Page 149 - PG 504-theoretical notes-phyto-1-2024-2025..

Clinical pharmacy PharmD program Third level Phytochemistry-1 (PG-504)

Amygdalase Prunase
Glucose + Prunasin Glucose + Benzaldehyde + HCN

O CH-CN
Prunase
+
C H O 4 Gentiobiose Benzaldehyde + HCN
6
10
O
Emulsin or
C H O 2 Glucose + Benzaldehyde + HCN
6 11 5 Acid

Amygdalin
Detection of Cyanogenetic Glycosides:

Cyanogenetic glycosides can be detect in plant materials by Guignard , s test in which:

The plant material is crushed, moisten with warm water, then HCN is produced as a result of
hydrolysis of the glycoside can be detected by its reaction with sodium picrate to form sodium
isopurpurate, which has a brick-red.

Sulfur Containing Glycosides (Thioglycosides)

Ex.: Sinigrin

They are s-glycosides widely distributed in family Cruciferae.

Sinigrin: glycosides occurring in seeds of black mustard.

Sinalbin: glycosides occurring in white mustard seeds.

Hydrolysis of them, yields genins of thiocyanate structure (mustard oils).

Uses: rubefacients and counter irritants

The following is the general structure of thioglycosides

S Glucose
+
R C X Thioglycosides
N OSO 3

Sinigrin

Source

The glycosides and their specific enzymes ( myrosins ) are found in different cells in the seeds.
So, they do not interact until they are brought together by the destruction of the cell walls.

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