Lecture 5 Medicinal Plants PDF

 Primary & secondary metabolites Plant cell produces two types of metabolites:  Primary metabolites  Secondary metabolites = Active constituents 1. Not essential for pl...

 Primary & secondary metabolites Plant cell produces two types of metabolites:  Primary metabolites  Secondary metabolites = Active constituents 1. Not essential for plant life 1. Essential for plant life 2.Not involved in metabolic 2. Involved in metabolic activity. activity, considered as end products of primary metabolism. 3. For normal physiological 3. play a role in the interaction of growth and energy requirements the organism with its environment, of plants and are also utilized ensuring the survival of the as food by man. organism in its ecosystem. 4. (e.g. proteins, 4. (e.g. Phenolics, terpenoids, vitamins, hormones, alkaloids, glycosides, amino acids and fats). antibiotics etc….). 5. Secondary metabolites have many applications (medications, pigments, flavors, cosmetics….)  1. Carbohydrates Carbohydrates are polyhydroxy aldehydes, or ketones or substances that hydrolyze  polyhydroxy aldehydes & ketones. They usually contain H & O in the same ratio as in H2O (2:1). Carbohydrates have the general formula: Cx(H2O)Y where X = Y e.g. hexoses C6(H2O)6 Exceptions: 1- Deoxy sugars ex: Rhamnose C6H12O5  Classification of Carbohydrates according to the number of sugar units Monosaccharides Oligosaccharides Polysacccharides Formed of 1 sugar unit Yield 2 to 10 Yield > 10 cannot be hydrolyzed monosaccharides monosaccharides to simpler carbohydrates on hydrolysis on hydrolysis  Monosaccharides HO H 1 CHO 1 C H OH H OH HO H HO H H OH H OH 5 5 H OH H O 6 CH2OH 6 CH2OH D-Glucose -D-glucose Aldehydic form []D = + 18.7o Ketone form Disaccharides  Classification of Polysaccharides Homopolysaccharides Heteropolysaccharides Polymers of more than one Polymers of a single type of monosaccharide or monosaccharide of monosaccharides + sugar derivatives Starch Cellulose Gums Mucilages Dextrins Agar Algin Dextran Inulin Pectic substances  Homopolysaccharides 1. Starch 2. Inulin CH2OH CH2OH CH2OH CH2OH O 1 4 O 1 4 O O 1 O O n O (n >100) CH2OHO Amylose 2 CH2OH CH2OH CH2OH H2C 1 O 1 4 O 4 O 1 1 CH2OHO O O O O 2 m 6 CH2OH CH2OH CH2 CH2OH CH2OH H2C 1 O 1 4 O 4 O 1 O 1 4 O n 4 O 1 CH2OH O O O O O m m 2 CH2OH Amylopectin (m=20-25) Inulin  Heteropolysaccharides  Natural Hydrocolloids complex of Poly- saccharides or salts of polysaccharides (Ca++ or Mg++).  Used as protective agent after Plant injury. e.g. Gum Acacia and gum Tragacanth.  Purified carbohydrate product obtained from the inner portion of the rind of citrus fruit by dilute acid extraction It is completely soluble in water. Acidic to litmus paper. Pectin is used as: 1- Suspending agent 2-Ingredient in many anti-diarrheal formulas iii-  Constitute coloured pigments of petals of flowers.  Colour change according to pH of the cell sap and range from red- violet to blue. e.g., Karkadeh, rose red petal Red Violet Blue HCl Sod. acetate KOH  B-  Yield HCN upon hydrolysis, e.g. Prunasin in Wild Cherry bark and Amygdalin in Bitter Almond  Tested with Guignard’s reagents. Uses: Rheumatoid arthritis  D- e.g. Digitalis, gives stronger but slower heart beat, in cardiac failure.