these are some of the essential test which is employed for glycosides. it is important for students who are 4 semester of b pharma. (pharamacogonosy ) .

1. CHEMICAL TESTS FOR GLYCOSIDES
1. Introduction: Glycosides are natural occurring molecules which carry a sugar group which is
bounded by its anomeric carbon to other group by a glycosidic bond.
Glycosidic bonds have the property of bind a sugar molecule to another molecule. Basically, a
substance which carry a glycosidic bond is known as glycoside.In the structure of glycoside, the
sugar group is known as glycone and the nonsugar group is known as aglycone.
2. Classification:
a. On the basis of glycone:
• Glucoside: If the glucose group is present in glycoside, then it is known as glucoside.
• Fructoside : If fructose group is present in glycoside, then it is called fructoside.
• Glucuronide: If glucuronic acid is present , then it is known as glucuronide.
b. On the basis of aglycone: on the basis of presence of nature of aglycone group classes are
as follows:
• Sterol and triterpenoid glycosides
• Anthraquinone glycosides
• Cyanogenetic and cyanophoric glycosides
• Saponin glycosides
• Flavone glycosides
• Coumarin glycosides
• Steroidal or cardiac glycoside
3. Chemical tests according to classes:
a. Sterol and triterpenoid glycoside:
• General tests :
(1) Antimony trichloride test: An alcoholic extract of drug →evaporate → dry → make extract with
chloroform + saturated solution of antimony trichloride in chloroform containing 20% acetic anhydride
→ appearance of pink colour on heating → presence of steroids and triterpinoids.
(2) Tetranitro methane test : Alcoholic extract of drug + tetranitro methane solution →formation of
yellow colour → presence of .sterol and triterpenoid.
• Specific tests for sterol :
(1) Libermann burchard test : Alcoholic extract of drug → evaporated → dry →extracted with
CHCl3 + few drops of acetic anhydride + conc.sulphuric acid ( from the side wall of test tube) →
appearance of violet ring → blue colour → presence of sterol group in drug.

2. (2) Salkowaski test : Alcoholic extract of drug→evaporated →dry → extracted with CHCl3 + conc.
H2SO4( from side wall of test tube) →appearance of yellow colored ring (at the junction of two
liquids) → turn to red → presence of sterol group in drug
• Specific test for triterpenes :
Trichloro acetic acid test: Drug + saturated trichloro acetic acid → coloured precipitate →
presence of triterpenes .
2. Anthraquinone glycosides :
Specific tests: For c- types of anthraquinone glycosides
(i) Modified borntrager's test : 1 gm of drug sample + 5ml of dilute HCl + 5 ml of ferric chloride
→Boil for 10 min. on water bath → cool (on room temperature) →filter → extract of filtrate with
carbon tetrachloride or benzene + equal amount of ammonia solution →appearance of pink to red
colour → presence of anthraquinone moiety.
(ii) Borntrager’s test :
1gm of drug sample + 5-10 ml of dilute HCl + 10 min. boil on water bath and filter + extract of filtrate
with CCl4 or benzene + equal amount of ammonia solution to filtrate + shake → appearance of pink
to red colour → indicate presence of anthraquinone moiety.
3. Cyanogenetic and cyanophoric glycoside :
• Specific tests for cyanogenetic glycoside:
(i) Cuprocyanate test : Saturate the filter paper in freshly prepared solution of guaiac resin +
dissolved in ethanol → dry . → make contact with that filter paper with dilute solution of CuSO4
→place it with contact of drug sample → Generation of HCN gas with the appearance of stain → the
presence of cynogenetic glycoside.
(ii) Feeriferrocyanide test: 1 gm of drug sample + 5 ml of alcoholic KOH → transfer it to aqueous
solution of FeSO4 and FeCl3 → keep it at room temperature for10 minutes. → transfer the whole
solution to 20 % HCl →appearance of Prussian blue colour → the presence of cynogenetic
glycosides .
(iii) Precipitation of mercury from HgNO3 :Generation of HCN gas by→reduction of aqueous
mercurous nitrite solution → metallic Hg → the presence of cyanogenetic glycosides.
• Specific tests for cynophoric glycosides:
(i)Sodium picrate test : small amount of drug sample → humidification with water in a conical flask
+ few drops of conc. H2SO4 → appearance of brick colour → presence of cynophoric glycoside.
4. Saponin glycosides:
(i) Haemolysis test : A drop of blood on slide + few drops of aq. saponin solution → appearance of
ruptured red blood cells →the presence of saponin glycoside.
(ii) Foam test : 1 gm of sample drug + 10 to 20 ml of water →well shaked →generation of froths →
the presence of saponins.

3. 5. Flavonoid glycosides :
General test:
(i) Shinoda test : alcoholic extract of 1 gm of drug + magnesium turnings dilute HCl → appearance
of red colour → the presence of flavonoids.
• alcoholic extract of 1 gm of drug sample + zinc turning + dil. HCl →appearance of deep red colour
→ turns to magenta colour → the presence of dihydro flavonoids( other type of flavonoid glycoside).
(ii) Ammonia test : To the alcoholic solution of 1 gm of drug sample , when filter paper dipped and
after that exposed to ammonia vapor, appearance of yellow spot on the filter paper indicates the
presence of flavonoid.
(iii) Vanillin HCl test :
Alcoholic solution of drug sample + vanillin HCl → appearance of pink colour→ presence of
flavonoid
6. Coumarin glycoside :
specific tests:
(i) Fluorescence test :
Alcoholic extract of drug sample + NaOH solution (1N) → generation of blue – green fluorescence →
indicates presence of coumarins.
(ii) Ferric chloride test :
Concentrate alcoholic extract of drug sample + few drops of alcoholic FeCl3 solution →appearance
of dark green colour → turned to yellow after some time on addition of conc. HNO3 → indicates the
presence of coumarins.
7. Cardiac glycosides :
Specific test:
(i)3,5-dinitro benzoic acid test :
Alcoholic solution of drug sample + few drops of NaOH + 2 % solution of 3,5- dinitro benzoic acid
→appearance of pink colour → indicates the presence of cardiac glycosides.
General tests :
(i) Legal test :
Alcoholic extract of drug + equal volume of water + 0.5 ml of strong lead acetate solution → well
shake →filter → filtrate extracted with same volume of CHCl3→CHCl3 extract evaporate → dryness
→ remainder dissolve with 2 ml of pyridine and sodium nitroprusside + NaOH solution to make it
alkaline → appearance of pink colour → indicates the presence of aglycon or glycoside moiety.
(ii) Baljet test :

4. Section of drug containing cardiac glycoside ( thick section of leaf of digitalis) →dipped into sodium
picrate solution → appearance of yellow to orange colour → indicate the presence of aglycon moiety.
(iii)Keller – kiliani test :
Alcoholic extract of drug + equal volume of water + 0.5 ml of strong lead acetate solution → shake
→ filter→ filtrate extracted with same amount of CHCl3 → CHCl3 extract evaporated to dry →
remainder dissolved in 3 ml of glacial acetic acid + few drops of FeCl3 solution + 2ml of conc.
H2SO4→ reddish brown layer → turns to bluish green → indicates the presence of aglycon (
digitoxose).