i am an M.phil scholar in the field of Neurosciences.

1. BIOSYNTHETIC CLASSIFICATION OF
ALKALOIDS
Presented by : M. Jamal
Email: jamalkhan616@gmail.com

2. Alkaloids
• “Basic nitrogenous compound, contains one or more
nitrogen in heterocyclic ring system having marked
physiological action on human and animals when use in small
quantities””.
Classification of alkaloids
• 1. Chemical classification of alkaloids
• 2. Taxonomical classification of alkaloids
• 3. Pharmacological classification of alkaloids
• 4. Biosynthetic classification of alkaloids

3.  Common amino acid precursors:
 Phenylalanine
 Tyrosine
 Tryptophan
 Histidine
 Anthranilic acid
 Lysine
 Ornithine

4. BIOSYNTHETIC CLASSIFICATION OF
ALKALOIDS
Alkaloids are classified on the basis of biosynthetic
precursors from which these are obtained . These
include
 Ornithine derived alkaloids
 Tryptophan derived alkaloids
 Lysine derived alkaloids
 Phenylalanine derived alkaloids
 Tyrosine derived alkaloids
 Histidine derived alkaloids
 Alkaloids derived from substance other than amino
acids.

5. General reactions for biosynthesis of alkaloids
• Some of the general reactions that are of particular
importance include: decarboxylation (removal of
carboxyl group or carbon dioxide) and transamination
(transfer of an amino group from one molecule to another
without the formation of ammonia) of the amino acids to
yield a corresponding amine or aldehyde.
• These can react to form a Schiff base which, in turn can
react with carbanion in a Mannich-type condensation.

6. Alkaloid formation may require the involvement of only one
molecule of amino acid, or 2 molecules of the same AA, or
less commonly, 2 molecules of different AA or else several
molecules of the same AA.

8. ORNITHINE DERIVED ALKALOIDS
It includes:
 Tropane alkaloids
 Pyrrolidine alkaloids`

9. TROPANE ALKALOIDS
(ATROPINE, HYOCYAMINE, HYOSINE, SCOPOLAMINE)
 B.S: Atropa belladona (deadly nightshade), Datura stramonium( thornapple), Hyosyamus
niger(henbane).
 Family: solanaceae
 Part used: dried leaves and flowering tops
 Uses: 1.Atropine is classified as anti cholinergic drugs.
 Atropine can also be used in SLUDGE syndrome( salivation, lacrimation, urination,
diaphoresis, GIT motility and emesis) caused by organophosphate poisoning.
 Hyoscine is used as antispasmodic.
COCAINE
o B.S: Erythroxylum coca, Erythroxylum novogranatense
o Common name. Coca leaves
o Family: Erythroxylaceae
o Part used: Leaves
o Uses: cocaine is a CNS stimulant.
it is also used as local anesthetic.

10. Biosynthesis of tropane alkaloids

11. TRYPTOPHAN DERIVED ALKALOIDS
 These include
INDOLE ALKALOIDS
QUINOLINE ALKALOIDS

13. Indole alkaloids
Physostigma alkaloids
• Botanical source. Physostigma venonosum
• Common name: calabar bean
• Family : Leguminosae
• Part used: dried ripe seeds
• Main constituents: physostigmine ,
isophysostigmine, physovenine.
• Uses: These are the cholinesterase
inhibitors and used as antidote for atropine
poisoning.
• Also used to treat glaucoma.
Ergot alkaoids
B.S: Claviceps purpurea
Family: Hypocreales
Part used: Dried sclerotium of the fungus
Main constituents: Ergotamine,
Ergometrine, Ergocristine
Uses: Ergotamine is used to treat migraine
and clustur headache.
Ergometrine acts as oxytocic agent
and also used in post-partal haemorrhage.
Vinca alkaloids
B.S: Catharanthus roseus
Common name: periwinkle
Family: Apocynacea
Part used: whole plant
Constituents: Vincristine, Vinblastine
Uses: these alkaloids have anticancer
properties.
Rauwolfia alkaloids
B.S: Rauwolfia serpentina
Common name: indian snakeroot
Family: Apocyanacea
Part used: leaves
Constituents: serpentine, reserpine,
ajmaline, ajmalacine,
Uses: used as antihypertensive and
antiarrhythmic agent.

14. Biosynthesis of Vinca alkaloids

15. Quinoline alkaloids
B.S: Cinchona Succirubra, C. calisaya, C.
officinalis
Common name; Quina
Family: Rubiaceae
Part used: Dried Bark
Constituents: Quinine, quinidine, cinchonine,
cinchonidine.
Uses: Quinine is a classical antimalarial.
Quinidine is used for cardiac arrythmias
and atrial fabrillation.

16. LYSINE DERIVED ALKALOIDS
These include
 Lobelia spp
 pepper spp

17. Lobelia alkaloids
• B.S: Lobelia inflata
• Common name: indian tobacco
• Family: Lobeliaceae
• Part used: dried aerial parts
• Constituents: lobeline, isolobeline,
lobelanine, lobeladine
• Uses: it is used in chronic bronchitis and
spasmodic asthma.
lobeline

18. Pepper alkaloids
• B.S: Piper nigrum
• Common name: black pepper, kali mirch
• Part used: dried , unripe fruit
• Family : Piperaceae
• Constituents: piperine and piperittene
• Uses: piper is used as condiment and for chronic bronchitis.

19. ALKALOIDS DERIVED FROM TYROSINE
 Isoquinoline alkaloids
papaver alkaloids
cephaelis alkaloids

20. Papaver alkaloids
• B.S: Papaver somniferum
• Family: papaveraceae
• Part used: dried milky latex of poppy
capsule.
• constituents: Morphine, codiene,
thebaine, Norcotine, Narciene,
papaverine
• Uses: Morphine is used as analgesic.
codiene is used in cough preparations.
Cephaelis alkaloids
B.S: C.ipecacuanha
Common name: Ipecac
Part used: roots and rhizome
Family: Rubiaceae
Constituents: cephaline, psychotrine,
Emetine,
Uses: ipecacuanha is used as expectorant,
and emetic and in the treatment of
Ameobic dysentry.
Emetine

21. BIOSYNTHESIS OF OPIUM ALKALOIDS:
------- L-Dopa ------ Dopamine
+
3,4 – dipydroxyphenylpyruvic acid
PAPAVERINE ----------------- norlaudanosoline
( ket intermediate)
Reticuline
Saluteridine
Saluteredinol

22. Alkaloids derived from phenylalanine
• EPHEDRINE, PSEUDOEPHEDRINE :-
• B.S –It consists of dried young stem of Ephedra
gerardiana and Ephedra nebrodensis.
• Synonym—Ma-huang).
• Family:- Ephedraceae
• C.C:-- It contains the amino alkaloids :
Ephedrine, nor-ephedrine, n-methyl ephedrine,
pseudo-ephedrine.
• Uses: it is used in Asthma, hay fever, flu, cold
medications.

23. Biosynthesis of Ephedrine

24. HISTIDINE DERIVED ALKALOIDS
These alkaloids include Imidazole alkaloids. e.g Pilocarpine

25. It is used in the treatment of glaucoma and atropine poisoning.

26. Alkaloids obtained from precursors other than Amino Acids
Purine alkaloids
Purines are derivatives of a heterocyclic nucleus consisting of a
six-membered Pyrimidine ring fused to a five-membered
Imidazole ring.
Purines are Psudo alkaloids (Are not derived from amino acids
but have nitrogen in a heterocyclic ring)

27. Purine alkaloids
xanthine
coffeine theobromine theophyilline
 They are all methyl derivatives of xanthine.

28. Theobromine
• B.S. Theobroma cacao
• Family: sterculiaceae
• Part used: seeds
• Uses: Cocoa has nutritive,
stimulant and diuretic
properties.
Theobromine is used as a
diuretic. It has less action on
the central nervous system
than caffeine but is more
diuretic.

29. Caffeine
B.S: Coffee arabica
Family: Rubiaceae
Uses: caffeine is used in
combinations with
antipyretics and
analgesics, cold and flu
medication.
also used as Ingredient
in non-alcoholic
beverages and
“energizing” beverages.

30. END