PHARMACOGNOSY PRACTICAL 3: PLANT MATERIAL SAMPLING, EXTRACTION AND PHYTOCHEMICAL ANALYSIS FROM TEA LEAVES Extraction The powdered air-dried plant material be sequentially extracted with solvents of increasing polarity starting with hexane, dichloromethane, ethyl acetate and methanol for 48 hours after which the extract will be concentrated using a rotary evaporator at 40oC in vacuum. This procedure will be repeated three times for each part of plant and for each of the four solvents. Method: (Aqueous extraction method, solvent extraction method (polar and Non polar solvents) etc. Using hot water the finely grounded powder of tea leaves is extracted by dissolving in hot water with occasional stirring to promote uniform and complete extraction. (YOU ARE REQUIRED TO STUDY AND CITE RECENT PUBLISHED PAPERS AND DISCUSS THE PHYTOCHEMICAL COMPOUNDS THAT ARE FOUND IN TEA LEAVES EXTRACTS Saponins test 1ml of the extract is put in a test tube and then 4ml of tap water is added. The mixture is shaken vigorously and if presence of persisting honey combs form, this will be subjected to confirmatory tests. This involved dissolving 1ml of the extract in anhydride tetrachloride to which 4 drops of concentrated sulphuric acid will be added to the mixture. A blue, green or red color accompanied by a pink ring shows presence of saponins. Identification of Alkaloids Transfer the water extract 10ml in a beaker Add 10% Hydrochloric acid (4ml) to the residue containing the alkaloids as salts of some organic acids. To precipitate the aqueous solution of the salts of the mineral acid containing the alkaloids, add 1ml of 10% ammonia solution then extracted add 1ml of chloroform. Evaporate the chloroform solution to dryness by allowing the sample to stand for some time on the bench for 3 minutes. add 1ml of 2% HCl. Divide the acidic solution containing the alkaloids salt into three test tubes ( 2ml each). Add three (3) drops of Mayer’s reagent into two of the test tubes with one test tube left as a reference. The appearance of an opalescen