1. Alkaloids
Name: SIDIK HASSAN 皇帝
Student No.:911703817007

2. 1.Introduction
2.Classifications
3.Properties of alkaloids
4.Applications
5. Extraction
Contents

3. 1.Introduction
• The term alkaloid is applied to nitrogen
containing molecules belonging to one of the
largest and most diverse families of naturally
occurring compounds. The nitrogen usually is
part of heterocyclic system. These compounds
are grouped together by the presence of
nitrogen atom in their structure

4. 1.Introduction
• The term alkaloid was coined in 1819 by
the pharmacist W. Meisner and meant
simply, alkali like (Middle English alcaly,
from Medeval Latin alkali, from Arabic
alqaliy = ashes of stalwart, from qualey, to
fry). Alkaloid derives from the word
alkaline which means a water soluble base

5. 1.Introduction
• The present of alkaloids is detected
either by precipitants or colour reagents.
• The more important precipitant are
Mayer, Wagner, Dragendorff and Hager.
• The color reagents mostly consist of
dehydrating, oxidizing or a combination
of two.

6. 1.Introduction

7. 1.Introduction
Distribution in Plant:
All Parts e.g. Datura.
Barks e.g. Cinchona
Seeds e.g. Nux vomica
Roots e.g. Aconite
Fruits e.g. Black pepper
Leaves e.g. Tobacco
Latex e.g. Opium

8. 1.Introduction
2.Classifications
3.Properties of alkaloids
4.Applications
5. Extraction
Contents

9. 2.Classifications of alkaloids
• Alkaloids are often divided into the
following major groups:
1. True alkaloids
2. pseudo alkaloids
3. Proto alkaloids
4. False alkaloids

10. 2.Classifications of alkaloids
• Many classification systems are possible for
alkaloids
• Due to variety of sources
• Basic chemical structure, Pharmacological
action

11. 2.Classifications of alkaloids
1. Tropane
2. Quinoline
3. Isoquinoline
4. Indole
5. purine

12. 2.Classifications of alkaloids
6. Pyrrole & Pyrrolidine Nicotine
7. Pyridine & Piperidine Ricinine
8.Phenanthrene Morphine
9. Imidazole Pilocarpine
10.Steroidal Connesine

13. 1.Introduction
2.Classifications
3.Properties of alkaloids
4.Applications
5. Extraction
Contents

14. 3.Properties of alkaloids
3.1 physical properties
I. condition
Most alkaloids are crystalline
solids.
Few alkaloids are amorphous
solids e.g. emetine.
Some are liquids that are either:
Volatile e.g. nicotine and coniine,
or
Non-volatile e.g. pilocarpine and
hyoscine

15. 3.Properties of alkaloids
II- Color:
The majority of alkaloids are colorless but
some are colored e.g.:
Colchicine and berberine are yellow.
Canadine is orange.
The salts of sanguinarine are copper-red.

16. 3. Properties of alkaloid
• III- Solubility:
• Both alkaloidal bases and their salts are soluble in alcohol.
• Generally, the bases are soluble in organic solvents and insoluble in water
• Exceptions:
• Bases soluble in water: caffeine, ephedrine, codeine, colchicine, pilocarpine
and quaternary ammonium bases.
• Bases insoluble or sparingly soluble in certain organic solvents: morphine
in ether, theobromine and theophylline in benzene.
• Salts are usually soluble in water and, insoluble or sparingly soluble in
organic solvents.
• Exceptions:
• Salts insoluble in water: quinine monosulphate.
• Salts soluble in organic solvents: lobeline and apoatropine hydrochlorides
are soluble in chloroform

17. 3.Properties of akaloids
3.2 chemical properties
• Most alkaloids contain Oxygen and are solid in
nature e.g. Atropine
• Some alkaloids are free from Oxygen and are
mostly liquids e.g. Nicotine, Coniine.
• Alkaloids are decomposed by heat, except
Strychnine and caffeine (sublimable).
• they react with acids to form salt formation
• Saturated hexacyclic amines is more basic than
aromatic amines.

18. 1.Introduction
2.Classifications of Alkaloids
3.Properties of alkaloids
4.Applications
5.Extraction
Contents

19. 4. Applications
4.1 Functions in plants
• They may act as protective against insects an
herbivores due to their bitterness and toxicity.
• They are, in certain cases, the final products of
detoxification (waste products).
• Source of nitrogen in case of nitrogen deficiency.
• They, sometimes, act as growth regulators in
certain metabolic systems.
• They may be utilized as a source of energy in case
of deficiency in carbon dioxide assimilation.

20. 4. Applications
4.2 in medicine
• Atropine: eyes, heart, secrations
• quinine: treat malaria
• Reserpine: Hypertesion
• caffeine: CNS stimulant
• nicotine: Enhances concentration, learning and
memory.
• Morphine: pain medication

21. 1.Introduction
2.Classifications of Alkaloids
3.Properties of alkaloids
4.Applications
5. Extraction
Contents

22. 5.Extraction
• Because of the structural diversity of alkaloids, there is
no single method of their extraction from natural raw
materials. Most methods exploit the property of most
alkaloids to be soluble in organic solvents but not in
water, and the opposite tendency of their salts.
• Most plants contain several alkaloids. Their mixture is
extracted first and then individual alkaloids are
separated. Plants are thoroughly ground before
extraction. Most alkaloids are present in the raw plants
in the form of salts of organic acids. The extracted
alkaloids may remain salts or change into bases.

23. 5.Extraction
• Base extraction is achieved by processing the raw
material with alkaline solutions and extracting the
alkaloid bases with organic solvents, such as 1,2-
dichloroethane, chloroform, diethyl ether or
benzene. Then, the impurities are dissolved by
weak acids; this converts alkaloid bases into salts
that are washed away with water. If necessary, an
aqueous solution of alkaloid salts is again made
alkaline and treated with an organic solvent. The
process is repeated until the desired purity is
achieved

24. 5.Extraction
• In the acidic extraction, the raw plant material is
processed by a weak acidic solution (e.g., acetic
acid in water, ethanol, or methanol). A base is
then added to convert alkaloids to basic forms that
are extracted with organic solvent (if the
extraction was performed with alcohol, it is
removed first, and the remainder is dissolved in
water). The solution is purified as described
above.
• Alkaloids are separated from their mixture using
their different solubility in certain solvents and
different reactivity with certain reagents or by
distillation.

25. References
• Natural products chemistry sources, seprations
and structures (Raymond Cooper George
Nicola)
• Introduction to natural product chemistry

26. Thank you!