SOME INFO ABOUT SOME MEDICINAL NATURAL PRODUCT

1. CHEMISTRY OF NATURAL
PRODUCTS
COLCHICINE, OUABAIN

2. OUTLINE
1.Natural source
2.Chemical structure
3.Medicinal use
4.Mechanism of action
5.Chemical nature
6.Pharmaceutical preparation
7.Derivatives and analogues
8.Side effects
9.Specific chemical test

3. Colchicine

4. NATURAL SOURCE
Extracted from plants Colchicum also known as “meadow
saffron”

5. CHEMICAL STRUCTURE
C22H25NO6

6. MEDICINAL USE
• A highly toxic plant hormone that is used in the treatment of gout
• Antimitotic agent as it stops the process of cell division.
• It also has an anti inflammatory effect by its ability to bind with
tubulin.
• Is also used to prevent attacks of pain in the abdomen, chest, or
joints caused familial Mediterranean fever.

7. MECHANISM OF ACTION
• Colchicine inhibits microtubule polymerization by binding to
tubulin so colchicine effectively functions as a “mitotic poison”

8. MECHANISM OF ACTION
• Colchicine inhibits microtubule polymerization by binding to
tubulin so colchicine effectively functions as a “mitotic poison”
• Also inhibits neutrophil motility and activity, leading to an anti-
inflammatory effect. This has proven useful in the treatment of
acute gout flares.

9. CHEMICAL NATURE
Alkaloid: odourless or nearly odourless, pale yellow
needles or powder that darkens on exposure to light

10. PHARMACEUTICAL PREPARATION
Compounding powder, intravenous solution, oral capsule,
oral tablet

11. DERIVATIVES AND ANALOGUES
Colchicine

12. SIDE EFFECT
• Side effects include gastrointestinal upset and neutropenia.
• High doses can also damage bone marrow, lead to anaemia, and
cause hair loss.
• A main side effect associated with all mitotic inhibitors is peripheral
neuropathy, which is a numbness or tingling in the hands and feet
due to peripheral nerve damage.

13. SPECIFIC CHEMICAL TEST
1. Colchicine + 60-70% H2SO4 or HCl Yellow color
2. Alc. Soln. of Colchicine + FeCl3 Red color

14. Ouabain

15. NATURAL SOURCE
Found in the roots, stems, leaves, and seeds of the:
Acokanthera schimperi Strophanthus gratus

16. CHEMICAL STRUCTURE
C29H44O12

17. MEDICINAL USE
• Treat hypotension and cardiac arrhythmia.
• Treatment of heart failure, angina pectoris and
myocardial infarction despite its poor and variable
absorption.
• Recently, use as a contraceptive that it can severely
decrease the motility of spermatozoa

18. MECHANISM OF ACTION
• Inhibit Na+/K+-ATPase. leads to increase intracellular sodium
which reduces the activity of the sodium-calcium pump which
pumps 1 calcium ion out the cell and 3 sodium ions into the cell
down concentration gradient.
• This elevates intracellular calcium. Which results in higher
cardiac contractility and an increase in cardiac vagal tone.
• The change in ionic gradients caused by ouabain can also affect
the membrane voltage of the cell and result in cardiac
arrhythmia.

19. CHEMICAL NATURE
Glycoside: odourless, white crystals or crystalline powder,
extremely bitter taste

20. PHARMACEUTICAL PREPARATION

21. DERIVATIVES AND ANALOGUES
• p-nitrophenyltriazene ouabain (NPT-ouabain)
• aryldiazonium ouabain (AD-ouabain).

22. DRUG INTERACTION

23. SPECIFIC CHEMICAL TEST
1. Ouabain + mixture of conc.H2SO4 and water
Brownish red color
2. Froehde’s test : Ouabain + froehde’s reagent, evaporate
to dryness, cool then add drop of H2SO4 Blue color
3. Mandelin’s test : moisten few drops of crystals then add
mandelin reagent evaporate to dryness, cool then add
conc. H2SO4 Green color

24. QUESTIONS
• What is the chemical nature of colchicine ?
• What is the mechanism of action of Ouabain ?

25. Thank
you