B.PHARM 3rd SEM PHARMACOGNOSY 1st.

1. #. Alkaloids #.
DEFINE.
Rahul Pals  INVERTIS INSTITUTE OF PHARMACY.  2/17/2020

2.  #. Alkaloids #.
 Page 1
#. Alkaloids #.
DEFINE.
The word “alkaloids” can be divided into two parts:
Alkal  Alkali (base).
Oids  Like.
Therefore, alkaloids are alkali like compounds.
#. Characteristics of Alkaloids:
1) Basic in nature.
2) Certain nitrogen.
3) Heterocyclic in nature (diff. cycle).
4) Derived from Amino Acid.
#. Classification/ Types of Alkaloids.
Category True
Alkaloids
Proto
Alkaloids
Pseudo
Alkaloids
Basic. Present. Present. Present.
Nitrogen. Present. Not
present.
Present.
Heterocyclic. Present. Present. Present.
Derived from
Amino Acid.
Present. Present. Not derived
from Amino
Acid.
#. Physical Properties of Alkaloids
01). Solid Nature:
Maximum alkaloids are solid in nature however, some can
be liquid or gas.
02). Crystalline Nature:
Most of the alkaloids have specific shape & size due to
which they are crystalline in nature.
03). Sharp Melting point & Boiling point:
Alkaloids are crystalline in nature due to which the have
accurate (shape) melting point & boiling point.
04). Solubility:
Alkaloids are insoluble in water but soluble in organic
solvents.
05). Colour:
Maximum alkaloids are colorless in nature kept:
(Barbarine = Yellow colour.)
(Canadine = Orange colour.)
#. Identification of Alkaloids:
Experiment Procedure Result / colour.
Dragendorff’s
Test.
Drug + Dragendorff’s reagent. Orangish red
colour.
Mayer’s Test. Drug + few drops of Mayer’s
reagent.
Creamy-white
precipitate.
Hager’s Test. Drug + few drops of Hager’s
reagent.
Crystalline yellow
precipitate.
Wagner’s Test. Drug + few drops of Wagner’s
reagent.
Reddish-brown
precipitate.
Tannic Acid
Test.
Drug + few drops of tannic
acid solution.
Buff colored
precipitate.

3.  #. Alkaloids #.
 Page 2
#. Glycosides #
DEFINE.
Glycosides are the organic compound which on
hydrolysis produces sugar & non sugar parts.
 The sugar is known as “Glycon” whereas
non sugar parts as known as “Aglycon”
or “Genin”.
 The Glycon & Aglycon part are joined
together with the help of “Glyosidic
bond”/ “Glyosidic linkage”.
#. Classification of Glycoside.
The glycoside is divided into three types:
❑ On the Basis of Glycon.
Based upon sugar present in glycoside
they are named as:
A). Glucoside = Sugar is glucose.
B). Lactoside = Sugar is lactose.
C). Rhamnoside = Sugar is rhamnose.
D). Fructoside = Sugar is fructose.
❑ On the Basis of Aglycon
The Aglycon is responsible for pharmacological/
therapeutic activity. Based on Aglycon, glycoside is
derived into several mainly on tow criteria:
❑ Therapeutic effect.
❑ Atom / group present in Aglycon.
#. On the Basis of Glycosides Linkage/
Glycosidic bond [C-SON]
Glycoside are of four type, based on glycosidic bond:
[01]. C- Glycoside:
When the -OH group of glycone reacts with -CH
group.
Aglycone, water is released & C-Glycosidic is formed.
Types of
Glycosides.
Procedure.
Cardiac glycoside It is used for the treatment of heart
diseases.
Aldehyde glycoside In this the Aglycon part contain
aldehydes.
Phenol glycosides Aglycon parts contains phenol.
Anthraquinone
glycoside
They are used for the treatment of
constipation.
Cyanogenetic
glycoside
Aglycon part contains CN.
Isothiocyanate
glycoside
Aglycon part contains SCN.
Bitter glycoside Aglycone part is bitter in taste.
Saponin glycoside These glycosides have soap like tendency
& forms foam when mixed with water.

4.  #. Alkaloids #.
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Glycon -C- Aglycone
Glycone -OH + HC – Aglycone.
- water
Glycone -C- Aglycone.

C- Glycoside.
[02]. S – Glycoside:
When the -OH group of glycone reacts with -CH
group.
Glycone -OH + HC – Aglycone.
- water
Glycone -S- Aglycone.

S - Glycoside.
[03]. O – Glycoside:
Glycone -OH + HC – Aglycone.
- water
Glycone -O- Aglycone.

O - Glycoside.
❑ They may be solid or liquid in nature.
❑ They are crystalline due to which that have
sharp melting point & boiling point.
❑ They are soluble in water due to presence of
“Glycone” part.
If a drug contains more Aglycone part than it is
soluble in organic solvents.
Glycone part is responsible for absorption of drugs
whereas “Aglycone” part is responsible for
therapeutic / pharmacological activity.
Experiment Procedure Result
Haemolysis
Test.
A drop blood on slide was
mixed with few drops of
aq. Saponin solution.
Presence of Saponin.
Keller kiliani
Test
Drug + Methanol +
Glacial Acetic Acid + fecl3
+ conc. Sulfuric Acid.
Blue colour.
#. Physical Properties
#. Identification Test of Glycosides