Chem 227/ Spring 1996/ Dr. Rusay
Ascorbic Acid/ Vitamin C
Since Ascorbic Acid (Vitamin C) cannot be produced in our body, it is considered a vitamin, i.e. an essential nutrient obtained through the diet. USRDA (recommended daily intake) varies by age from as little as 30 mg/day for infants to 60 mg/day for adults. Pregnant and nursing females and smokers require much higher doses( 70, 95, and 100 mg/day respectively.) Clinical deficiencies, although rare, result in scurvy, a condition that results in weak muscles, swollen and bleeding gums, tooth loss, bleeding under the skin, tiredness, depression, and poorly healing wounds. Inadequate amounts result in behavioral changes, reduced drug metabolism, and reduced immunocompetance, all of which affect behavior and performance. It was also discovered over 20 years ago that infants who died from SIDS (Sudden infant death syndrome) were deficient in Vitamin C.
There are five stages of deficiency:
1. Preliminary: depletion of tissue stores, depressed urinary function.
2. Biochemical: decreased enzyme activity, neglible urinary function .
3. Physiological and Behavioral: loss of appetite, decreased body weight, insomnia, irritableness, adverse changes in MMPI scores (tests used to diagnose psychological states; including self-esteem, sociability and depression), decreased immunological function, and impaired drug metabolism.
4. Clinical: exacerbated non-specific symptoms and appearance of specific deficiencies.
5. Anatomical: tissue pathology which can result in death if left untreated.
Ascorbic acid contributes to many health benefits: healthy bones and teeth, increased iron and selenium absorption, increased collagen synthesis, facilitation of tyrosine and proline metabolism, increased rate of healing (used for postsurgical maintenance of strong scar tissue,) decreased levels of leukemic bleeding, decreased risks of mouth, esophagus and stomach cancer and cataracts. It is claimed to protect the lungs against pollutants and moderates symptoms of the common cold. (Linus Pauling believed in the preventative effects so much that he took daily megadoses .) Greater than 60 mg is associated with higher beneficial HDL cholesterol levels and lower blood pressure. The Washington Post recently reported that liquid Vitamin C infused into the blood stream can improve function of blood vessels in adult diabetics.
Topical Vitamin C is being used in sun protection to counter the effects of free radicals that are formed when the skin is exposed to UVA. The photoprotective effects are associated with UVB as well. Topical Vitamin C protects the skin up to three days after application. It has also been suggested to reverse wrinkling.
It has been demonstrated that an ascorbic acid radical reacts as a radical trap preventing the reaction of other free radicals. "Vitamin E and ascorbate probably act synergistically, that is, Vitamin E acts as primary antioxidant (particularly in biomembranes) and the resulting Vitamin E radical then reacts with ascorbate to regenerate Vitamin E. (6) This leads to the recycling of Vitamin E at the expense of Vitamin C and may account for why Vitamin E deficiency isn't shown.
From the information available, it appears that we should all load up on megadoses of Vitamin C. However, it is not without its share of negative effects: i.e. chronic diarrhea, drynose, nosebleeds, rebound scurvy in infants and mothers taking high doses, vomiting, kidney stones, and urinary tract infections. Large doses of solutions of Vitamin C can cause dizziness or faintness (if by injection), flushing or redness of the skin, headache, increased urination, stomach cramps and side or lower back pain.
Crystalline "hexuronic acid", the original name of ascorbic acid, was first isolated from the adrenal cortex of oxen, from orange juice and from cabbage juice in 1928 by Szent-Gyorgyi. In 1934, 1 kg of L-Ascorbic Acid cost $7000. The cost of 1 kg of L-ascorbic acid in the 1992-1993 Aldrich catalog is $137.80 and bulk USP grade prices from other sources are significantly lower. Synthesizing L-ascorbic acid is much more cost efficient today than in 1934. The literature cites over 20 synthetic schemes, including a 3 step synthesis. The fewer number of synthetic steps, can greatly reduce losses and improve the economic efficiency in manufacture.
Bibliography
1. Aldrich Catalog Handbook of Fine Chemicals. Milwaukee, WI: Aldrich Chemical Company, Inc., 1992.
2. "Ascorbic Acid (vitamin C)(Systemic)." USP DI-Volume II Advice for the Patient: Drug Information in Lay Language, ed.: 14 (1994). Infotrac, Health Index ASAP.
3. "C can be more trouble than it's worth." Tufts University Diet & Nutrition Letter, Dec. 1992: 10.
4. Corey, E.J. and Xue-Min Cheng. The Logic of Chemical Synthesis:
New York: John Wiley and Sons, Inc., 1989.
5. Crawford, T.C.; Crawford, S.C. "Synthesis of L-Ascorbic Acid." Advances in Carbohydrate Chemistry and Biochemistry. 37 (1980). R. Stuart Tipson and Derek Horton (Editors.) New York: Academic Press, 1980.
6. Crawford, Thomas C. "Ascorbic Acid: Chemistry, Metabolism, and Uses." Advances in Chemistry Series. 200 (1980). Tolbert and Seib (Editors.) Washington, DC: American Chemical Society, 1980.
7. Fisher Scientific Group, Inc. Material Safety Data Sheet, Revision Date 12/23/93.
8. Gupta, Nelly Edmondson. "The Latest Word on Vitamins." Woman's Day 27 April 1993.
9. Machlin, Dr. Lawrence J.; Hoffman-LaRouche Inc.
The Mount Sinai School of Medicine Complete Book of Nutrition
New York: St.Martin Press, 1990.
10. Le Flur, Isidore; Richard, Jean Paul; Wolff, Gerard (Rhone-
Poulenc Sante.) "Preparation of ascorbic acid." Pat. Appl. EP 403,351. Chemical Abstracts 114 (1991): 229300t.
11. The Merck Index. Budavari, Susan (editor.) Rahway, NJ: Merck & Co., Inc. 1989.
12. Norman, R.O.C. and Coxon, J.M. Principles of Organic Synthesis. United Kingdom: Blackie Academic and Professional, 1993.
13. Shaw, Anita. "Skin care treatments offer some age-old solutions." Soap-Cosmetics-Chemical Specialities Jan 1996: 72. Infotrac, Health Index ASAP. Online. Information Access Company. 21 Mar, 1996.
14. Taber, Anatolij M.; Melenteva, Tatyana A.; Dorrer, Elena M.; Sokolova, Marina L.; Shvedova, Tatyana A. "Preparation of ascorbic acid." Russ. RU 2,001,913
Chemical Abstracts 123 (1995): 314383c.
15. Weiss, Rick. "Vitamin C infusions to diabetics." Washington Post, 9 Jan 1996.