found in both state in free or combination with glycosidic., not all members of the group are phenolic (8).The tannin compounds are phenolic polymers precipitate protein from aqueous solution and it is reduce or inhibit enzyme activity (9).
Objectives of this study are Phytochemicals screening of the green and black tea, which included:(1) Qualitative analysis of Alkaloid, Anthraquiaones, Cardenolides, Tannin, Saponins, Coumarin, Flavonoid, Steroid and Carbohydrates in green and black tea extracted by water, ethanol and petroleum ether in green and black tea extracted by water, ethanol and petroleum ether. (2) Quantative analysis of Alkaloid and Tannin content
2.0 Materials and methods
2.1 Sample preparation: The dried green and black teas were collected from local market of Khartoum State, Sudan., the dried teas (green and black) were freed from foreign materials and ground into fine powder to pass 0.4 mm mesh screen. The prepared samples were kept in tight containers and stored at room temperature until analysis. Preparation of e aqueous extraction of tea (green and black) by using water, ethanol and petroleum ether is carried out according to method described by (10).
2.2 Qualitative analysis: Alkaloid, Saponins, Tannin, Steroid, Flavonoids, Comrine, Cardiac and Carbohydrates were identified according to method described by (10).
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2.2.1 Alkaloid: Two gram of well ground samples was extracted with 10 ml of 1%HCL for 30 minutes in water bath. The suspension was filtrated through cotton whool into tube and the filtrate solution was divided into two portions A and B. Then saturated solution of sodium bicarbonate was added to the filtrate solution (B) till pH become 8 -9 and the solution was mixed with 3 ml chloroform, then upper layer was removed by pipette and treated with acetic acid till pH become 5 and five drops of dragendroff,s regent were added. If the precipitate is form. This indicated the presence of quaternary alkaloid. The lower layer (chloroform) was treated with 3 ml of 1%HCL which separated the lower layer into two layers. Then upper layer was pipette and treated with dragendroff,s regent, this indicated to presence of tertiary alkaloid.
2.2.2 Anthraquinones: 0.5 gram of well ground sample was extracted in boiling water for two minutes with 5 ml 0.5N KOH and 0.5 ml H2O. Suspension was cooled and filtrate by using glass wool and six drops of acetic acid was added, then the solution was mixed with 5 ml benzene, The upper layer was separated and pipette into test tube followed by adding of 2 ml 0.0N KOH. If the solution gives red colour. This indicated the presence of Anthraquinones.
2.2.3 Cardenolides: 3 gram of well ground sample was extracted 2 ml of distil water in boiling water bath for 30 minutes, then allow the solution to cool and filtrate by using glass wool into test tube. 10 drops of lead acetate was added and then filtrate to tube (A) and (B). Four drops of Keddle,s reagent was added The solution (B) was mixed with 2 ml chloroform, and 4 drops of Keddle,s reagent was added to lower layer. If the solution gives a violet colour. This indicated the presence of Cardenolides.
2.2.4 Tannin: 3 gram of well ground sample was extracted with 1 ml distil water in boiling water bath for 5 minutes, then filtrate the solution by using filter paper and allow a solution to cool . The filtration solution was divided into two portions A and B. 5 ml of 2% NaCL was added to portion A. Suspended solution was filtrated by using filter paper, followed by adding 5 ml 1% gelatin solution. Precipitate indicated the presence of Tannin. 1 ml of 1% ferric chloride was added to portion B. The green blue colour indicated the presence of Tannin.
2.2.5 Saponins: 3 gram of well ground sample was extracted with 5 ml distil water in boiling water bath for 6 minutes. Then filtrate the solution by using glass wool. 1 ml of sample extracted was shaken for 5 minutes and finally the persistent and voluminous froth is formed.
2.2.6 Coumarin: 3 gram of well ground sample was extracted with 5 ml distil water in boiling water bath for 6 minutes, then filtrate the solution by using filter paper and allow a solution to cool. Then the sample extracted shows a blue fluorescence, but it changed into greenish – blue on addition of few drops of ammonia. This indicated to presence of coumarin.
2.2.7 Flavonoid: 3 gram of well ground sample was extracted 2 ml of distil water in boiling water bath for 30 minutes, then allow the solution to cool and filtrate by using glass wool into test tube. 10 drops of lead acetate was added to filtration. The yellowish
