Pharmacognosy I (PHBL 303) Lecture 2 Introduction to Pharmacognosy 1 (part 2) PDF

Faculty of Pharmacy and Biotechnology Pharmaceutical Biology Department Pharmacognosy I (PHBL 303) Winter 2023 Lecture 2 Introduction to Pharmacognosy 1 (part 2) Dr. Sara Thabit Sara.thabit@guc...

Faculty of Pharmacy and Biotechnology Pharmaceutical Biology Department Pharmacognosy I (PHBL 303) Winter 2023 Lecture 2 Introduction to Pharmacognosy 1 (part 2) Dr. Sara Thabit [email protected] Office: B5.132 Office hrs: Sunday 4th and Monday 2nd slots 1 Intended Learning Outcomes Domain 1: Fundamental Knowledge 1-1 Competency Key Elements 1-1-1 Describe the structure and function of the plant cells. 1-1-2 Articulate knowledge about the different types of plant tissues, and their functions. Domain 2: Professional & Ethical Practice 2-1 Competency Key Elements 2-1-1 Categorize plant species through describing uses 2-1-2 Relate the presence or absence of a certain plant features to the prevalent Environmental conditions. 2-2 Competency Key Elements 2-2-1 Identify the uses of each taxonomical group to which a plant belongs. Domain 3: Pharmaceutical Care 3-2 Competency Key Elements 3-2-1 Relate available information on taxonomical data to the potential presence of natural products. Domain 4: Personal Practice 4-1 Competency Key Elements 4-1-1 Develop the ability to think creatively and understand scientific principles. 4-2 Competency Key Elements 4-2-1 Communicate scientific information in a clear and concise manner both orally and Written. 4-3 Competency Key Elements 4-3-1 Practice independent learning required to build up knowledge base. 2  Origin of crude drugs Biological Geographical Botanical Zoological 3  Biological origin (Binomial system): Biological names of plants or animals from which we take the drug and family to which it belongs is very important to avoid any variation of the drug. Binomial system: is the nomenclature of the drugs, developed by Swedish scientist named Linnaeus. Bi = 2, Nomial = name This naming is based on dividing the plant name mainly to genus and species. 1- Genus or generic name: First part of plant name Should begin with capital letters. This is the plant’s group name. All plants having the same generic name are said to belong to the same GENUS. They all have similar characteristics and are more closely related to each other than any other genus. The plural of genus is GENERA. 4  Biological origin (Binomial system): Examples: Mentha: all mints (Mentha aquatica; Mentha arvensis; Mentha cervina; Mentha longifolia; Mentha piperita). 2- Species or specific name: The second part of the plant name is the specific name. Should begin with small letter. The species name is an ADJECTIVE that describes the genus. It often gives important descriptive information about the plant. There can be many different species in a particular genus. BOTH names should be underlined or written in italic. The binomial name of any plant can never be used to another plant. Taxonomy: is a branch of biology that deals with the naming and classification of organisms e.x: plants. 5 A plant taxonomist is the person who identifies and classifies plants. Biological origin (Binomial system): 6  Linnaeus vs Today Linnaeus grouped plants based on reproductive characteristics. Now we group plants based on phylogeny. Phylogeny=Evolutionary history, or how the plants are related. We use genetics to figure out how plants are related. In Linnaeus’s day, scientists did not know what evolution was or what DNA and genetics was. Taxonomy is not static, it is constantly being revised and 7 modified by each generation. Biological origin (Binomial system): The species name usually indicates: a) Pharmacological activity: e.x: Strychnos nux vomica (from two latin words, nut causing vomiting). Papaver somniferum (means hypnotic). Brayera anthelmentica (expelling worms). 8  Biological origin (Binomial system): The species name usually indicates: b) Characteristic color: Piper nigrum (black pepper) (nigrum means black) Digitalis purpurea (purple) Digitalis lanata (yellow) Nymphaea alba (white) Quercus rubra (red) 9 Biological origin (Binomial system): Biological names of plants could be based on: c) Geographical source: E.x: Cannabis indica is grown in India. d) General meaning: Atropa , from atropos meaning the name of the Greek fate that cuts the thread of life, indicating the poisonous characters of the drugs. 10  Biological origin (Binomial system): Biological names of plants could be based on: e) Morphological characters in the plant: E.x: Glycyrrhiza glabra (Liquorice) (glabrous=smooth). Hyoscyamus muticus (muticus=short). Begonia maculata 11  Biological origin (Binomial system): Biological names of plants could be based on: f) A plant character: E.x: An aromatic plant: - Myristica fragrans (nutmeg) (fragrans means nice aroma). - Caryophyllus aromaticus (clove) (aromaticus refers to aroma). 12  Biological origin (Binomial system): EXCEPTION: The species sometimes start with capital letter if is named after the person who discovered the plant or transported its seeds. e.x: Cinchona Ledgeriana. Charles Ledger 13 Biological origin (Binomial system): Related genera with similar flower parts are grouped together in Plant Families. Plant Family names often end in “aceae”. The Rose Family, Rosaceae, consists of apples, strawberries and plums because they all have similar flower structure. Why Use Scientific Names? It avoids confusion of common names which can be regional to an area of the world. It ensures exact identification for a specific plant type. Latin because it is a universal language and was used by early scholars to express plant names. Italics because it is conventional to italicize words and phrases that are expressed in a different language. 14 Hierarchical Classification: It starts very broad and gets more specific. 7 hierarchies in our system: Kingdom Very broad Phylum (Division) Class Order Family Genus Species Very specific An easy way to remember the classification levels: “King Philip Came Over From Great Spain” 15 Geographical origin: This is the habitat of the drug. It is the area where the plant or animal producing the drug is cultivated, collected or lives. It is important in plant identification because it is generally known that certain plants are grown in certain areas. Phytogeography or botanical geography: is the branch of biogeography that is concerned with the geographic distribution of plant species. Plants could be either: exotic or indigenous 16 Geographical origin: 1) An exotic plant: is a non-native (a plant introduced to a particular area in which it has never been found before, due to the intentional or accidental action of humans), the plant has the ability to adapt to a foreign environment and continue to spread. An exotic plant could be naturalized or invasive. Naturalized exotic plant: when an exotic plant manages to reproduce naturally in its new environment. N.B: Adjusting to the local environment allows a naturalized plant to continually reproduce and sustain its population without direct intervention from humans. Invasive exotic plant: a plant that spreads and alters the composition and structure of the natural ecosystems in which it spreads. 17 Geographical origin: 2) Indigenous (native) plant: Indigenous plants are those native to the specified locale. To qualify, the specimens in question must have been growing in that region for a considerable amount of time (longer than the plants that have merely naturalized in the region). Cotton is indigenous to America, naturalized in Egypt. G.R: The study of the habitat is important. A: it gives an indication of the characters of the soil, altitude and climatic conditions which affects the type and amount of active constituents. E.x: Cannabis sativa if grown in India: 1 m height, much resin and weak fibers. When grown in Italy large tree, strong fibers and no resin. 18 Duration of plant cycle: 19 Duration of plant cycle: Duration of plant cycle differs from plant to another and it could be: 1. Annual: plants that live, reproduce and die in one growing season. The length of growing seasons and period in which they take place vary according to geographical location, and may not correspond to the four traditional seasonal divisions of the year. E.x: Watermelon, tomatoes and corn 2. Biennial: plants that need two growing seasons to complete their life cycle, normally vegetative growth the first year (primary growth) and flowering the second year. E.x: Parsley and Carrots 20 Duration of plant cycle: 3. Perennial: plants that live more than two years. E.x: bananas and apples. Herbaceous: plants with shoot systems (leaves and stems). Herbaceous perennial: non-woody plants that live for more than two years. Woody perennial: plants that live more than two years, they create stiff structures above ground that they use throughout their lives. They may be divided into three groups: trees, shrubs and vines. E.x: Lavender 21 Duration of plant cycle: Monocarpic: plants that flower and make seeds only once then die. All annual and biennial plants are monocarpic and a few perennial. Polycarpic: plants that flower and set seeds many times before dying. 22 Types of plants: Ornamental plants: they are also referred to as garden plants. They have beauty as main trait. They are usually grown in the flower garden for the display of their flowers. Medicinal plants: plants which provide health-promoting characteristics, temporary relief from symptomatic problems or has curative properties based on some secondary metabolites as an active substance with biological activity. 23 Types of metabolites in plants: Metabolites: are the intermediate products produced during metabolism, catalyzed by various enzymes that occur naturally within cells. The term metabolites are usually used for small molecules. The various functions of metabolites include: fuel, structure, signaling, catalytic activity, defense and interactions with other organisms. The metabolites are produced by plants, humans and microbes. 24 Types of metabolites in plants: Primary metabolites: They are directly involved in the growth, development, and reproduction of organisms. They are key components in the maintenance of normal physiological functions in the body. They are often referred to as central metabolites. They are used as precursors for the synthesis of 2ry metabolites. They are distributed universally throughout the plant kingdom. 25 Types of metabolites in plants: Primary metabolites: 26 Types of metabolites in plants: Examples of primary metabolites: Carbohydrates They are hydrates of carbon, the most abundant class of organic compounds (sugars) found in living organisms with empirical formula CH2O. Proteins Polypeptide structures consisting of one or more long chains of amino acid residues having amine (amino acids) (NH2) and carboxyl (COOH) functional groups. Lipids Fatty, waxy, or oily compounds that are soluble in organic solvents and insoluble in polar solvents such as water. 27 Types of metabolites in plants: Secondary metabolites: They are small organic compounds produced through the modification of primary metabolites. They are formed near the stationary phase of growth. They do not play a role in growth, development, or reproduction. However, they play a role in ecological functions like defense mechanisms, aid in pollination, serve as antibiotics, and produce pigments. Some have no clear function. The lack of these compounds has little or no effects on the survival of the organism. They are different in every species and have restricted distribution. Volatile oils, phenolics, alkaloids, pigments, …..etc, are 28 some examples of secondary metabolites. Types of metabolites in plants: Examples of secondary metabolites: Volatile oils They are odorous volatile principles of plant and animal source, evaporate when exposed to air at ordinary temperature, and Hence known as volatile or ethereal oils. These represent essence of active constituents of the plant and hence also known as essential oils. Alkaloids Alkaloids is a term used collectively to describe a large and diverse group of chemicals that have alkali-like properties and at least one nitrogen atom in a heterocyclic ring structure. They have limited distribution and possess a significant physiological activity. 29 Types of metabolites in plants: Examples of secondary metabolites: Glycosides Glycosides are a class of compounds formed by linking sugars or sugar derivatives with another non-sugar species through the terminal carbon atoms of sugars. Polyphenols The term polyphenol is not well-defined, but is generally agreed that they are natural products "having a polyphenol structure (i.e., several hydroxyl groups on aromatic rings)" including four principal classes: "phenolic acids, flavonoids, stilbenes, and lignans. 30 Types of metabolites in plants: Examples of secondary metabolites: 31 Types of metabolites in plants: 32 33 34