Medicinal Plants PHG111 Lecture 5 Fall 2024 PDF

Medicinal Plants PHG111 Pharmacognosy I PG 101 Prof. Dr. Mahitab Helmi Dr. Ibrahim Ezzeldin Faculty of Pharmacy  Lecture 5 Chemistry of Crude Drugs Interactive teaching methods and activities: https://www.youtube.com/watch?v=BjXaIkBQCdo By the end of this lectur...

Medicinal Plants PHG111 Pharmacognosy I PG 101 Prof. Dr. Mahitab Helmi Dr. Ibrahim Ezzeldin Faculty of Pharmacy  Lecture 5 Chemistry of Crude Drugs Interactive teaching methods and activities: https://www.youtube.com/watch?v=BjXaIkBQCdo By the end of this lecture students must be able to Classify other 2ry metabolites, its chemical nature, tests & uses  4- Alkaloids Atropine Belladonna Caffeine Tea Morphine Opium  Alkaloids ( Cont.) -Basic organic (alkaloid = alkali like) -Nitrogenous compound - Having marked physiological activity Detection: Alkaloids + Mayer’s reagent (potassium mercuric iodide) white precipitate Alkaloids + Wagner's reagent (iodine/potassium iodide) orange color  5- Glycosides Non-reducing substances Bitter tasted solids. Soluble in water and alcohol. Glycosides Hydrolysis By acids or enzymes Aglycone Glycone (sugar) (non-reducing character) (reducing character)  Glycosides A-Phenolic B-Cardiac C-Saponin glycosides glycosides glycosides D-Cyanogenic glycosides E-Thiolglycosides (glucosinolates) (Cyanophore glycosides)  a- Phenolic glycosides 1- Flavonoid glycosides e.g. Boldo, Citrus  It gives yellow color with alkali and aluminum chloride. 2-Anthocyanins e.g. Karkadeh, color changes according to pH 3-Anthracene glycosides (anthraquinones): Laxative principle in Senna and Rhubarb. Anthraquinone glycosides  b- Cardiac glycosides Uses - Heart tonics (cardiotonics) - Treatment of cardiac arrhythmia - Diuretic effect due to increased renal circulation e.g. Digitalis leaves, Squill bulb and Strophanthus seeds Structure: a-steroidal nucleus b-lactone ring 5– membered ring ,Cardenolides, e.g. digitalis glycosides. 6 -membered ring, Bufadenolides , e.g. squill glycosides c- Deoxy sugar Cardiac glycosides (cont.)  Cardenolides Buffadienolides 5– membered ring 6 -membered ring e.g. digitalis glycosides e.g. squill glycosides  Chemical tests of cardiac glycosides: 1- Baljet’s test 2- Kedde’s for lactone ring test 3- Liberman’s- for steroidal Burchard test ring 4- Keller- for Deoxy- Killiani test sugar  c- Saponin Glycosides Steroidal saponin (C27) and triterpenoidal saponin (C30) Chemical Test: It produces persistent froth in water. It has hemolytic properties for R.B.Cs Biological activities, expectorant (licorice) and tonic (Ginseng)  d- Cyanogenic glycosides (Cyanophore glycosides) It yields HCN as a product of hydrolysis e.g. Amygdaline in Bitter almond. Linamarin in linseed.  e- Thiolglycosides (glucosinolates) e.g. Sinigrin in Black mustard Sinalbin in white mustard Glucosinolates Myrosinase Water Isothiocyanates + Thiocyanates + Nitriles + Glucose The hydrolysis products have 1.A marked chemoprotective activity (That protects patients from the toxic effects of anticancer drugs) 2.Goitre inducing activity. 3.Antimicrobial activity. 6- Antibiotics 7- Aflatoxins - Compounds synthesized -Mycotoxins developed by by certain molds and fungi mouldy grains -Having bacteriostatic -They are potent carcinogen, activity. teratogen e.g. penicillin e.g. aflatoxin  8- Vitamins -Organic compound necessary to the normal growth and maintenance of life in animals including human. -Isolated from plant or animal purified and concentrated for use as drugs e.g. (Ascorbic acid)  9-Hormones 10- Enzymes Active substances Organic bio-catalysts secreted by the endocrine produced by living cells. glands. They control the growth, They make most of the development and chemical reactions metabolism of the body in which make up life various ways. processes e.g. insulin e.g. amylase. Compare between each of the following: 1- volatile oil & fixed oil (4 points) 2- Cardiac glycosides & alkaloids ( chemical composition, occurrence, tests) 3- Thiolglycosides (glucosinolates) & Cyanogenic glycosides (Cyanophore glycosides) ( products of hydrolysis, examples) Faculty of Pharmacy