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CHAPTER IV
PHYSICAL AND CHEMICAL CHARACTERISTICS
Physical and Chemical Characteristics
AMYGDALIN, a vegetable
extracted from the nut of the apricot by the
method described in the previous section, is
a crystalline powder with the following
characteristics:
1. Chemical Name.
D-rnandelonitrile-beta-gIucoside-6-beta-D-gIucoside
2.
Structural Formula.
3. Condensed Formula.
4. Molecular Weight.
457.42 in anhydrous base.
5. Description.
White, crystalline, inodorous powder with a
pronounced bitter taste.
6. Solubility.
Slightly soluble in cold water, alcohol, and
acetone. Very soluble in hot water, alcohol,
and acetone. Insoluble in either.
Methods of Identification
A. A 0.1% solution of AMYGDALIN in distilled
water, shows on the ultraviolet light
spectrum, a maximum absorption of 268, 262,
and 257 microns and a minimum absorption
between 250 and 253 microns of wave length.
B. A 1 % solution of AMYGDALIN hydrolyzed by
reflux with five ml of concentrated
hydrochloric acid per 100ml of solution, for
one hour, gives the following positive
reactions:
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BENZALDEHYDE:
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To five ml of the hydrolyzed
solution is added two ml of 10%
sodium hydroxide. Upon heating,
there appears a strong odor of
almond which increases upon boiling.
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HYDROCHLORIC ACID:
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To five ml of the hydrolyzed
solution is added one ml of
recently prepared 10% ferrous
sulphate, two ml of 10% sodium
hydroxide, one ml of 10% ferric
chloride and three ml of
hydrochloric acid; heat slowly
until boiling and a blue color
appears and a precipitate of the
same color a few minutes later.
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REDUCING SUGARS: |
To five ml of the hydrolyzed
solution is added two ml of alkaline
solution of cupric tartrate (S.R.)
and is heated to boiling: Almost at
once there appears an abundance of
brick colored precipitate. |
Tests for Purity
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A.
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Point of fusion.
Trihydrated
AMYGDALIN has its point of
fusion between 210° and 218° C.
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B.
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Loss during drying.
Not greater than 12% after being
exposed to 105° C for two hours.
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C.
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Residue upon ignition.
Not greater than 0.2% after
exposure to 600°C for three
hours.
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D.
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Clarity and color of the
solution.
The solution of 1% AMYGDALIN in
distilled water is clear and
colorless.
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E.
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Specific rotation.
A 5% solution of AMYGDALIN in
distilled water is levorotatory
(or negative) between -37° and
42°.
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Absence of free cyanide.
After dissolving 200 mg of
AMYGDALIN in five ml of double
distilled water, add to it one
ml of 10% recently prepared
ferrous sulphate, two ml of 10%
sodium hydroxide, one ml of 10%
ferric chloride and three ml of
diluted hydrochloric acid. When
heated to the boiling point
neither blue color nor blue
precipitate appears.
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G.
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Absence of reducing sugars.
If one ml of alkaline cupric
sulphate is added to a 5%
solution of AMYGDALIN and
brought to a boil, the
characteristic brick colored
precipitate does not appear.
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