Structural elucidation of sucrose

Structural elucidation of sucrose

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  STRUCTURAL ELUCIDATION OFSUCROSE Presented by; M Pharm (Pharmaceutical Chemistry) students Gunturu .Aparna Akshintala. Sree Gayatri Thota. Madhu latha Kamre. Sunil Daram. Sekhar University college of pharmaceutical sciences Department of pharmaceutical chemistry Acharya Nagarjuna University Guntur 1
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   Sucrose isthe commonest sugar known. The most common sources are sugar cane and sugar beets and other sources are maple saps, honey and fruit juices.  The use of sugar is as food in various forms.  The molecular formula is C12H22O11  On hydrolysis with acids or enzymes, sucrose gives equal parts of glucose and fructose; which thus constitute the two monosaccharides units of sucrose.
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   Sucrose neitherreacts with phenylhydrazine nor reduce Fehling’s solution indicating that the carbonyl group of the both monosaccharides involved in linkage.  The glucose linked via its to the of fructose.  Sucrose is hydrolysed by maltase but not by emulsin , thus indicating an alfa-D –glucose unit.  Sucrose is also hydrolysed by an enzyme takainvertase thus indicates the beta-D- fructofuranose unit in sucrose.
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   The identitiesof these products demonstrate that the glucose portion is a pyranoside(1:5 linkage) and that the fructose portion is a furanoside(2:5 linkage)
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  Confirmation of Sucrose The structure of sucrose has been confirmed by several physical and chemical evidences.  Determination of stereochemistry of D-glucoside and D-fructoside linkage is complicated by the fact that both linkages are hydrolyzed at the same time.  The structure of sucrose has been confirmed by X-ray analysis  The X-ray analysis of susrose sodium bromide dihydrate confirmed the stereochecal configuration found chemically ,and also the five membered ring of fructose.
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  Periodic acid method:  Periodate oxidation conforms the structure of sucrose by following reaction.  When sucrose is treated with three moles of periodic acid , one mole of formic acid and one mole of a tetra-aldehydes are formed .   The Latter compound on oxidation with bromine water follwed by acid hydrolysis yields a mixture of glyoxylic , glyceric and hydroxypyruvic acids.