logging in or signing up Pharmacognosy Lecture # 1 (Glycosides) [By, Sir Tanveer Khan] URASS Download Post to : URL : Related Presentations : Let's Connect Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Copy embed code: Embed: Flash iPad Dynamic Copy Does not support media & animations Automatically changes to Flash or non-Flash embed WordPress Embed Customize Embed URL: Copy Thumbnail: Copy The presentation is successfully added In Your Favorites. Views: 1928 Category: Education License: All Rights Reserved Like it (0) Dislike it (0) Added: September 29, 2011 This Presentation is Public Favorites: 1 Presentation Description Study of Glycosides according to Pharmacognosy. Lecture delivered by Muhammad Tanveer Khan to Batch:01093 (F09) in The University of Lahore, Pakistan. Comments Posting comment... Premium member Presentation Transcript Glycosides : Glycosides Muhammad Tanveer Khan Introduction : Introduction A glycoside is an organic compound, usually of plant origin, that is composed of a sugar portion linked to a non-sugar moiety. Sugar portion ……….. Glycone Non-sugar portion…... Aglycone / Genin Linkage between sugar and non-sugar is usually an “oxygen linkage” Types : Types Based on atoms involved in glycosidic linkage O- glycosides C- glycosides S- glycosides N- glycosides Types : Types According to Sugar moiety Glucosides Ribosides Rhamnosides Classification : Classification (a) Cardioactive glycosides: Digitalis, Strophanthus and white squill (b) Anthraquinone glycosides: Cascara, Aloe, Rhubarb, Cochineal and Senna (c) Saponin glycosides: Glycyrrhiza, Sarsaparilla (d) Cyanophore glycosides: Wild cherry (e) Isothiocyanate glycosides: Black Mustard (f) Lactone glycosides: Cantharide (g) Aldehyde glycosides: Vanilla (h) Miscellaneous glycosides: Gentian, Quassia, Dioscorea Cardioactive Glycosides : Cardioactive Glycosides Used in treatment of CHF Mechanism: These glycosides; Increase the force of systolic contraction Shorten length of systole As a result Heart have more time to rest between contraction. Therapeutic activity depends upon; 1. Chemical nature of aglycone 2. Number of sugars Slide 8: Aglycone is steroidal. Aglycone may be; Cardenolide (5-membered lactone at place of R) Bufanolide (6-membered lactone at place of R) a) Digitalis : a) Digitalis Botanical Origin: Digitalis purpurea Digitalis lanata Family: Plantigenaceae Part used: Dried leaves Collection: Leaves collected from 2nd year growth of plant in June before opening of flower. Drying is done by applying artificial heat (temperature not more than 65°C). Slide 10: Chemistry: Four aglycons in Digitalis Digitoxigenin Gitoxigenin Gitatoxigenin Digoxigenin (only in Digitalis lanata) b) Strophanthus : b) Strophanthus Botanical Origin: Strophanthus kombe Strophanthus hispidus Family: Apocynaceae Part used: Dried ripe seeds Collection: Fruits are collected when fully ripen i.e. in June and July Slide 14: Chemistry: Active constituent is Strophanthin. Upon hydrolysis it yields; Strophanthidin Sugars (alpha D-glucose + beta D-glucose + beta D-cymarose) Apart from Strophanthin, there are; 30% fixed oils Resin / Mucilage Nitrogenous bases ( Trigonellin, Choline ) Slide 15: Uses: Cardiac stimulant Diuretic c) White squill : c) White squill Botanical Origin: Urginea maritima Family: Liliaceae Part used: Dried fleshy scales of bulb Collection: Bulbs are collected in August. Outer scale is removed and inner scale is divided into pieces and dried in sunlight. Slide 17: Chemistry: Active constituent is Scillaren. Upon hydrolysis it yields; Scillarenin Sugars (1 molecule of glucose + 1 molecule of rhamnose) Slide 18: Uses: Emetic Expectorant Cardiac tonic Diuretic You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.