Pharmacognosy II Week 1

Course Information

• Course Title: Pharmacognosy II
• Course Code: PHG 213
• Week number: 1
• Lecture number: 1
• Lecturer: Dr. Hanan Samir Marzouk
• Fall 2024/2025

References

• Wallis, T.E., "Textbook Of Pharmacognosy"; 15th ed., CBS Publishers & Distributors, New Delhi, Bangalore, India (2005).
• Biren N. Shah & A.K.Seth, "Textbook of pharmacognosy and phytochemistry"; 2nd ed., Elsevier (2014).
• Trease, G.E., and Evans, W.C., "Textbook of Pharmacognosy"; 16th ed., Saunders, Bailliere | Tindall, London (2014).
• Important websites: http://www.nlm.nih.gov/medlineplus/herbalmedicine.html, www.herbs.org, www.botanical.com, www.pharmacopoeia.org.uk, www.usp.org

Development of Fruits

• Fruits develop from the flower ovary after fertilization.
• Parts of a flower include ovules, peduncle, sepal, pericarp, ovary, filament, stamen, style, and stigma.
• Seeds are also part of the fruit.

What is Fruit?

• A fruit is the developed ovary (or ovaries) of a single flower or a whole inflorescence.
• The ovary wall develops into the fruit wall, the pericarp.
• The fruit contains the seed that developed from the fertilized ovule.
• Function of the fruit:
  • Protects and nourishes seeds during development
  • Ensures distribution of seeds when mature

Main Characters of Fruit

• Fruits have two scars: a minute apical scar (remains of the style) and a larger scar at the base (attachment to the stalk of the parent plant).
• Other floral parts may be persistent on the fruit (e.g., stigma of poppy capsule, calyx of lobelia, stylopod of umbelliferous fruits).
• The surface of the fruit may be:
  • Smooth and glabrous (e.g., Capsicum)
  • Glabrous (e.g., Fennel)
  • Hairy (e.g., Anise)
  • Granular (e.g., Citrus fruits)
  • Spiny (e.g., Stramonium)
  • Longitudinal striated (e.g., Cardamom)
  • Transversely striated (e.g., Senna)
  • Ridged (e.g., Umbelliferous fruits)
  • Reticulated (e.g., Black pepper)
  • Wrinkled (e.g., Vanilla)

Types of Fruits

• True Fruit: Formed only from the gynoecium (female part of the flower).
• False Fruit: Formed from parts of the flower other than the gynoecium (e.g., receptacle or stalk).

Classification of Fruits

• Classification is based on:
  • Origin (from united or free carpels)
  • Nature of pericarp (dry, leathery, succulent, hard) and number of seeds
  • Dehiscence or indehiscence of the pericarp. (split to release seeds or remain enclosed).
• Examples of fruit types (using a hierarchical structure):
  • Fruit
    • Simple
      • Succulent (drupe, berry)
      • Dry (dehiscent, indehiscent, schizocarpic)
    • Aggregate
    • Composite

Simple Fruits

• Developed from single ovary.
• Classified based on the nature of the pericarp:
  • Dry fruit (e.g., Poppy, Fennel, Star Anise): pericarp is hard, membranous, or leathery.
  • Succulent fruit (e.g., Coco nut): pericarp or parts are modified into fleshy tissue (sometimes fibrous).

Dry Fruit

• Can be dehiscent, indehiscent, or schizocarpic.
• Dehiscent: Pericarp splits open to release seeds (e.g., follicle, legume, siliqua, capsule).
• Indehiscent: Pericarp does not split open; usually one-seeded (e.g., achene, cypsela, samara, nut).
• Schizocarpic: Pericarp splits into several one-seeded parts called mericarps (e.g., Lomentum, Cremocarp).

Dehiscent Fruits (Examples)

• Follicle, Legume, Siliqua, Capsule (descriptions of each included in the document)

Indehiscent Fruits (Examples)

• Achene, Caryopsis (grain), Cypsela, Samara, Nut (descriptions of each included in the document)

Schizocarpic Fruits (Examples)

• Lomentum, Cremocarp (descriptions of each included in the document)

Succulent Fruits (Examples)

• Berry, Drupe (descriptions of each included in the document)

Aggregate Fruits

• Formed from a group of fruits arranged on a single receptacle.
• Developed from an apocarpous gynoecium (where each free carpel develops a fruit).

Composite Fruits

• Formed from a whole inflorescence
• Includes: strobile, sorosis, syconus

Activity Time

• Identify fruits and their classes. (Images provided, classes need to be identified).

Structure of Fruit – Histology

• Fruit consists of a swollen, modified ovary wall called pericarp.
• The pericarp encloses the fertilized ovules (the seeds) which are arranged on the placenta.
• Pericarp is divided into three regions:
  • Epicarp (outer region)
  • Endocarp (inner region)
  • Mesocarp (middle region)

This quiz covers the initial concepts from the first week of Pharmacognosy II, focusing on the development of fruits from the flower ovary and the essential parts of a flower. Students will explore the definitions of fruits and their significance in pharmacognosy. Prepare to test your understanding of these foundational topics.