This document defines and provides examples of various types of active principles found in plants and animals. It discusses alkaloids, glycosides, saponins, fixed oils, volatile oils, fats, waxes, gums, resins, oleoresins, gum resins, balsams, tannins, and neutral principles. For each type, it provides a definition and chemical properties, where they are found, examples of specific active principles, and sometimes uses. The document is intended as a reference for the different classes of active chemical constituents that can be extracted from crude animal and plant materials.

1. Active Principles
Of Drugs &
Pharmacopeias
DR. GHULAM SAQULAIN
M.B.B.S., D.L.O., F.C.P.S
HEAD OF DEPARTMENT OF
ENT
CAPITAL HOSPITAL,
ISLAMABAD

2. Active Principle Definition
The chemical constituents present in crude
animal/vegetable preparations, responsible for
their biological activity are called active principles.

3. Important active principles
 Alkaloids
 Glycosides
 Saponins
 Fixed oils
 Volatile oils
 Fats
 Waxes
Gums
Resins
Oleoresins
Gum resins
Balsams
Tannins
Neutral principles

4. Alkaloids:
Nitrogenous compounds of complex structure.
Found in plants, more than one alkaloids may be present in
one plant.
Intensely bitter.
Insoluble in water, soluble in alcohol.
Very active biologically, alkaline in reaction.
Form salts with acids which are water soluble.
Mostly solids, only a few are liquids.
English names end in ----“INE”.

5. Solid Alkaloids:
Morphine, Papavarine
Atropine , Hyoscine
Quinine
Ephedrine
Strychnine
Liquid Alkaloids:
Nicotine , Pilocarpine , Lobeline

6. Glycosides:
1. Non nitrogenous, containing carbon, hydrogen & oxygen
2. Complex structure & very active biologically
3. Found in plants
4. Hydrolyzed by acid / enzymes into:
• Sugar component or Glycone ----
Mainly determines pharmacokinetics
• Non-Sugar component or Aglycone/Genin - --Pharmacologically active
5. When sugar component is glucose, it is called glucoside
6. English names end in letter “IN”

7. Cardiac Glycosides:
Digoxin
Digitoxin
Gitoxin
Gitalin
Strophanthin

8. Saponins:
These resemble glycosides
Neutral in reaction
Found in plants
Act as emulsifying agents
Form clear solution with water which forms
froths on shaking
They are toxic
May cause haemolysis of RBCS
Examples:
Senegin, Quillia sapotoxin

9. Fixed Oils:
Obtained from various plants or animals.
Esters of higher fatty acid (Oleic/Palmitic/Stearic acids) .
Insoluble in water , soluble in ether, chloroform, alcohol.
Non irritating .
Leave greasy mark on paper.
Decompose on distillation .
Form soaps with alkalies.
Used as: Nutrient , Emollient , Purgative.
Examples: Castor oil , Cod liver oil , Olive oil.

10. Volatile Oils:
(Essential Oils / Ethereal Oil)
Obtained from various parts of plants by distillation processes &
are highly aromatic.
Mostly contain liquid hydrocarbons
In addition most contain oxidised hydrocarbons.
They are usually crystalline solids, called stearoptenes
Highly aromatic, slightly water soluble – impart smell & taste.
Used as:
 Carminative e.g. cardamon oil
 Diuretic e.g. oil of sandal wood
 Antiseptic e.g. clove oil

11. Fats:
Fixed oils solid at room temperature
Natural ester of glycerol & fatty acids. All the three
OH groups of glycerol are esterified, so called
Triglycerides
Examples: Theobroma (cocoabutter)

12. Waxes:
Esters of fatty acids with monohydric alcohols
Complex mixtures
Used in ointments & other topical preparations used on
skin.
Examples: White bee’s wax (cera alba)

13. Gums:
Plant exudations
Carbohydrate in nature
Amorphous, Transparent
Form viscous solution with water – Mucilage
Used as suspending/emulsifying agents in preparation
of suspensions & emulsions.
Examples: Gum Acacia, Gum Tragacanth

14. Resins:
Solid & brittle substances, produced by oxidation of
volatile oils
Form soap with alkali
Soluble in alcohol
Examples: Colophony.
Oleo Resins: Resins dissolved in volatile oils e.g Copaiba
Gum Resins:
◦Combination of gum + resin e.g. Myrrh, Asafetida
◦Used in dentistry

15. Balsams:
Combination of resins with benzoic acid / cinnamic acid or
both.
Examples: Benzoin
Benzoin is used as Tincture Benzoin Co ---- applied on small
superficial wounds & abrasions.

16. Tannins:
Non-Nitrogenous compounds .
Precipitated by metallic salts or alkaloids.
Astringent action on mucosa.
Produce blue inky color with iron.
Some are hydrolyzed to tannic acid.
Neutral Principles:
Do not conform to any special group .
Examples: Santonin, Bitter principles .