Phytochemical Screening Revision Lab PDF

Phytochemical screening Extracts A) Acidic Extract Test for Flavonoids B) Aqueous Extract Test for: 1) Carbohydrates and/or glycosides 2) Tannins 3) Saponins C) Alcoholic Extract Test for: 1) Cardiac glycosides 2) Alkaloids...

Phytochemical screening Extracts A) Acidic Extract Test for Flavonoids B) Aqueous Extract Test for: 1) Carbohydrates and/or glycosides 2) Tannins 3) Saponins C) Alcoholic Extract Test for: 1) Cardiac glycosides 2) Alkaloids 3) Anthraquinones 4) Sterols & triterpenes  A- Acidic extract Test for flavonoids Test Blank 2ml extract + 2ml extract + 2ml 10% NaOH 2ml H2O  Test Blank If Yellow color ;Then, Flavonoids are present  B- Aqueous extract 1)Molisch's test --- for carbohydrates/glycosides 5 dps alcoholic α-naphthol Shake Add 2-3 ml conc H2SO4 dropwise 2ml extract on the walls of t.t  Violet ring at junction Then , carbohydrates and/or glycosides are present  Aqueous extract 2) FeCl3 test for tannins Test Blank Blank 2ml extract + 2ml extract + 2ml H2O + 4-5 dps Fecl3 4-5 dps H2O 4-5 dps Fecl3 Bluish black (hydrolysable tannins) or olive green color (condensed tannins) Then, Tannins are present  Aqueous extract 3) Froth test for saponins: Volumetric Persistant froth (+ ve Saponins) Shake Non-Volumetric but Persistant froth Vigorously (Traces Saponins) 6 ml extract No Froth (-ve Saponins)  After 5 min (+ ve Saponins) (Traces Saponins) C- ALCOHOLIC EXTRACT Step 1: Is the extraction using 70% alcohol 2 spatulas Plant powder Close with cotton for 15 min 30 ml 70% alcohol C- ALCOHOLIC EXTRACT Step 2: Filtration on cotton  C- ALCOHOLIC EXTRACT 1)Buljet’s test ------- for cardiac glycosides Add equal amount Filter on f.p. Of Na2HPO4 5ml lead acetate + 5ml extract If turbid, refilter on f.p Filterate must be clear and If coloured, repeat the whole colourless process Cont. Buljet’s test for cardiac glycosides Test Blank 2ml Filterate + 2ml Baljet’s + 2ml Baljet’s 2ml H2O Leave for 20 min  Test Blank Orange color darker than blank (Then, cardiac glycosides are present) N.B. If light orange (Then, traces of cardiac glycosides) C) Alcoholic extract 2) Dragendorff’sTest for alkaloids Step 1: Add the alcoholic extract to porcelain dish C) Alcoholic extract 2) Dragendorff’sTest for alkaloids Step 2: Put the porcelain dish to dry  C) Alcoholic extract 2) Dragendorff’sTest for alkaloids 3 spots of extract T B 3 spots after 1st evaporation Extract 3 spots after 2nd evaporation T B After f.p. dries, spray only test spots with Dragendorrf’s reagent N.B. If light orange (Then, traces of alkaloids)  Alcoholic extract 3) Borntrager’s test for anthraquinones: Shake Well 2 ml chloroformic extract + 2 ml conc ammonia Rose- Rose red- Red color in the aqueous layer  Alcoholic extract 4) Salkowski's test for Sterols & triterpenes: 1-2 ml conc H2SO4 dropwise on the walls of t.t 2 ml chloroformic extract Reddish brown ring at the junction between 2 layers