Pharmacognosy Lecture Notes PDF, Fall 2024-2025

Pharmacognosy- I PG 101 and CPG 101 Fall 2024-2025 BY Amani Moukhtar Marzouk Professor of Pharmacognosy and ntural products chemistry Mansoura University Lecture 1  Pharmacognosy: 1- is the science of nature...

Pharmacognosy- I PG 101 and CPG 101 Fall 2024-2025 BY Amani Moukhtar Marzouk Professor of Pharmacognosy and ntural products chemistry Mansoura University Lecture 1  Pharmacognosy: 1- is the science of nature-derived medicines, pharmaceuticals and poisons. 2- The American society of pharmacognosy defines it as the study of the physical, chemical, biochemical and biological properties of drugs of natural origin as well as the search for new drugs from natural sources. Phytotherapy is the use of plants and plant extracts for therapeutic purposes. It is also referred to as medical herbalism  PLANT ANATOMY Plant anatomy describes the structure and organization of plant cells, tissues and organs in relation Organs Tissues to their development and function. i.e it is the study of plant cell and tissue structure. Plant Cell Cell Structure & Function Cell Theory: All living organisms are made up of cells. Cells are the smallest working units of all living organism. i.e. A cell is the smallest unit that is capable of performing life functions.  “TYPICAL” PLANT CELL 3 2 1 http://waynesword.palomar.edu/images/plant3.gif  PLANT CELL PARTS Each cell consists of living and non living materials. Plant cell has three parts 1- The cell wall (Non living) 2- The protoplast (Living) 3- The vacuoles ( (Non living) on living)  1- Cell wall Is semi-rigid, not selectively permeable, non-living. Present in plant cell but absent in most animal cells. It gives protection and support, covering the living plasma membrane beneath it. Cell wall is distinguished into three parts: Made of calcium pectate the cell Aligned from outside to inside 1- Middle Lamella 2- The primary cell wall 3- The secondary cell wall  Cell wall 1- Middle Lamella Inside It is the first partition arises cell 2 between two cells. (considered as the Inside cell 1 cementing material of cells).  It is made up mostly of Inside a cell Inside the adjacent calcium and magnesium cell pectate. 2- The primary cell wall Is thin and characteristic of young, growing cells. It consists mainly of cellulose molecules. It is capable of extension as the cell grows. 3- The secondary cell wall Is thicker and stronger, and it is deposited when most cell enlargement has ended (in old organs). It consists mainly of cellulose, hemicellulose, lignin and suberin. The secondary wall differs from the primary walls in that it is incapable of increase in area.  PITS AND PLASMODESMATA Most cells have thin areas in the primary walls which Walls of two have small pores through adjacent which strands of cytoplasm Vacuole plant cells (plasmodesmata) connect Plasmodesmata the protoplasm of one cell with that of the adjacent Layers of one plant cell. cell wall Cytoplasm Plasmodesmata aid in the Plasma membrane movement of materials and transmit stimuli between adjacent cells. Pits: characteristic of secondary walls A pit is a region in the cell wall in which no secondary wall material is deposited i.e areas without lignification. Walls showing pits are called pitted walls There are three types of pits: 1- Simple 2- bordered 3- Half bordered 2- Protoplast: Living component of cell The protoplast, consists of the plasma membrane and all components inside it, except any non-living materials as crystals, starch grains and contents of the vacuoles. The protoplast is surrounded by a delicate membrane (the plasma membrane) and includes two major components (the cytoplasm and the nucleus). A- The plasma membrane Is a phospholipid bilayer. It basically looks like a phospholipid sandwich with the heads forming the bread and the tails forming the meat in the middle. Function of plasma membrane: Controls the permeability and diffusion of different substances in and out of the cell. B- The cytoplasm Clear, gelatinous fluid inside the cell which suspends and holds other cell’s organelles: 1- The Endoplasmic reticulum 2- Ribosomes 3- Golgi complex 4- Mitochondria 5- Plastids (Leucoplasts, Chromoplasts, Chloroplasts) 6- Lysosomes 7- Nucleus: The nucleus controls all the activities of the cell and the transmission of hereditary characters.  Plastids Leucoplasts Chromoplasts Chloroplasts nonpigmented plastids some of lack chlorophyll but synthesize contain chlorophyll the sites of which synthesize starch or oils or and retain carotenoid pigments photosynthesis, the conversion of proteins which are responsible for the light energy to chemical energy. Upon exposure to light they may yellow, orange or red colours of develop into chloroplasts many flowers, old leaves, some fruits and some roots Vacuoles Mature cells of the plants have vacuoles which may enlarge to much an extent that the cytoplasm becomes located adjacent to the cell walls as a thin film. The vacuoles are filled with cell sap. It is surrounded by lipoprotein membrane. The vacuole may contain pigments as anthocyanin e.g. Coloured petals or contain other ergastic substances. ERGASTIC SUBSTANCES The materials present in the vacuoles are known as ergastic substances. They are nonliving components of the cell. They are either reserve substances that may be utilized by the protoplast for vital activities, or they are by-products of metabolism (waste products). Ergastic substances can be classified as: a- Carbohydrates (e g. starch) b- Protein c- Mineral Crystals  1- CARBOHYDRATES Usually in the form of grains, commonly shows Starch layering (striations) of amylose & amylopectin around a point ‘hilum’ Individual grins composed of layers deposited around a point called hilum which may be 1) simple starch grain centric or eccentric. is made up of two or more individual grains 2) semi- compound surrounded by a zone of a common enveloping grain layer. consists of an aggregate of individual grains without 3) compound grain common enveloping layers.  Striations Maize Starch Potato Eccentric Starch hilum Semi Centric hilum compound (simple starch grain) Compound grain Rice starch  2- PROTEINS Proteins are stored either as amorphous masses or crystalline structures called aleurone grains. Aleurone grain is solid rounded body enclosing a large crystal like structure called crystalloid (protein in nature) and a small rounded body called globoid (mineral body of double phosphate of calcium and magnesium). 3- Mineral Crystals Inorganic deposits in plants mostly of calcium oxalate or carbonate 1) calcium oxalate 2) Calcium carbonate Within an enlarged epidermal cell a small cellulosic outgrowth of the cell arises and becomes impregnated with calcium carbonate clusters known as (cystolith). FATS: Ester of fatty acids with glycerol They are widely found in the plant body A) Lipids or fatty matter may be oil (liquid) or fats (solid) B) Wax, suberin and cutin are fatty in nature. They act as protective substances in and on the cell wall.