1. What is phytochemical?
Phytochemicals are chemical compounds that occur naturally in plants (phyto means "plant" in Greek). Some are responsible for color and other organoleptic properties, such as the deep purple of blueberries and the smell of garlic. The term is generally used to refer to those chemicals that may have biological significance, for example carotenoids orflavonoids, but are not established as essential nutrients.
2. What is 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 screenig for: Alkaloids Saponin glycosides Cardenolides and Bufadionolides Flavonoids Tannins and Polyphenolic compounds Anthraquinones Cyanogenic glycosides Carbohydrates Fixed oils, Fats, and Volatile oils.-Marian m. elevera.
3. What are the different reagents used in Phytochemical Screening?
Phytochemicals are chemical compounds that occur naturally in plants (phyto means "plant" in Greek). Some are responsible for color and other organoleptic properties, such as the deep purple of blueberries and the smell of garlic. The term is generally used to refer to those chemicals that may have biological significance, for example carotenoids orflavonoids, but are not established as essential nutrients.
2. What is 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 screenig for: Alkaloids Saponin glycosides Cardenolides and Bufadionolides Flavonoids Tannins and Polyphenolic compounds Anthraquinones Cyanogenic glycosides Carbohydrates Fixed oils, Fats, and Volatile oils.-Marian m. elevera.
3. What are the different reagents used in Phytochemical Screening?
4.What are the indicators of the presence of each phytochemical?
SteroidsLibermann – Burchard Reaction: 2 ml extract was mixed with chloroform. To this 1-2 ml acetic anhydride and 2 drops concentrated sulphuric acid were added from the side of test tube. First red, then blue and finally green colour appears.
Lignin-
With alcoholic solution of phloroglucinol and concentrated hydrochloric acid appearance of red colour shows the presence of lignin.
Glycosides- Alcoholic extract when made alkaline, shows blue or greenfluorescence.
Terpenoids - Noller’s test: The substance was warmed with tin and thionyl chloride. Pink coloration indicates the presence of triterpenoids.
Proteins- Appearance of red colour shows the presence of proteins and free amino acids.
Biuret test: Equal volume of 5% solution of sodium hydroxide and 1% copper sulphate were added. Appearance of pink or purple colour indicates the presence of proteins and free amino acids.
Carbohydrates - Appearance of reddish orange precipitate shows the presence of carbohydrates.
Gums and mucilages-About 10ml of various extracts were added separately to 25ml of absolute alcohol with constant stirring and filtered. The precipitate was dried in air and examined for its swelling properties and for the presence of carbohydrates.
Phytoserol- Appearance of bluish green colour shows the presence of phytosterol.
Oils and Fats- Appearance of oil stain on the paper indicates the presence of fixed oil.
Tannins and Phenols- Dilute ferric chloride solution (5%) - violet colour
1% solution of gelatin with 10%NaCl - white precipitate
10% lead acetate solution - white precipitate
Flavanoids-With aqueous solution of sodium hydroxide blue to violet colour (Anthrocyanins), yellow colour (Flavones), yellow to orange (Flavonones).
With concentrated sulphuric acid yellowish orange colour (Anthrocyanins), orange to crimson colour (Flavonones).
Shinoda’s test – the extracts were dissolved in alcohol, to that a piece of magnesium and followed by concentrated hydrochloric acid was added drop wise and heated. Appearance of magenta colour shows the presence of flavonoids.
SteroidsLibermann – Burchard Reaction: 2 ml extract was mixed with chloroform. To this 1-2 ml acetic anhydride and 2 drops concentrated sulphuric acid were added from the side of test tube. First red, then blue and finally green colour appears.
Lignin-
With alcoholic solution of phloroglucinol and concentrated hydrochloric acid appearance of red colour shows the presence of lignin.
Glycosides- Alcoholic extract when made alkaline, shows blue or greenfluorescence.
Terpenoids - Noller’s test: The substance was warmed with tin and thionyl chloride. Pink coloration indicates the presence of triterpenoids.
Proteins- Appearance of red colour shows the presence of proteins and free amino acids.
Biuret test: Equal volume of 5% solution of sodium hydroxide and 1% copper sulphate were added. Appearance of pink or purple colour indicates the presence of proteins and free amino acids.
Carbohydrates - Appearance of reddish orange precipitate shows the presence of carbohydrates.
Gums and mucilages-About 10ml of various extracts were added separately to 25ml of absolute alcohol with constant stirring and filtered. The precipitate was dried in air and examined for its swelling properties and for the presence of carbohydrates.
Phytoserol- Appearance of bluish green colour shows the presence of phytosterol.
Oils and Fats- Appearance of oil stain on the paper indicates the presence of fixed oil.
Tannins and Phenols- Dilute ferric chloride solution (5%) - violet colour
1% solution of gelatin with 10%NaCl - white precipitate
10% lead acetate solution - white precipitate
Flavanoids-With aqueous solution of sodium hydroxide blue to violet colour (Anthrocyanins), yellow colour (Flavones), yellow to orange (Flavonones).
With concentrated sulphuric acid yellowish orange colour (Anthrocyanins), orange to crimson colour (Flavonones).
Shinoda’s test – the extracts were dissolved in alcohol, to that a piece of magnesium and followed by concentrated hydrochloric acid was added drop wise and heated. Appearance of magenta colour shows the presence of flavonoids.
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