Page 115 - phytochemistry I - PharmD Clinical

a basis of classification, all class of natural product will be involved,
example lignan glycosides, alkaloidal glycosides etc. A therapeutic
classification, can also be used.

1. According to the type sugar molecule
Glucosides: the sugar portion is glucose
Rhamnosides: the sugar portion is a rhamnose.
Pentoside: the sugar portion is pentose.
Fructoside: the sugar portion is fructose.
Arabinoside: the sugar portion is arabinose.

2. According to the number of sugar molecules
Monoside: A glycoside containing one sugar molecule.
Bioside: A glycoside containing two sugar molecule.
Trioside: A glycoside containing three sugar molecule.
Tetroside: A glycoside containing four sugar molecule.

3. According to atom involved in the glycosidic linkage
• O-glycosides:

These are glycosides where the sugar part is linked with
an oxygen atom of aglycone. They are common in higher plants
such as Senna and Rhubarb.

• C-glycosides:
These are glycosides where the sugar part is linked with a carbon
atom of aglycone. The sugar is linked (condensed) directly to
carbon atom of aglycone, for example aloin type glycosides
present in aloes. These are characterized by their resistance to
hydrolysis by heating or with dilute acids or alkalis. C-glycosides
can only be hydrolysed by oxidative hydrolysis with ferric
chloride.

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