2. OBJECTIVES
To know what are the characteristics of
alkaloids
To know the different sources of alkaloids
To determine the importance of alkaloids and to
identify their applications in pharmacy
To know the different test in determining the
presence of alkaloids
3. WHAT ARE ALKALOIDS?
These are commonly applied to basic
nitrogenous compounds of plant origin that are
physiologically active.
Organic nitrogenous compounds with a limited
distribution in native nature.
5. CHARACTERISTICS:
They are bitter in taste.
Derived from amino acids
Alkaloids form double salts with compounds of
mercury, gold, platinum and other heavy
metals. These salts are obtained as precipitate
which are microcrystallographic.
6. Most but not all alkaloids possess basic
properties owing to the presence of
amino nitrogen.
Structurally complex end products of
energy- requiring reaction sequences.
7. Alkaloids usually contain one nitrogen atom
but some may contain 5 nitrogen atoms such
as ergotamine. The nitrogen may exist as a
primary amine (RNH2), secondary amine
(R2NH), tertiary amine (RN), or as
quaternary.
8. PROPERTIES OF ALKALOIDS
Insoluble or sparingly soluble in water, but
the salts formed on reaction with acids are
usually freely soluble.
Most are crystalline solids although a few are
amorphous.
9. Free alkaloids are usually soluble in ether,
chloroform, or other relatively non-polar
immiscible solvents.
Some alkaloids are liquid because of
lacking of oxygen in their molecules. (e.g
coniine, nicotine, spartenine)
10. The degree of basicity varies greatly,
depending on the structure of the
molecule and the presence and location of
other functional groups.
Have high melting points
11. SOURCES AND OCCURRENCE OF ALKALOIDS
Alkaloids can occur in plant kingdoms;
among the angiosperms, the Leguminosae,
Papaveraceae, Ranunculaceae, Rubiaceae,
Solanaceae, and Berberidaceae are
outstanding alkaloid-yielding plants.
12. The Labiatae and Rosaceae are almost free of
alkaloids; the gymnosperms only rarely contain
them (Taxaceae).
Specific alkaloids are confined to specific plant
families such as hyoscyamine in Solanaceae,
colchicine in Liliaceae
13. Although it has been claimed that the
monocotyledons do not generally produce
alkaloids, investigations indicate that the
Amaryllidaceae and Liliaceae are two of the
most promising families (of a list 11) in which
to search for alkaloid- yielding plants.
14. Occur in fungi (e.g ergot from Claviceps
purpurea)
Occur in various parts of the plant; in seeds
(physostigma, areca), underground stems
(sanguinaria), roots (belladonna root),
rhizomes and roots (ipecac, hydrastis), barks
(cinchona).
15. USES OF ALKALOIDS IN PLANTS:
Poisonous agents which protect plants
against insects and herbivores
End products of detoxification reactions
representing a metabolic locking-up of
compounds otherwise harmful to the plants.
16. For regulatory growth factors
Reserve substance capable of supplying
nitrogen or other elements necessary to
the plant’s economy
17. PHARMACOLOGIC ACTION OF ALKALOIDS:
Analgesic (morphine, codeine)
Narcotics (strychnine, brucine which are
central stimulant)
Mydriatics (atropine)
Miotics (physostigmine, pilocarpine)
Ephedrine (rises in blood pressure)
Reserpine (produce fall in excessive
hypertension)
19. The biosynthesis of many alkaloidal structures
can be rationalized through simple chemical
reactions that involve amino acids.
The amino acids that are most often serve as
alkaloidal precursors are: phenylalanine,
tyrosine, tryptophan, histidine, anthranilic acid,
lysine and ornithine.
20. 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.
21. TEST FOR ALKALOIDS
Wagner’s Test
(+) Reddish brown precipitate
Reagent used: Wagner’s Reagent [Solution of
iodine in potassium iodide]
Mayer’s Test
(+) Cream color precipitates
Reagent used: Mayer’s Reagent [Potassium
mercuric iodide solution]
22. Dragendorff’s test
(+) Orange precipitate
Reagent used: Dragendorff’s reagent
[Potassium bismuth iodide solution]
Hager's test
(+) Yellow color precipitate
Reagent used: Hager's reagent [saturated
solution of Picric acid]
23. Tannic acid test
(+)buff color precipitate
Reagent used: 10% Tannic acid solution
Valser’s Test
(+) white precipitate
Reagent used: Valser’s reagent (Mercuric
Iodide TS
24. NAMING FOR ALKALOIDS
From the generic name or the genus of the
plant yielding them (e.g hydrastine, atropine)
The specific name or species of the plant
yielding alkaloids ( e.g cocaine,
belladonnine)
Common name of the drug yielding them (e.g
ergotamine)
25. From their physiologic activity (e.g
emetine, morphine)
From the discoverer (e.g pelletierine)
~ All names of alkaloids should end in “-ine”.
~ A prefix or suffix is added to the name of a
principal alkaloid from the same source.
(quinine, quinidine, hydroquinine)
27. PYRIDINE- PIPERIDINE COMBINED
Also referred to as Pyrrolizidine alkaloids
Upon reduction, the tertiary base, pyridine, is
converted into the secondary base,
piperidine.
28. 3 Subgroups
Derivatives of piperidine
Derivatives of nicotinic acid
Derivatives of both pyridine and pyrrolidine
29. Important alkaloidal drugs and alkaloids that are
classified in this group are:
Areca
Arecoline
Hydrobromide
Lobelia
Lobeline
Nicotine
30. NICOTINE
A primarily product of
root metabolism, but the
formation of small
amounts, as well as
subsequent reactions
such as demethylation of
nicotine, can occur in
leaves of plants.
31. It is a pyridine alkaloid obtained from the
dried leaves of the tobacco plant Nicotiana
tabacum Linné (Fam. Solanaceae)
Nicotiana – was named after Jean Nicot
who introduced tobacco in Europe
32. Tabacum – refers to the Indian name for the
pipe or tube used in smoking it
It is colorless to pale yellow, very
hygroscopic, oily, volatile liquid with
unpleasant, pungent odor and a sharp,
burning, persistent taste.
33. USES:
It is bound to an ion exchange resin in a
chewing gum base as a temporary aid to the
cigarette smoker seeking to give up smoking.
Chronic use of nicotine may result in
psychological and physical dependence.
34. ARECA
Areca nut or Betel
Nut
A dried, ripe seed of
Areca catechu (Fam.
Palmae)
Areca- a Spanish and
Portuguese term for
betel nut
35. Catechu- East Indian name for an astringent
extract or juice
Areca mixed with lime, the leaves of Piper bette
Linné and occasionally gambir is known as
“PUNSUPARI”. This mixture is used as a
stimulant masticatory.
Consists of 0.45% alkaloids, 15% tannins,
lipids, volatile oils and gum.
37. Constituents: These are reduced pyridine
derivatives.
Arecoline (arecaidine methyl ester) <most
abundant and physiologically active>
Arecaidine (N-methyl guvacine)
Guvacine (Tetrahydronicotinic acid)
Guvacoline (Guvacine methyl ester)
38. LOBELIA
Indian tobacco
Consists of dried leaves
and tops of Lobelia
inflata Linné (Fam.
Lobeliaceae)
Lobelia – named in
honour of a Flemish
botanist Matthias de L’
Obel
39. Inflata – refers to a hollow and distended
fruit
Substitute for tobacco
Uses:
• Similar but weaker pharmacological effects
in nicotine on the peripheral circulation,
neuromuscular junctions, and CNS.
• Anti-smoking preparations
40. Lobeline sulfate incorporated in tablets or
lozenges are smoking deterrents.
Lobeline had placebo effect on decreasing the
physical craving for cigarettes.
Traditionally used by the Native Americans for
asthma
Chronic bronchitis
Injection of lobeline hydrochloride is used in the
resuscitation of newborn infants
41. Constituents:
Contains 14 alkaloids which
LOBELINE is the major and most important.
It has a pungent, volatile oil, resin, lipids, and
gum.
Lobeline, (-) – lobeline or alpha lobeline
This occurs as colorless crystals which are
slightly soluble in water but readily soluble in hot
alcohol.
42. TROPANE ALKALOIDS
A dicyclic compound formed by the condensation of a
pyrrolidine precursor (ornithine) with three acetate-
derived carbon atoms. Both pyrrolidine and piperidine
ring system can be discerned in the molecule.
The 3-hydroxy derivative of tropane is known as
tropine. Its esterification with (-)- tropic acid yields
hyoscamine (tropine, tropate), which may be
racemized to form atropine.
43. Important alkaloidal drugs and alkaloids that
are classified in this group are:
Belladonna leaf
Hyoscyamus
Stramonium
Atropine
Hyoscyamine
Scopolamine
Coca
Cocaine
44. BELLADONNA
Belladonna leaf,
Belladonna herb or
deadly nightshade leaf
Consists of dried leaf and
flowering or fruiting top of
Atropa belladonna Linné or
of its variety acuminata
Royle ex Lindley (Fam.
Solanaceae)
45. Atropa – is from Atropos meaning inflexible
Belladonna – from Italian word “bella”
meaning beautiful and “donna” meaning
lady
Uses:
It acts as an antimuscarinic agent which
accounts for its use as a spasmolytic drug.
Treating diarrhea, diverticulitis , pancreatitis
46. Used as a adjunctive therapy in the treatment
of peptic ulcer; functional digestive disorders
It possesses anticholinergic properties and is
used to control excess motor activity of the GI
tract and spasm of the urinary tract.
It is commonly administered in the tincture
(3mg alkaloids/ 100ml) or the extract (1.25 g
alkaloids/100g)
48. SOLANACEOUS ALKALOIDS
The principal alkaloids of this group are:
(-) hyoscyamine
atropine [(±) – hyoscyamine]
scopolamine (also known as hyoscine)
49. These are tropine derivatives and esters and may be
prepared synthetically but are usually obtained by
extraction from plants of the Solanaceae such as:
Atropa belladonna
Datura stramonium
Hyoscyamus niger
Hyoscyamus muticus (also known as Henbane)
Dubosia plants
50. Atropine
An antidote in case of poisoning caused by
cholinesterase inhibitors.
It is a CNS stimulant.
51. Scopolamine
It has a depressant activity on the CNS.
It is used to treat motion sickness.
It is employed for preanesthetic sedation
and for obstetric amnesia in conjunction
with analgesics and to calm delirium.
52. Toxicity symptoms occur in using atropine,
scopolamine and belladonna tincture
include:
Skin rash
Skin flushing
Mouth dryness
Difficulty in urination
Eye pain
Blurred vision
Light sensitivity
53. Hyoscyamine
a tropine ester of (-)-tropic acid
Hyoscyamine sulfate
extremely poisonous
It occurs as white, odourless crystals or as
crystalline powder.
It is a deliquescent and is affected of light.
54. It is an anticholinergic and used as an aid
in the control of gastric secretion, visual
spasm, hypermotility in spastic colitis,
pylorospasm and abdominal cramps.
In Parkinsonism, it is used to reduce
rigidity and tremors and to control
associated sialorrhea and hyperhidrosis.
55. Atropine sulfate
It occurs as colorless crystals or as a white,
crystalline powder.
It is extremely poisonous.
It effloresces in dry air and is slowly affected
by light.
It is an anticholinergic, used in surgery as an
antisialogogue.
56. Scopolamine or hyoscine
An alkaloid abundant in Datura fastuosa var.
alba and in D. Metel.
It is an ester that, upon hydrolysis, yields
tropic acid and scopoline.
It occurs as an almost colorless, syrupy liquid
from its chloroformic solution and colorless
crystals from its ether solution.
LEVOROTATORY
57. Scopolamine hydrobromide or hyoscine
hydrobromide
It occurs as colorless or white crystals or as a
white, granular powder that is odourless and
slightly efflorescent in dry air. It is extremely
poisonous.
It is classified as anticholinergic.
It is employed for preanesthetic sedation and for
obstetric amnesia in conjunction with analgesics
and to calm delirium. It is administered SC or IM in
58. Hyoscyamus
Also known as Henbane
dried leaf with or without the stem and
flowering or fruiting crop of Hyoscyamus
niger Linné (Fam. Solanaceae)
It contains not less than 0.04% alkaloids of
hyoscyamus.
59. Hyoscyamus (a Greek and Latin name
formed from two Greek words, meaning
hog and bean.
The plant is poisonous to swine.
The alkaloids, hyoscyamine and
scopolamine, 0.05% to 0.15% of which
three fourths is hyoscyamine are the active
ingredients.
61. STRAMONIUM
Also known as Jimson
weed, Jamestown
weed
dried leaf with or
without the stem and
flowering or fruiting
crop of Datura
stramonium Linné
(Fam. Solanaceae)
62. It yields not less than 0.25% of alkaloids.
Datura (from Sanskrit dhatura, and from
Arabic tatura or tatula, the native name)
Stramonium (from the French word
stramoine meaning stinkweed)
It was used as a “pot herb”
It can serves as atropine
63. STRAMONIUM SEED
from D. stramonium
The seed contains
0.4% of alkaloids,
principally
hyoscyamine with a
small portion of
scopolamine and
traces of atropine.
64. It is generally regarded as a noxious weed
and has frequently caused poisoning in
children when seeds were ingested.
The chief toxic symptoms are those of
atropine:
Dilated pupils
Impaired visions
Dryness of the skin
Secretions
Extreme thirst
Hallucination
Loss of consciousness
65. COCAINE
Coca leaves or Coca
Dried leaves of
Erythroxylum coca
Lamarck which is
commercially known as
“Huanuco coca” or of E.
truxillense Rusby “Truxillo
coca” (Fam.
Erythroxylaceae)
66. Erythroxylum (is from the two Greek words
meaning red and wood)
Coca ( is the Spanish name for the tree)
Truxillense (from Truxillo a coastal city in
Peru)
Contains three basic types of alkaloids:
Derivatives of ecgonine
Derivatives of tropine
Derivatives of hygrine
67. Huanuco coca
Contains 0.5 to 1% of ester alkaloids,
derivatives of tropine and ecgonine
Cuscohygrine is the principal nonester
alkaloid in the leaf.
68. Truxillo coca
Has lower content of ester alkaloids but
higher percentage of cocaine (75%)
The shrub was known as “The Divine Plant
of the Incas”
69. Cocaine hydrochloride
Colorless crystals or as a white, crystalline
powder.
Ingredient in Brompton’s cocktail
Use to control severe pain
CNS stimulant
Administered IV or SC while cocaine free-
based is smoked
70. Crack
extremely addictive smokable forms of
cocaine processed from cocaine
hydrochloride
Its name refers to the sound made when
rocks of cocaine are smoked.
71. QUINOLINE ALKALOIDS
These are alkaloids which contain quinoline as their
nucleus including those obtained from cinchona
(quinine, quinidine, cinchonine, and cinchonidine)
Cinchona and its alkaloids are the only members of
this group that are therapeutically important at
present. Cinchonine, is isomeric with cinchonidine
which is the parent alkaloid of the quinine series.
Quinine and its isomer, quinidine, represent 6-
methoxycinchonine.
73. Cinchona bark or Peruvian bark
dried bark of the stem or of the root of Cinchona
succirubra Pavon et Klotzch or its hybrids,
known in commerce as red cinchona or of C.
ledgeriana (Howard) Moens et Trimen, C.
calisaya Weddell, or hybrids of these with other
species of Cinchona, known in commerce as
calisaya bark or yellow cinchona (Fam.
Rubiaceae)
74. Cinchona (named in honor of the
Countess of Chinchon, wife of viceroy of
Peru)
Succirubra (Latin word meaning red
juice)
Calisaya (a tree)
Ledgeriana ( named in honor of Charles
Ledger)
75. Cinchona toxicity results in temporary loss of
hearing and in impaired sight. Ringing in the
ears is one of the symptoms of toxicity.
When these symptoms are produced as the
result of continuous use of cinchona or of
quinine. The condition has been called
cinchoism.
Cinchona was formerly given in doses of 1g.
76. CUPREA BARK
obtained from Remijia purdieana Triana and R.
Pedunculata Fluckiger (Fam.Rubiaceae)
it has a copper red color hard , compact, and
heavy it contains numerous transversely
elongated stone cells and 2-6 % of alkaloids of
which 1/3 maybe quinine it’s a commercial
source of quinidine.
77. CINCHONA ALKALOIDS
Quinidine
It’s a stereoisomer of quinine and is present
in cinchona barks to the extent of 0.25-
1.25%.
It depresses myocardial excitability,
conduction velocity and to a lesser extent,
contractility.
78. Use to treat various cardiac arrhythmias
such as mature atrial , AV junctional, and
ventricular contractions : atrial flutter and
atrial fibrilations.
When administered orally, the peak serum
levels are slightly lower with the gluconate
and poylgalacturonate salt than with sulfate
salt .
79. The usual real dose available is 10 to 20
mg/kg/day in 4 to 6 divided doses in order to
obtain the average therapeutic serum levels of 3 to
6mcg/ml.
A toxic reaction occurs at levels above 8mcg/ml.
The patient should be instructed to notify the
physician if skin rash,fever,unusual
bleeding/bruising,ringing in the ears,or visual
disturbance occurs.
80. Quinidine sulfate
sulfate of an alkaloid obtain from cinchona
from Remijia pedunculata or prepared from
quinine.
It occurs as fine needle like white crystals that
frequently cohere in masses.
It is odorless , has a bitter taste and darkens
when exposed to light.
It is readily soluble in water, alcohol, methanol
and chloroform.
81. Quinidine gluconate
It occurs as a white powder odorless and has
a bitter taste available in sustained release
tablet.
82. Quinidine polygalacturonate
It affords control and more uniforms
absorptions through the intestinal mucosa
than does quinidine sulfate.
In addition it produces a lower incidence of
GI irritation
83. Quinine
Diastereoisomer of quinidine
It occurs as white, odourless, bulky crystals
or as a crystalline powder.
It darkens when exposed to light and
effloresces in dry air.
It is freely soluble in alcohol, ether and
chloroform but slightly soluble in water.
84. Quinine Sulfate
a sulfate of an alkaloid obtained from the
bark of Cinchona species.
A white, odourless, bitter, fine, needlelike
crystals that are usually lusterless.
It becomes brownish when exposed to light.
It is not readily soluble in water, alcohol,
chloroform or ether.
85. Uses
Antimalarial
For treating of chloroquinine resistant falciparum
malaria combination with pyrimethamine and
sulfadoxine or tetracycline or clindamycin.
It has a skeletal muscle relaxant effect.
It is widely used for the prevention and treatment of
nocturnal recumbency leg cramps.
