PHYTOCHEMICAL SCREENING
Phytochemical screening - is a process of tracing plant constituents. For example you want to found out if a certain plant contains alkaloids (a plant constituent) then, you will be performing a phytochemical screening procedures for alkaloids (in this case mayer's and Wagner's test). There are general plant constituents that can be performed with a standard test. And these are screening for: Alkaloids, Saponin, Glycosides, Flavonoids, Tannins, Phenols, Anthocyanins and Carbohydrates.
REAGENT
Mayer's reagent- is an alkaloidal precipitating reagent used for the detection of alkaloids in natural products. Mayer’s reagent is freshly prepared by dissolving a mixture of mercuric chloride (1.36 g) and of potassium iodide (5.00 g) in water (100.0 ml). Most alkaloids are precipitated from neutral or slightly acidic solution by Mayer’s reagent (potassiomercuric iodide solution) to give a cream coloured precipitate.
Wagner's reagent- An aqueous solution of iodine and potassium iodide; used for microchemical analysis of alkaloids. Also known as Wagner's solution. Wagner's reagent is used to test for alkaloids. To prepare Wagner's reagent; Dissolve 2g of iodine and 6g of KI in 100ml of water.
INDICATOR
Alkaloids- are also sources of antimicrobial agents.
Flavanoids- are phytochemicals that could act as an antimicrobial agent.
Saponins- May serve sa anti-feedants, and to protect the plan against microbes and fungi.
Carbohydrates- Are most abundant class of organic compounds found in living organism. It is also for protection of bacterial cells as bacterial cell wall polysacharides, made up of meurin.
Anthocyanin- is used as a determinant in the pH and pOH of acids and bases.
Tannins- Which are mainly used in tanning or darkening the color of fabrics.
Phenols- are phytochemicals that could act as an antimicrobial agent.
Glycosides- are antidiarrheal and inhibit release of autocoids and prostaglandins.
PLANTS WITH PHYTOCHEMICAL SCREENING
What is blackberry?
Blackberry is a sprawling shrub growing up to 3 meter in height. The stems and leaves bear thorns, although some thorn free cultivars exist. The dark green compound leaves consist of 3 or 5 leaflets. The flowers resemble small roses and are white or light pink coloured. During late summer and autumn the typical blackberries are formed, which purplish-black coloured.Parts used
Blackberry leaves, bark and root can be used to make tea. The blackberries (fruits) are also eaten and used in fruit juice and jams.Phytochemicals
These are typical phytochemicals found in blackberry: blackberry leaves contain tannins, gallotannins, dimeric ellagitannins and flavonoids. blackberries (fruits) are exceptionally rich in phytochemicals mainly, flavonoids, anthocyanins, cyanidin, ellagic acid.Benefits of blackberry
Blackberry leaves are traditionally used for the treatment of burns and scald. Tea from blackberry (leaves, root and bark) is astringent and used against intestinal disorders such as diarrhoea and dysentery. Chewing of fresh blackberry leaves helps to heal bleeding gums and inflammation of the mouth and troat.The anthocyanins in blackberries are responsible for the potential anti-carcinogenic properties. The chemopreventive effects of fresh blackberries is caused by their antioxidant properties. Flavonoids strengthen the blood vessels and capillaries.
