Chemical nature of Crude drugs

Objectives On completion of this period, you would be able to know: Various types of active chemical constituents present in crude drugs Carbohydrates

Chemical Nature of Crude Drugs The medicinal properties of crude drugs due to one or more chemical constituents present in them Numerous chemicals present in crude drugs

Chemical Nature of Crude Drugs Very limited number of such chemical constituents exert Pharmacological action known as Active Chemical constituents Others are therapeutically inert Some of them used as Pharmaceutical aids, Technical products

Chemical Nature of Crude Drugs The process by which these complex chemical are formed in the plants by enzymes is known as Biosynthesis The Phytoconstituents in any plant may be same class or mixture of different types

Chemical Nature of Crude Drugs Plant drugs composed of several tissues like Cells, Fibres, Vessels etc., The cell wall may be composed of Cellulose, Lignin, Suberin, Tannins etc.,

Chemical Nature of Crude Drugs The various types of Chemical constituents present in the Crude drugs are Carbohydrates Glycosides Tannins Oils, fats and waxes Volatile oils Resins and their combinations Alkaloids

Carbohydrates These are plant products having Carbon Hydrogen Oxygen In which hydrogen and oxygen are in the same proportion as in water carbohydrates can be correctly defined

Carbohydrates Definition: Polyhydroxy aldehydes or ketones or the compounds which on hydrolysis yield any of the above They may be classified into Mono and Oligo saccharides or simple saccharides Polysaccharides Derived carbohydrates

Mono and oligo saccharides Monosaccharides are crystalline Soluble in water The main functional group of these sugars can be C H O aldehyde C – Carbon H – Hydrogen C = O ketone O – Oxygen Monosaccharides are insoluble in organic solvents Optically active

Simplesaccharides They are further classified into Monosaccharides : Do not undergo further hydrolysis Pentoses Xylose Hexoses Glucose, Galactose Disaccharides : Yield 2 monosaccharides on hydrolysis Maltose Glucose + Glucose Lactose Glucose + Galactose Sucrose Glucose + Fructose Trisaccharides : Yield 3 monosaccharides on hydrolysis Raffinose Glucose + Fructose + Galactose Gentianose Glucose + Glucose + Galactose

Polysaccharides: Polysaccharides are polymers of Monosaccharides When hydrolysed they yield indefinite number of Monosaccharide units. Examples are Starch, Cellulose and Inulin They are insoluble in water With iodine solution give characteristic colour

Derived carbohydrates Gums are Polyuronides consisting of Sugar and Uronic acid units They are amorphous Transperant

Derived carbohydrates Gums are abnormal or pathological products They formed after injury & unfavourable conditions of growth Gums are produced in plants due to degenerative changes in cell walls known as Gummosis

Hydrolysis of gums yield sugars like Arbinose, Galactose, Rhmnose Glucose Xylose Mannose Sugar acids like Glucuronic acid Galacturonic acid

Gums The solution of gums can be precipitated by Lead sub acetate solution, with alcohol. They are used as Binding agents Emulsifying and Suspending agents Thickening agents

Mucilages Neutral or acidic Mixture of both types Mucilages are normal or physiological products Produced without injury to the plants

Isapgol and Linseed are mucilage containing drugs They may be present in epidermis Mucilages are used as Suspending agents Pectins are chiefly or partially Methoxylated PolyGalacturonic acids

Pectins Present in the inner portion of the rind of Citrus fruits and Apples. After absorption of Water Pectins swell up and Form stiff jelly like mass.

Summary In this class we learnt about What are Carbohydrates? Classify carbohydrates with suitable examples

Quiz One of the following does it contain alkaloids a) Digitalis b) Cinchona c) Kurchi d) Rauwolfia

Quiz Identify the homopolysaccaharide a. Pectin b. Oxidase c. Heparin d. Cellulose

Frequently Asked Questions Write different types of Carbohydrates and explain them?