Botany lec 3

Faculty of Pharmacy Pharm D Program

  • Lecture 3: Introduction to Medicinal Plants

  • Date: 15/10/2024

  • Instructors:

    • Prof. Haidy Gad

    • Dr. Mohamed Sedeek

KING KSIU SALMAN INTERNATIONAL UNIVERSITY

  • Lecture Topic: Introduction to Medicinal Plants & Pharmacognosy

  • Focus: Natural products and their biological activity

Natural Products & Their Biological Activity

Secondary Plant Metabolites (Active Constituents)

  • Associated compounds in plants that are biologically active.

  • Examples: Quercetin, Menthol

Natural Products Defined

Primary Metabolites

  • Include amino acids, sugars, and lipids.

  • Essential for normal growth and cellular activities.

Secondary Metabolites

  • Compounds that do not contribute to growth/development but have pharmacological effects.

  • Important in defense against herbivores, pathogens, and for attracting pollinators.

  • Typically have a restricted distribution in certain species or families.

Classes of Secondary Metabolites

  1. Carbohydrates and Related Compounds

  2. Glycosides

  3. Tannins

  4. Alkaloids

  5. Volatile Oils

  6. Waxes

  7. Resins and Similar Substances

  8. Others

1. Carbohydrates & Related Compounds

  • Composed of carbon, hydrogen, and oxygen.

  • Includes sugars, starch, gums, mucilage, and pectin.

  • Primarily found as polysaccharides.

Gums

  • Natural plant hydrocolloids categorized as polysaccharides or salts.

  • Example: Gum Arabic, Gum Acacia.

  • Uses: Emulsifying and suspending agents.

Mucilage

  • Polysaccharides formed of sugar and uronic acid.

  • Forms viscous colloidal solutions; non-adhesive unlike gums.

  • Uses: Bulk laxative for chronic constipation.

    • Types:

      • Neutral mucilage (stains blue)

      • Acidic mucilage (stains red)

Pectin

  • Produced from the inner rind of citrus or apple residues.

  • Mucilagenous and soluble in water.

  • Uses: Suspense in anti-diarrhea formulations.

2. Glycosides

Definition

  • Formed by combining a non-sugar part (aglycone) with a sugar part (glycone).

Classification

  • Types of glycosides: O-glycosides, C-glycosides, S-glycosides, N-glycosides.

Phenolic Glycosides

  • Include Simple Phenolic Glycosides (e.g., Arbutin), Flavonoid Glycosides (e.g., Hesperidin), etc.

3. Tannins

  • Large group of complex substances in plants.

  • Two main types: Hydrolyzable and Condensed Tannins.

Uses

  • Astringents in digestive tract and for skin injuries.

  • Antidote for heavy metals and alkaloids.

  • Leather tanning and ink preparation.

4. Alkaloids

Characteristics

  • Basic nitrogenous compounds with physiological activity.

  • Sources mainly flowering plants; can exist as salts or free bases.

Examples

  • Morphine (analgesic), Caffeine (stimulant), Atropine (anticholinergic).

5. Volatile Oils

Description

  • Mixtures of hydrocarbons and oxygenated derivatives; extracted via distillation.

Uses

  • Flavoring, perfumery, antiseptics, and for treating gastrointestinal ailments.

6. Fixed Oils, Fats, and Waxes

Characteristics

  • Esters of fatty acids with glycerol (fixed oils) or higher monohydric alcohols (waxes).

  • Serve various uses in nutrition, cosmetics, and industry.

7. Resins & Similar Substances

  • Solid amorphous products occurring in many plants.

  • Soluble in alcohol, but not water.

  • Examples include Myrrh and Benzoin.

Summary*

  • Identify natural products for chronic constipation management.

  • Explore volatile oils in aromatherapy applications.

Acknowledgments

  • KING KSIU SALMAN INTERNATIONAL UNIVERSITY

  • Website: www.ksiu.edu.eg | Contact: info@ksiu.edu.eg

  • Campuses: Sahely Road, Obour Street, El Nour District