This document provides information on alkaloids. It begins by discussing the history of alkaloid use by ancient civilizations. It then defines alkaloids as basic nitrogenous compounds that contain heterocyclic rings and have physiological effects. The document outlines various alkaloid properties including solubility, reactions with acids and bases, and classification based on nitrogen content and ring structure. It also lists common plant sources of alkaloids and their medical and biological functions.

4. HISTORY
 Most notorious poisons in the history
of civilization.
 Used by humanity for thousands of
years.
 The first civilizations to use them
were probably the ancient Sumerians
and Egyptians
 It was called a vegetable alkali.

5. •The name “alkaloid” comes from the Arabic word
for ash “al-qali”.
•Contain nitrogenous base in the nucleus
• Term alkaloid was coined by meissner, a German
pharmacist (1819).
• Derosne (French chemist) isolated Narcotine
(1803).
• Serturner (1803) isolated morphine from opium

6. ???????
NO DEFINITE DEFINITION

7. “Naturally occurring
nitrogenous substance
which is isolated from
plants and reacts like
bases”

8. Konigs (1880):- “Naturally occurring organic bases which contains a Pyridine
ring”.

9. Ladenburg “Alkaloid are natural plant compound that have basic
character and contains at least one nitrogen atom in heterocyclic ring”.

10. MUSCOPYRIDINE

11. “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”.

12. MORPHINE

13. DEVIATION FROM
ABOVE MOST ACCEPTED
DEFINITION:

14. RICININE

16. MUSCURAINE

18. CAFFIENE

19. Complete DEFINATION
 These are the naturally occurring
Basic(alkali) nitrogenous compounds
containing one or more nitrogen in
heterocyclic ring system & sometime
obtained/not obtained from amino acid
as a precursor having marked
physiological action on human and
animals when use in small quantities.

20. a).Ranunculaceae : Aconitine (aconite).
b). Leguminoceae : Physostigmine (physostigma)
.
c).loganiaceae: Strychnine and Brucine (Nux-
vomica).
d).Papavaraceae : Morphine, Codiene, Thebaine
(Opium).
e).Solanaceae : Belladona. Datura, Mandragora
(mandrake)

21. f).berberidaceae ; Berberine (Berberis).
g).Rubiaceae: Quinine and Quinidine (Cinchona).
h). Apocyanaceae : Reserpine (Rauwolfia),
Vincristine and Vinblastine (Vinca).
i). Liliaceae : Veriterine (Veratrum).
j).Clavicipitaceae : Ergotamine and Ergometrine (Ergot).

22. GENERAL
PROPERTIES OF
ALKALOIDS

23. a).Most alkaloids are crystalline solid, but
some are liquid e.g.
Volatile; --Nicotine , Coniine & Spartine.

24. Non-Volatile:- Pilocarpine , Hyoscine

25. b).Majority of alkaloids are colorless but
some are colored, e.g
Colchicine and Berberine are Yellow.
Canadine is Orange.

26. C). SOLUBILITY:- Difference in solubility used as a
base for their isolation and purification from non-
alkaloidal bases.
The following can be mentioned :-
a).Both alkaloidal base and their salts are soluble in
alcohol.
b).Generally bases are soluble in organic solvent and
alkaloidal salts are soluble in water.

27. EXCEPTION :
A).Bases soluble in water:--Caffeine, Codeine, Ephedrine.
B).Bases in-soluble or sparingly soluble in certain organic solvent :-
Morphine in ether(1:5000),
C).Salt insoluble in water :---Quinine sulphate
quinine sulphate is only soluble in water to the extent of 1:1000 ,
although quinine hydrochloride is soluble 1 in less than l part of water
D).Salts soluble in organic solvents :---Lobelline and Apo atropine
HCl are soluble in chloroform.

28. 1).Salt formation :--Due to their basic character alkaloid reacts
with acid to form salt
--strong bases form salt with very weak acid.
--weak bases forms salt with strong acid
-- very weak bases form unstable salts.e.g
caffeine , Narcotine , piperine.

29. 2).Amphoteric Alkaloids :--can form salts with both
acid and alkali.
e. g. phenolic group :- Morphine

30. Carboxylic group:--Narciene (a narcotic alkaloid that
occurs in opium).

31. 3). Effect of heat:
Alkaloids are decomposed by heat, except Strychnine
and caffeine (sublimable).
4). Effect of light and Oxygen:
Decomposed when allowed to stand at a temperature
above 70°C for long time.
 sensitivity varies in degree with different alkaloids.
 Decomposition occur rapidly and easily when an alkaloid is
in solution than when it is in dry form.
 Most tertiary amine alkaloids are easily transformed to the
N-oxides.

32. 5).Reaction with acids:
•Salt formation.
•Dil. acids hydrolyze Ester Alkaloids e.g.
Atropine
•Conc. acids may cause :
Dehydration: Atropine → Apo atropine
Morphine → Apomorphine
Demethoxylation e.g. Codeine

33. 6.Effect of alkalis.
• Weak alkalis liberate most alkaloids from their salts
e.g. NH3
• Strong alkalis: such as aqueous NaOH and KOH form
salts with phenolic alkaloids.
• Hot alkalis: results hydrolysis of ester alkaloids e.g.
atropine, cocaine and physostigmine and cleavage of
lactone ring, if present, to produce the corresponding
acid, e.g. pilocarpine is transformed to pilocarpic acid.

34. 7).BASICITY OF ALKALOIDS :--The basicity of alkaloid
is due to presence of a lone pair of electron on
nitrogen atom.
--the basicity increased if the adjacent group is
electron releasing like alkali .
-- the basicity decreases if the adjacent group is
electron withdrawing like carbonyl and amide
group.
R2-NH > R-NH2 > R3-N

35. According to basicity Alkaloids are
classified into:
a). Weak bases e.g. Caffeine
b). Strong bases e.g. Atropine
c). Amphoteric * Phenolic Alkaloids e.g. Morphine
*Alkaloids with Carboxylic groups e.g. Narceine
d). Neutral alkaloids e.g. Colchicine

36. Different types of amines
present in Alkaloids

37. • Primary amines (R-NH2 ) e.g. Norephedrine

38. •Secondary amines (R2-NH) e.g. Ephedrine

39. •Tertiary amines (R3-N), e.g. Atropine

40. •Quaternary ammonium salts (R4-N ), e.g.
d-Tubocurarine
Note :--Unsaturation decreases the basicity e.g. piperidine is more
basic than pyridine alkaloid.

41. PRECIPITATION REACTION :
1- Mayer's or Valser's reagent ( Potassium mercuric
iodide)
-gives white or yellow color mostly amorphous
precipitates with alkaloids, except the purine bases,
ephedrine, Colchicine and ricinine .
Mercuric chloride -1.36g
Potassium iodide -5.00 g
Water to make-100 ml.

42. 2. Wagner's reagent (Iodine-potassium iodide):- It
produces brown or reddish- brown precipitates with all alkaloids.
Iodine -1.3 g
Potassium iodide -2.0 g
Water to make -100 ml
3.Dragendorff's or Kraut’s reagent ( potassium iodide+
bismuth nitrate):- It produces orange-red precipitate which is usually
amorphous.
Bismuth nitrate 8.0 g
Nitric acid 20.5 g
Potassium iodide 27.2 g
Water to 100 ml
4. Hager's reagent (picric acid):- Gives yellow crystalline
precipitate.

43. 5. Tannic acid solution: (5%w/v) .:--gives buff colored
ppt. which is soluble in dil.acid or ammonia.
6.Ammonium reineckate solution: 2% solution,
produces precipitates with heterocyclic nitrogen
alkaloids, with quaternary and some tertiary amines.

44. A). Van-Urks test: (Para-dimethyl-amino-benzaldehyde +
sulphuric acid)-- (for Ergot alkaloids).-gives Blue colour.
B). Vitali-Morin test:-- test for solanceous alkaloids gives violet
colour when treated with conc. nitric acid and alcoholic KOH.
Mechanism :-- These color tests usually depend upon dehydration or
oxidation of the alkaloid with a resultant characteristic color.
Merits :-- a). very sensitive
b). the intensity of the colour so formed is in linear proportion
to the concentration of the alkaloid

45. 1. As reservoir of nitrogen.
2. As reservoir for protein synthesis
3. Afford plant safety from herbivorous and insects.
4. Might have possible role as growth regulatory factor.
5. Acting as carrier within plants for transportation of acids.

46. 1. Analgesics and narcotics: morphine and codeine.
2. CNS stimulants : caffeine and strychnine.
3. Anticancer: vincristine, vinblastine and taxol.
4. Mydriatics: atropine.
5. Anti-asthmatics : ephedrine.
6. Anti-tussives: codeine, vasaka.
7. Expectorants: lobeline.
8. Anti- hypertensive: reserpine.
9. Smooth muscle relaxants: atropine and papaverine
10. Skeletal muscle relaxants: d- tubocurarine.
11. Anthelmintics: pelletierine and arecoline.
12. Antiparasitics/antimalarials: quinine and emetine.

47. Hegnauer's classification
1)."TRUE-alkaloids", which contain nitrogen in the heterocyclic ring
and originate from amino acids. examples are atropine, nicotine,
morphine, and Quinine.
All the heterocyclic alkaloids are true alkaloids.
The true alkaloids should have following characters:
a) It should be sufficiently toxic.
b) Should have marked physiological activity.
c) should be basic in nature.
d) Nitrogen should be present in a heterocyclic ring.
e) Should be derived from amino acids.
f) Should occur in plant as salt of organic acids.

48. 2. PROTO-Alkaloids:- These are alkaloids which are derived from
amino acid but do not have nitrogen in a heterocyclic ring. They are
also called as “Biological amine”.
Examples include:- mescaline, adrenaline and ephedrine.
3. PSEUDO-Alkaloids:--They do not derived from amino acid but
having nitrogen in heterocyclic ring .
They do not show many of the typical characters of alkaloids , but
give standard qualitative test for alkaloids.
e.g. steroidal alkaloids:-Conessine
Purine bases :-- Caffeiene

49. CHEMICAL CLASSIFICATION:-- According to chemical
structure, two broad division may be recognized:
• Non-heterocyclic alkaloids that are sometimes called
''proto alkaloids' or biological amines.
• Heterocyclic alkaloids that are sub-classified into
different groups according to their ring structure.

51. PYRROLE and
PYRROLIDINE
Hygrine , Stachydrine,
Coca species
PYRROLIZIDINE Echimidine, Senecionine,
Seneciphylline,
Symphitine

52. PYRIDINE and
PIPERIDINE
Nicotine , Coniine ,
Arecoline ,Lobeline ,
Pelletierine
TROPANE Cocaine , atropine ,
Hyoscyamine , Hyoscine

53. QUINOLINE Quinine , quinidine ,
Cinchonine,
Cinchonidine cupreine
ISO-QUINOLINE Morphine , Codeine ,
Berberine , Emetine
,Tubocurarine , Papverine,
Narcotine, Narceine,
Emitine, Cephaeline

54. APORPHINE (reduced
Iso-quinoline and
naphthalene)
Boldine
NORLUPINANE Lupanine , sparteine ,
Cytisine, Laburnine

55. INDOLE or BENZO-
PYRROLE.
Ergotamine , ergometrine,
Physostigmine,
Reserpine, Strychnine ,
Brucine, Vinblastine
strychnine, Vincristine
IMIDAZOLE Pilocarpine, Isopilocarpine,
Pilosine

56. PURINE
(Pyrimidine+imidazole)
Caffeine , Theobromine,
Theophylline
STEROIDAL (cyclo
pentanoperhydrophenan-
threne)
Conessine , Solanidine,
Protoveratrine, Funtumine

57. NON-HETEROCYCLIC :--
1.Ephedrine
2. Colchicine
3.Erythromycin
4.Mescaline
5. Taxol

58. SOME IMPORTANT CRUDE DRUGS
Belladonna
Datura
Aconite
Opium

59. Phenanthrene type - Morphine ,
Codeine NARCOTINE

60. Atropine , Hyoscyamine , Hyoscine , Homatropine.
ATROPINE