Lec 1 Introduction to Pharmacognosy 2020-2021 PDF

Lec 1 Introduction to Pharmacognosy Lecturer Dr. Thukaa Zuhair Abdul-Jalil 2020-2021 1 Introduction Pharmacognosy is the study of the physical, chemical, biochemical and biological properties of drugs, drug substances of natural origin as well as the search for new drugs from natural sources (e.g. p...

Lec 1 Introduction to Pharmacognosy Lecturer Dr. Thukaa Zuhair Abdul-Jalil 2020-2021 1 Introduction Pharmacognosy is the study of the physical, chemical, biochemical and biological properties of drugs, drug substances of natural origin as well as the search for new drugs from natural sources (e.g. plants and animal kingdoms). The term comes from two Greek words: Pharma from "pharmakon" meaning drug or medicine, and cognosy derived from "gnosis" meaning knowledge. 2 1 4 Pharmacognosy Pharmaceutics Natural Dose of drug 3 Pharmacology and toxocology Animal study 2 Chemistry Synthetic 5 Biochemistry drug study inside human body 6 Clinical Pharmacy Therapeutic effects 3 Pharmacognosy Science Concerned with Studying the Following Subjects: 1) 2) 3) 4) Taxonomy of natural sources of drugs (plants, animals and micro-organisms). 5) 6) The biosynthesis of the active constituents. 7) 8) 9) Collection & Storage of the part used. Distribution of natural products in the world. Description of plants such as: Tree (Salix) ,Shrub (Catharanthus) ,herbals (Peppermint). The active constituents from natural sources ( Active groups ) like : ( Glycosides , Alkaloids , Volatile Oils , Tannins , etc. ). The part used in medicine and pharmacy as : Leaf ( Mint , Digitalis ) , Roots ( Liquorice) , Seeds ( Coffee bean ) , Bark ( Cinnamon ). Physical, Chemical & Biological properties of the scribed for a limited duration active constituents. The Correct prescription of natural drug in the treatment of the diseases. 4 Plant Names & Botanical Latin Binomial nomenclature: Carl von Linne a.k.a. Linnaeus , Swedish botanist and explorer, came up with a system for naming in 1753 where each species of plant has a name which has two parts. This is called Binomial nomenclature. Each of two parts of the name used Latin forms. 1. The first word is the name of the Genus , It's usually in Italics and starts with a upper case (capital letter). 2. The second word is the name of the species. This is usually lower case and also expressed in italics. 3. OR write the both (genus and species) by underlined words. 4. Then write the plant Family, with capital letter. Coffee ‫القهوة العربية‬ Botanical name: Coffea arabica OR Coffea arabica (Family name: Rubiacae). 5  Binomial nomenclature: ( botanical name) by Swedish botanist , Linnaeus. The first word is the name of the Genus. ( Italic and with capital letter ) The second word is the name of the species. ( Italic and with small letter) Atropa belladonna OR write the both (genus and species) by underlined words. Atropa belladonna Then write the plant Family, with capital letter. Solanaceae 6 Definitions & Basic Principles in Pharmacognosy 1. Drug: is a natural or synthetic substance used in the treatment, cure, prevention, or diagnosis of disease. 2. Natural substance: this term refers to those substances that are found in nature (plants and animals). They have not change in their molecular structure when they exposed to some processes like drying, crushing, grinding and evaporating. 3. Crude drugs: are drugs originated from plants, animal kingdom, minerals. They contain more amount of active constituent. 7 4. Phytochemistry: a branch of chemistry dealing with the chemical processes associated with plant life & the chemical compounds produced by plants (chemistry of plants, plant processes and plant products). 5. Chemotaxonomy: as the method of biological classification based on similarities and differences in the biochemical compositions of organisms (originally plant). 8 7. Pharmacopoeia: is a book containing directions for the identification of samples and the preparation of compound medicines and publishing by the authority of a government or medical or pharmaceutical society. Pharmacopoeias are: a. BP (British Pharmacopoeia). b. USP (United States pharmacopoeia). c. Ph. Eur. (European pharmacopoeia). 8. Official drugs : natural or synthetic drug that recognized and included by official pharmacopeia. Ex: The juice or extract of unripe fruit of poppy plants (Papaver sp.) and its active constituents as (Morphine) used as narcotic. 9 9. Unofficial drugs : These drugs are natural, or synthetic, that are included in the official Pharmacopoeia , but they are not found in the current issues , because those drugs by the time are being have toxic effects. Ex: Khat plant which used in Yamane country as a narcotic. 10. Non – official drugs: such kind of drugs are never appear in official pharmacopoeia. 10 11. Indigenous plants: are plants which grown in original or native countries. 12. Naturalized plants: are plants which grown in a location or region other than their original countries. 13. Cultivated plants: are plants which grown in locations or regions other than their original countries, they grow by man under controlled conditions in order to improve their quality & quantity of drugs production. 14. Wild plants: that plants have grown in wild with very little or no help from human. 11 15. Extraction: method of obtaining the active components found in plants. Extraction removes only those substances that can be dissolved in the liquids (single or mixture) which are referred as solvents or menstrums. Undissolved portion of the plant that remains after the extraction processes is completed called marc. Solvent used after extraction is called extract and the product of the extraction process is known as extractive. 16. Extract: Is a substance made by extracting a part of a raw material, often by using a solvent such as Ethanol or Water. 17. Extractives: the principle constituents of natural substance which give natural drug its pharmacological activities, these found as single or mixtures and used as therapeutic agents, for example: Caffeine alkaloid is extracted from leaves of tea plants. As shown in the next slide 12 Tea pot Extraction Water (solvent or menstrum) Extractives Tea leaves (plant) Principle constituents of natural substance. Source of heat Ex: Caffeine alkaloid. Marc (Undissolved plant material without active components) Extract 13 14