types of ROR/RNR damages Damage to fat compounds Attack the fatty membranes surrounding the cells loose its ability to transport oxygen, nutrients or water to the cells. Damage to protein molecules Attack the nucleic acid The nucleic acids function is to regulate the normal cell function, growth and also to repair the damaged tissues. Cell damage Damages done to the chromosomes and nucleic acids The first step in cancer development Lysosomes damages The enzymes leak out when the membrane cell breaks and they start digesting the cell itself Lower the immune system resistance

ROR/RNR redox signaling Stimulating cell growth Programmed cell death Induction of mobilisation of ion transport systems Diseases Inflammation Cardiovascular disease Ageing Neurodegenerative diseases such as Parkinson's disease Alzheimer's disease Cancer Obesity

The free radical theory of aging Cells continuously produce free radicals Constant radical damage eventually kills the cell When radicals kill or damage enough cells in an organism, the organism ages. The production of radical oxygen, the most common radical in biological systems, occurs mostly within the mitochondria of a cell. The primary site of radical oxygen damage is mitochondrial DNA (mtDNA). mtDNA cannot be readily fixed. Extensive mtDNA damage accumulates over time and shuts down mitochondria, causing cells to die and the organism to age.

Some cellular antioxidants enzymes such as Superoxide dismutase, Catalase Glutathione Peroxidase Peroxiredoxins and Sulfiredoxin Small molecule antioxidants such as Ascorbic acid (vitamin-C) play important roles as cellular antioxidant.

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