Section Introduction and Starches PDF

VIDEO LINK HTTPS://YOUTU.BE/LVS_HQVNIAK?SI=UPLY9R3TKHD OIZKH Two important links about parts of the microscope and how to use it: https://youtu.be/YjOdua47pFA?si=R7pBLwvgU0eLsawG https://youtu.be/2MsNTrBpw8A?si=9G1cXHVNJDl4srQj Introduction Pharmacognosy definiti...

VIDEO LINK HTTPS://YOUTU.BE/LVS_HQVNIAK?SI=UPLY9R3TKHD OIZKH Two important links about parts of the microscope and how to use it: https://youtu.be/YjOdua47pFA?si=R7pBLwvgU0eLsawG https://youtu.be/2MsNTrBpw8A?si=9G1cXHVNJDl4srQj Introduction Pharmacognosy definitions: The study of medicines derived from natural sources. The study of crude drugs either of plant, animal or semi synthetic origin. The word "Pharmacognosy" is derived from the Greek words pharmakon (drug), and gnosis (knowledge). N.B.: Crude drugs: drugs of plant, animal and microbial origin that contain natural substances that have undergone only processes of collection and drying. Pharmacognosy Lab. Requirements: 1- Lab Coat. 2- Pencil & Eraser. 3- Slides & Covers. 4- Student I.D. Optical Microscope  Dusting powders (fine powders) Starches Non-starches Starch  AMYLUM (Starch ,Amido ,Amidon & Stark) Starch is a polysaccharide carbohydrate consisting of a large number of glucose units joined together by glycosidic bonds. - General formula (C6H10O5)n. undefined Starch granules are polysaccharide in nature and composed of two main components: 1- Amylose: - 20% - water soluble - linear chain 2- Amylopectin: - 80% - water insoluble - branched chain Occurrence - It act as a reserve food material. - It occurs in granules of varying size in almost all organs of plants either alone or accompanied with other reserve food particles e.g., proteins. - It occurs in high amount in seeds, fruits, root and rhizomes than leaves and stems  Uses in pharmaceutics You have to take starch Used as skin emollient and nutrient Antidote of Iodine Poisoning Maize starch used as Used as tablet binder which helps in a lubricant for surgical tablet disintegration gloves. Properties of starch: 1- It is practically insoluble in cold water, but on boiling with water, it forms a white colloidal solution which forms jelly on cooling. 2- It is insoluble in alcohol and organic solvents. 3- It is hygroscopic and capable of absorbing up to 37% of moisture. 4- It is stable in the air and when heated up to 100 °C converted to dry. 5- On heating when dry at 150 °C – 160 °C it is converted to dextrin which is soluble in water. 6- It is stained blue with iodine, this colour disappear on heating and reappear on cooling. 7- On heating with chloral hydrate the granules gradually swell and finally burst and dissolve. 8- On phenol no destructive action appears but the granules becomes transparent and invisible. 9- On conc. H2SO4 charring of the granules due to removal of water from the starch granules. 10- It does not reduce Fehling’s solution, but on heating with dilute acids it is hydrolyzed giving glucose and other intermediates, which reduce Fehling’s solution. 11- Effect of moist heat: On heating starch granules in presence of water they first swell slowly then a small hole appears at the hilum, this hole increases in diameter and the granules swell up to many time its original size this process called gelatinization. Gelatinization of starch is also affected at room temperature by conc. acids, dil. alkali and saturated solution of heavy metals as CaCl2, ZnCl2. Macroscopical characters of starch: Starch occurs in irregular, angular masses or as a white powder, Maize starch is neutral but others show slight acidic or alkaline reaction to litmus paper. Starch is odourless and have characteristic taste. Types of Starches: Maize starch. wheat starch. Potato starch. Rice starch.  Potato Starch Concentric striations Eccentric hilum Semi-Comp. Compound Maize Starch Rice Starch Wheat Starch Take Care Air bubbles Drawing: