Classification of the Glycosides and their Properties

What are Glycosides?

Glycosides are the organic compounds from plants or animal sources which on enzymatic or acid hydrolysis give one or more sugar moieties along with non-sugar moiety.

English: Glycoside (Photo credit: Wikipedia)

The sugar moiety is called as glycone and non sugar moiety is called as aglycone. Aglycone is also called as genin.

Chemical Structure of Digitalis glycosides. (Photo credit: Wikipedia)

According to the chemical nature of the aglycone moiety, they are classified as:

• Anthraquinone or Anthracene glycosides
• Sterols or Cardiac glycosides
• Saponin glycosides
• Cyanogenetic or cyanophoric glycosides
• Isothiocynate glycosides
• Flavanoids or Flavanol glycosides
• Coumarin and Furanocoumarin glycosides
• Aldehyde glycosides
• Phenol glycosides
• Steroidal glycolalkaloids
• Glycosidal bitters or miscellaneous glycosides

Foxgloves produce several deadly chemicals, namely cardiac and steroidal glycosides. Ingestion can cause nausea, vomiting, hallucinations, convulsions, or death. (Photo credit: Wikipedia)

According to the therapeutic activity, glycosides are classified as

• Cathartics
• Cardiotonics
• Analgesics
• Anti-rheumatics
• Anti-ulcers

Glycosides are also classified as per the glycone as

• C-glycosides
• O-glycosides
• S- glycosides
• N- glycosides

Basic Information about Glycosidal Bitters and Miscellaneous Glycosides:

Bitters are the substances which are taken before the meal for improving the appetite. These include various drugs of natural origin. They have the activities like bitter, stomachic, digestive and febrifuge (reducing fever).

These glycosides are not chemically similar and does not belong to the same class. The prominent drugs contain the glycosides of monoterpene irridoids with pyran cyclopentane ring.  Physiologically, the bitters are having stimulant effects on gustatory nerves in the mouth and lead in the increase in gastric juice secretion.

Basic Information on the Isothiocynate Glycosides

Isothiocynate glycosides are also known as glucosinolate compounds. The aglycone part of these glycosides contain isothiocynate, as it contains sulphur along with nitrogen.

These glycosides are widely scattered in a few higher families, the important one of them is Cruciferae. The other families are Resedaceae and Capparidaceae.  Many of the plants belonging to these families contains an enzyme, myrosinase.  These are the glucosides of the isothiocynates.