Glycosides Lecture Notes PDF
Document Details
Uploaded by EndorsedVibrance
Faculty of Pharmacy, Cairo University
Wadah Jamal Ahmed
Tags
Summary
This document is lecture notes about glycosides covering introduction, extraction, and isolation protocols. The notes detail the process for obtaining glycosides from plant materials and the precautions to consider during the extraction process. It also includes details on other important considerations regarding extraction methods and procedures.
Full Transcript
Glycosides INTRODUCTION Wadah Jamal Ahmed Department of Pharmacognosy Introduction Extraction and Isolation Because of the wide range of physical and chemical properties of glycosides and other constituents associated with them, no common general method for their isol...
Glycosides INTRODUCTION Wadah Jamal Ahmed Department of Pharmacognosy Introduction Extraction and Isolation Because of the wide range of physical and chemical properties of glycosides and other constituents associated with them, no common general method for their isolation is recommended. Water, methanol, water-ethanol and ethanol are the most common solvents for extraction of glycosides. Precautions Before extraction 1-Deactivation of enzymes Drying the plant materials containing the Glycosides Carrying out the extraction at very low temp. 2- Maintenance of neutral conditions Neutral pH should be assured before and during extraction because: Acidity may result in hydrolysis. This is overcome by addition of Alkali like CaCO3. Mild alkalinity may sometimes produce racemization. 3- Defatting of fat-rich organs (e.g. seeds) before extraction: High amounts of lipophilic compounds hinder glycoside extraction. Defatting is usually carried with petroleum ether
