1. بسم الله الرحمن الرحيم
PHG 322 Pharmacogonsy II lecture 1 Presented by Assistant Prof. Dr. Ebtesam Alsheddi

2. Office: second flour # 84 Email: ebtesam.saad@yahoo.com Site: faculty.ksu.edu.sa/10252

3. Topics to be covered: (cont.)
1) Plants containing Alkaloids (botanical and chemical characters):
Introduction
Phenylalkylamine, Tropolone and Imidazole alkaloids
Pyridine and piperidine alkaloids
Tropane alkaloids
Quinoline and isoquinoline alkaloids
Opium alkaloids
Indole alkaloids
Carboline, purine, steroidal and terpenoidal alkaloids

4. Topics to be covered: 2) Marine derived drugs:
Biomedical potential of marine natural products
Microalgae as a drug source
Biologically active substances from marine sponges

5. Topics to be covered:
3) Plants containing Glycosides (botanical and chemical characters):
Introduction
Phenolic, cyanogenic and thioglycosides
Coumarins, flavonoidal glycosides and related compounds
Anthracene derivatives
Cardiac glycosides
Saponins

6. Topics to be covered: 4) Toxicological Pharmacognosy:
Poisonous plants
Plants as drugs of abuse
Hepatotoxic plants
Toxic mushrooms
3) Herb-drug interactions

7. Important Book/Thesis:
No.
Book/Thesis
Editor or Author
Date of pub.
Name of Publisher 1
Pharmacognosy 16th edition
Trease and Evans
2009
Saunders
London, New York, … 2
النباتات السامة في المملكة العربية السعودية
عبد الله بن أحمد الأمير
2000
جامعة الملك سعود
كلية العلوم
قسم النبات والأحياء الدقيقة 3
Bioactive Marine
Natural Products
Bhakuni
and Rawat
2005
Anamaya Publishers, New Delhi, India

8. First ½ of semester (Exam + Activity/Quiz)
The assessment tasks during the semester:
Marks
Assessment task
Dr. Rababb
Dr. Ebtesam - 18
First ½ of semester (Exam + Activity/Quiz)
Second ½ of semester 24
Practical 20
Final Exam
100
Total

9. Deviation from Definition
Alkaloids
Definition
Alkaloids, which mean alkali-like substances, are basic nitrogenous compounds of plant or animal origin and generally possessing a marked physiological action on man or animals.
The nitrogen is usually contained in a heterocyclic ring system.
Deviation from Definition
Some alkaloids are not basic e.g. Colchicine, Piperine,
Few alkaloids contain nitrogen in a non-ring system
e.g. Ephedrine, Colchicine. Mescaline
3) Plant origin:
Some alkaloids are derived from bacteria, fungi, insects, frogs, animals.

10. Function of alkaloids in plants
1) Protective function against insects or herbivores
2) They are end products (detoxification)
3) Source for energy and reserve of nitrogen

11. 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

12. Nomenclature Alkaloids terminate with the suffix: (ine)
Their names may be derived from:
Genus name e.g. Atropine from Atropa
Species name e.g. Cocaine from Coca
Common name e.g. Ergotamine from Ergot
Physiological activity e.g. Emetine (emetic)
Discoverer e.g. Pelletierine from Pelletier

13. Prefixes and suffixes I. Prefixes
These are, usually, added to the name of the parent alkaloid and are used to designate related alkaloids, generally present in the same plant.
Examples are:
I. Prefixes
Nor-: designates N-demethylation or N-demethoxylation e.g. Nornicotine
Apo-: designates dehydration e.g. Apomorphine
Iso-, Pseudo-, Neo- and Epi- indicate different types of isomers

14. II. Suffixes
1) –dine: designates isomerism as in case of the Cinchona alkaloids quinine (l) & quinidine (d)
cinchonidine (l) & cinchonine (d)
2) –ine: indicates, in case of ergot alkaloids, a lower pharmacological activity e.g. ergotaminine is less potent than ergotamine

15. Physical properties: Most alkaloids are crystalline solids
1) Condition:
Most alkaloids are crystalline solids
Some are liquids
volatile
non-volatile
e.g. nicotine and coniine
e.g. pilocarpine and hyoscine
2) Colour:
Most alkaloids colourless
Some are coloured:
- colchicine & berberine yellow
- canadine orange

16. Solubility of alkaloids & their salts is important because:
a) They are often administered in solution
b) Differences in solubility between alkaloids & their
salts is used for:
- isolation of alkaloids
- purification from non-alkaloidal substances

17. - lobeline hydrochloride → CHCl3 (soluble)
Solvent
Alkaloidal bases
Alkaloidal salts
Alcohol
Soluble
Soluble
Soluble
except:
Insoluble
except:
Organic
solvents
- morphine & psychotrine
→ insol. in ether
- lobeline hydrochloride
→ CHCl3 (soluble)
- theobromine &
theophylline
→ benzene (insol.)
Insoluble
except:
H2O
Soluble
except:
quinine sulphate
→ insoluble in H2O
- caffeine
- ephedrine
- codeine
- colchicine
- pilocarpine
- quat. ammonium bases

18. Optically active isomers may show different physiological activities.
4) Optical activity:
Many alkaloids are optically active due to ?
→ presence of one or more asymmetric carbon atom(s)
Optically active isomers may show different physiological activities.
l-ephedrine is 3.5 times more active than d-ephedrine.
l-ergotamine is 3-4 times more active than d-ergotamine.
d- Tubocurarine is more active than the corresponding l- form.
Quinine (l-form) is antimalarial and its d- isomer quinidine is antiarrythmic.
The racemic (optically inactive) dl-atropine is physiologically active.

19. Chemical properties: Alkaloids contain: C, H, N
Most of them contain oxygen
Few alkaloids are oxygen free
nicotine
coniine

20. Chemical Properties: Primary amines R-NH2 e.g. Norephedrine
I- Nitrogen:
Primary amines R-NH e.g. Norephedrine
Secondary amines R2-NH e.g. Ephedrine
Tertiary amines R3-N e.g. Atropine
Quaternary ammonium salts R4-N e.g d-Tubocurarine
II- Basicity:
R2-NH > R-NH2 > R3-N
Saturated hexacyclic amines is more basic than aromatic amines.

21. 1) Nitrogen in alkaloids
Basicity
Number of
nitrogen atoms
Type of amino
group
1) Number of nitrogen atoms:
Usually one N atom
Some contain more than one
→ up to 5 N atoms
e.g. nicotine → two
ergotamine → five 21

22. Quaternary ammonium ion
2) Type of amino group:
N in alkaloids → in form of amine
Primary amino group
Secondary amino group
Tertiary amino group
Quaternary ammonium ion
e.g.
Norpseudo-ephedrine
Ephedrine
Nicotine
Tubocurarine

23. 3) Basicity:
A lone pair of electrons on N atom → basic character
→ alkaloids resemble NH3 in chemical characters
→ form salts with acids without liberation of H2O ] [
Alkaloid
+ H+Cl-
Alkaloid hydrochloride 23 ] [
Present as:

24. Factors influencing the degree of basicity:
Structure of the molecule
Presence & position of other substituents & fuctional groups
e.g. degree of unsaturation
of heterocyclic ring
Pyridine
Piperidine
Electron
withdrawing gps
Electron
releasing groups
e.g.
carbonyl group
e.g.
alkyl group
Piperidine alkaloids →
more basic than pyridine alkaloids
increase basicity
decrease basicity
unsaturation decreases basicity

25. → Alkaloids may be: Neutral (not basic) Ricinine
→ electron availability on
nitrogen atom decreases
Amphoteric
→ due to the presence of acidic group(s)
e.g. alkaloids containing
carboxylic group
e.g. phenolic alkaloids
Narceine
Morphine