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Ascorbic Acid - [Vitamin C]. Presentor Shweta Bhatnagar San Jose City College. Contents of the presentation. History of Vitamin C Discovery Isolation Sources Natural Vitamin C in plants Chemistry of Vitamin C Molecular Structure Chemical properties Synthesis.
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Ascorbic Acid - [Vitamin C] Presentor Shweta Bhatnagar San Jose City College
Contents of the presentation • History of Vitamin C • Discovery • Isolation • Sources • Natural Vitamin C in plants • Chemistry of Vitamin C • Molecular Structure • Chemical properties • Synthesis
Contents of the presentation • Importance of Vitamin C • Medicinal Uses • Deficiency (Scurvy) • Daily requirements • Metabolism • Conclusion • Q & A
1900’s Scurvy’s initial investigation! 1917Scurvy – Vitamin-C deficiency recognized 1927-28Research continued on! 1933Structure elucidated, Ascorbic Acid was born History of Ascorbic Acid • Discovery 1800’s Cause of Scurvy ?? Also, in the same Year, Hexuronic Acid was found to be Vitamin C
History of Ascorbic Acid • Isolation • Charles king & associates, University of Pittsburgh, PA • 1st April 1932 experimentally proven Vitamin C cured Scurvy • HexuronicAcid isolated from supra-renal glands was VitaminC • Svirbely & Szent - Gyorgyi, University of Szeged, Hungary • 16th April 1932 experimentally proven Vitamin C cured Scurvy • Hexuronic Acid isolated from adrenal cortex, cabbages, oranges etc, was a reducing agent
Sources of Ascorbic Acid • Natural sources • Citrus fruits – Oranges, Lemon • Cabbages • Tomatoes • Supplementary sources • Various dietary supplements – commercially available • Juices rich in Vitamin C
Ascorbic Acid in Plants • Plants synthesize ascorbic acid from • D-Glucose • D-Galactose • D-Glucuronolactone • D-Galacturonic Acid • Metabolism in plants is more complex than observed in Animals because of formation of Tartaric Acid & 2 Carbon fragments with Oxalic Acid. • It is involved in cellular respiration, carbohydrate bio-synthesis & plant growth
CH2OH 6 5 HCOH O 4 1 O H 2 3 HO OH Chemistry of Ascorbic Acid • Molecular Structure It is made from L-Ascorbic Acid which has 3 stereo isomers which are: 1) D-Ascorbic Acid 2) D-Iso Ascorbic Acid 3) L-Iso Ascorbic Acid
Chemistry of Ascorbic Acid • Chemical Properties • Ascorbic acid in aqueous solution is a strong reducing agent • It can be oxidized to dehydro-ascorbic acid (Vitamin C) • It also exhibits enol properties
Chemistry of Ascorbic Acid • Synthesis • Ascorbic Acid are synthesized from C5 Sugars like L-Xylosone, L-Lyxose, L-Xylose, L-Arabinos • Also synthesized from Combination of C2 & C4 carbon units • D-Glucose : It’s most common starting material
Chemistry of Ascorbic Acid • Industrial preparation
Importance of Ascorbic Acid • Medicinal Uses • Enhances wound healing & improves recovery time in surgeries • Help reduce the severity of symptoms of cold & winter illnesses • Plays important role in artherosclerosis & CV diseases • Helps increase immunity for patients suffering from Cancer • Helps maintain integrity of the eye following alkali eye burn • Improves resistance in Asthmatic patients
Other benefits of Ascorbic Acid • Acts as an antioxidant • Maintains Oral health • Normal growth & development • Vitamin C helps control Stress • Important role in aging process • Integral part of various cosmetics specially, age defying • Food preservative
Importance of Ascorbic Acid • Deficiency disease – Scurvy • Early Signs of Scurvy • Weakness • Lassitude • Swelling in legs & arms • Softening of the gums • Hemorrhage from nose, gums & under the skin • Extensive degeneration of bones & cartilage • High susceptibility to infections • In extreme cases it can be ‘fatal’ due to acute infections
Importance of Ascorbic Acid • Daily Requirements • 500mg to 1000mg of Vitamin C/Day helps in normal growth & development of the body • It can be obtained by including lots of fruits & fresh vegetables in daily regular diet
Metabolism of Ascorbic Acid • Absorption of Vitamin C occurs in the intestine through a sodium dependent active transport system • Transport of Vitamin C into the ileum is a carrier mediated process at low mucosal concentrations of Vitamin C • Extra cellular ascorbic acid is oxidized to De-Hydro ascorbic acid (Vitamin C) before being transported to cells • De-Hydro ascorbic acid is reduced to ascorbic acid which is non transportable and remains in the cell • Plasma ascorbic acid level of healthy person is 8-14mg/l
Conclusion • It influences the personality & immune competence • It has reducing/anti-oxidant functions • Aids inner human body environment in warding off adverse external attacks like smoking, pollution, drugs, cancer & so on.
Future Development • Extensive research is going on for better understanding of the vital role of Vitamin C in curing infertility, delayed onset of AIDS symptoms & inhibition of gastric/cervical cancers