Glycosides and Their Types

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Questions and Answers

What is the result of shaking the yellowish ethereal layer with dilute ammonium hydroxide?

A pink to violet color in the aqueous layer (correct)

A bright yellow color in the aqueous layer

A deep blue color in the ethereal layer

No observable color change

Which of the following best describes the flavonoid group?

A series of C6-C3-C5 compounds

A combination of C6-C3-C6 compounds (correct)

A series of C5-C3-C5 compounds

A combination of C5-C2-C5 compounds

Which of the following is NOT a recognized use of flavone glycosides?

Serve as a food preservative (correct)

Improve cerebral circulation

Act as antioxidants

Reduce capillary fragility

What color do flavonoids typically exhibit when dissolved in alkalies?

Yellow Signup and view all the answers

Cyanogenic glycosides release which compound upon hydrolysis?

Hydrocyanic acid Signup and view all the answers

Which test is used to identify the presence of cardiac glycosides?

Liebermann’s test Signup and view all the answers

What are the characteristics of saponin glycosides?

They cause haemolysis of red blood cells. Signup and view all the answers

Which type of saponins are notably important for their relationship with sex hormones and cortisone?

Steroidal type Signup and view all the answers

What type of compounds do alkaloids generally form when reacting with acids?

Alkaloidal salts Signup and view all the answers

Which reagent produces a creamy precipitate for the identification of alkaloids?

Mayer’s reagent Signup and view all the answers

Which of the following drugs contains steroidal saponins?

Ginseng Signup and view all the answers

Which of the following properties is true regarding most alkaloids?

They form salts when combined with acids. Signup and view all the answers

What is the primary usage of Quillaia root?

Emulsifying agent Signup and view all the answers

What is a common characteristic of a glycoside?

It can be hydrolyzed into an aglycone and sugar. Signup and view all the answers

Which type of glycoside is characterized by having a single sugar unit?

Monoglycoside Signup and view all the answers

Which linkage is the most common in glycosides?

O-glycosidic linkage Signup and view all the answers

What is true about glycosides and Fehling’s solution?

They do not reduce Fehling’s solution except after hydrolysis. Signup and view all the answers

What component does NOT play a role in the classification of glycosides?

Physical state of the glycoside Signup and view all the answers

Which of the following is an example of an S-glycoside?

Sinigrin Signup and view all the answers

Which term describes a glycoside with three sugar units?

Triglycoside Signup and view all the answers

How are glycosides classified based on their chemical nature?

Primary, secondary, tertiary Signup and view all the answers

What distinguishes primary glycosides from secondary glycosides?

Primary glycosides occur naturally in fresh plants, while secondary result from hydrolysis. Signup and view all the answers

Which of the following is a characteristic of phenolic glycosides?

Arbutin is an example and acts as a skin lightening agent. Signup and view all the answers

What is the function of anthracene glycosides when tested with alkali?

They produce a red or purple color. Signup and view all the answers

Which of the following glycosides are categorized under cyanogenic glycosides?

Sinigrin Signup and view all the answers

What is the main active constituent of Uva ursi leaves?

Arbutin Signup and view all the answers

What is a common use for anthracene glycosides?

As a laxative or purgative. Signup and view all the answers

Which group of glycosides includes steroidal components?

Saponin glycosides Signup and view all the answers

What best describes the process of hydrolysis in glycosides?

The breakdown of glycosides into simpler carbohydrates. Signup and view all the answers

Which characteristic is associated with picric acid solution?

It gives yellow precipitates. Signup and view all the answers

Which statement is true regarding volatile oils?

They should be stored in cool, dry conditions. Signup and view all the answers

Condensed tannins are also known as:

Catechol tannins. Signup and view all the answers

What happens to hydrolysable tannins when treated with acids or enzymes?

They can be hydrolyzed by acids or enzymes. Signup and view all the answers

Which application is NOT a use of volatile oils?

Leather production. Signup and view all the answers

What identifies condensed tannins in their reaction with ferric chloride?

They turn green. Signup and view all the answers

What is a primary component of volatile oils?

Terpene hydrocarbons. Signup and view all the answers

Which of the following statements is true about tannins?

They prevent animal hides from decaying. Signup and view all the answers

Study Notes

Glycosides

Glycosides are organic molecules of plant origin composed of a sugar portion (glycone) linked to a non-sugar part (aglycone) via a glycosidic bond.
The sugar portion is typically glucose, making the glycoside a glucoside.
Glycosides can be hydrolyzed into aglycone and sugar(s) by acids or enzymes, with emulsin being a common hydrolyzing enzyme.
Glycosides are classified by:
- Number of sugar molecules (monoglycosides, diglycosides, etc.)
- Linkage between sugar and aglycone (O-glycosides, C-glycosides, S-glycosides)
- Nature of the glycosides (primary, secondary, tertiary)
- Chemical nature of the aglycone

Types of Glycosides

Phenolic Glycosides:
- Contain phenolic groups, exemplified by arbutin.
- Arbutin, the main active constituent of Uva ursi leaves, serves as a diuretic, antiseptic, and skin lightening agent (hydrolyzes to hydroquinone).
Anthracene Glycosides/Anthraquinone Glycosides:
- Contain anthracene derivatives as aglycones.
- Produce a red or purple color when alkali is added to powdered drugs containing anthraquinone derivatives (anthracene screening).
- Examples include sennosides A, B, C, and D from Senna leaf and cascarosides from cascara bark.
- Used as cathartics, purgatives, and laxatives.
Flavone Glycosides:
- C6-C3-C6 compounds often found in yellow plants that dissolve in alkalies to give yellow solutions.
- Examples include diosmin from Buchu leaf and hesperidin & rutin from citrus.
- Uses include reducing capillary fragility (diosmin and rutin), antioxidant activity (green tea), and improving cerebral circulation (ginkgo biloba).
Cyanogenic (Cyanophore) Glycosides:
- Yield hydrocyanic acid upon hydrolysis.
- Examples include digitoxin, squill, and strophanthus.
Steroidal/Cardiac Glycosides:
- Contain a steroidal nucleus, often indicated with Liebermann's test (reddish ring at the junction of acetic anhydride and concentrated sulfuric acid layers).
Saponin Glycosides:
- Possess foaming properties in aqueous solution and cause haemolysis of red blood cells.
- Aglycones are referred to as sapogenins.
- Divided into:
  - Steroidal type: related to sex hormones, cortisone, vitamin D, and cardiac glycosides; used as starting materials for synthesis of these compounds. Examples include fenugreek and ginseng.
  - Triterpenoidal type: Examples include quillaia, licorice, and senega. Quillaia is used as an emulsifying agent, and senega is used as an expectorant in chronic bronchitis.

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Description

This quiz covers the fundamental aspects of glycosides, including their structure, hydrolysis, and classification. Explore different types of glycosides like phenolic and anthracene glycosides, and learn about their unique properties and applications. Test your knowledge on these important organic molecules and their roles in plants.