ASCORBIC ACID

© by Nimmervoll Michaela

10.09.2009

Higher secondary school for chemical ingeneering

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INDEX History Properties Biosynthesis Adsorption and metabolic processes Function Determination

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HISTORY Remedy for scorbut 1747: James Lind Ascorbic acid – scorbut 1932: Waugh & King:

Hexuronacid 1933: Harworth & Szent-Györgyi:

Ascorbic acid

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PROPERTIES Withe crystalline substance Molecular weight:

179 g/mol Melting point:

190°C Water dissolves Effectivity:

D-Glucoascorbine acidVitamine A, E, B6, B12, K + Testosterone

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BIOSYNTHESIS Higher plants, most animals by D-

Glucose liver (mammals) kidney (birds, amphibian, reptils)

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ADSORPTION AND METABOLIC PROCESSES

Quickly in whole small intestine Pass cell mebrane (oxidized, lipophilic

form) Reduction to Ascorbic acid With circulation to organs Absorbing capacity: 1000mg

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FUNCTION Biochemical functions:

Hydrogen donator (electrons)Hydrogen acceptor (electrons)

Hold up body-functions:Sore cure and keloidSterotoninbiosynthesisSynthesis of THF and folic acidResistance infectious diseaseFerric resorptionRadical catcher

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DETERMINATION Materials:

Ascorbic acid2.6.-DichlorphenolindophenolOxalic acidChloroform testing tubes

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2.6.-Dichlorphenolindophenol Leuko - 2.6.-Dichlorphenolindophenol

DETERMINATION Implementation

Make 2.6.-Dichlorphenolindophenol (b=0,4 g/l)

Make ascorbic acid standard (b=2,5 g/l)2ml water in testing tube, and

0,5/1/1,5/2/2,5ml ascorbic acid+ small quantity oxalic acid+ 0,1ml 2.6.-DCPIPShake itWait 15 sec.+ 1,5ml chloroformadd step-by-step 2.6.-DCPIP till load transfer

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DETERMINATION

2.6.-DCPIP

blank sample

sample

sample

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SOURCES http://www.lebensmittelwissen.de/

chemie/ascorbinsaeure/eigenchaften-vitamin-c.php

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The EU-Comenius Life-long-learning-program is financially granted by the

European Commission.