PCOG MODULE 2

• Brief history of Pharmacognosy:

  • Babylonians made clay models
  • Egyptians conducted preliminary studies of plants for embalming and mummification
  • Hindus developed ayurveda, the "science of life" and "mother of all healing arts"
  • Greeks: Pedanios Dioscorides wrote "De Materia Medica" on 600 plants including aloe, belladonna, colchicum, digitalis, ergot, and opium
  • Claudius Galen introduced "Galenical Pharmacy"
  • Germans: C. A. Seydler coined the term pharmacognosy in "Analectica Pharmacognostica" (1815)
  • J.A. Schmidt first used "pharmacognosy" in "Lehrbuch der Materia Medica" (1811)
• • Others like Fluckiger provided a comprehensive definition of pharmacognosy
• Terms to remember in Pharmacognosy:

  • Natural Substances: directly obtained from plants and animals in nature
  • Synthetic: made in the lab through total synthesis or semi-synthesis
  • Crude Drugs: vegetable or animal drugs collected and dried
  • Extractives/Derivatives: chief principles of crude drugs separated for specific use
  • Menstruum: technical term for solvent
  • Indigenous Plant: plants growing in their native country
  • Naturalized Plant: plants growing in a foreign land
  • Chief Principle Solvents: used for different types of extracts
• Methods of Extraction:

  • Maceration: solid ingredients soaked in solvent for at least 3 days
  • Digestion: maceration with gentle heat
  • Percolation: slow passage of solvent through a column of the drug
  • Decoction: boiling in water for 15 minutes
  • Infusion: maceration in cold or hot water
• Preparation of Crude Drugs:

  • Collection: best time to collect based on the plant part
  • Harvesting: use of mechanical devices for large-scale collection
  • Drying: process to prevent microbial growth and enzymatic degradation
  • Curing: special drying process to enhance properties
  • Garbling: final step to remove extraneous materials
  • Packaging, Storage, Preservation: methods for protecting and marketability
• Classification of Drugs:

  • Morphologic: based on the plant part used
  • Taxonomic: based on natural relationship or phylogeny
  • Pharmacologic/Therapeutic: based on therapeutic effect
  • Chemical: preferred method for classification
• Carbohydrates in Pharmacognosy:

  • Monosaccharides: building blocks that can be hydrolyzed to simple sugars
  • Disaccharides: two monosaccharide units linked by a glycosidic bond
  • Oligosaccharides: 3-10 monosaccharide units
  • Polysaccharides: more than 10 monosaccharides
  • Examples of monosaccharides: ribose, xylose, glucose, fructose, galactose
• Hexose (6C) - Most Important Sugar:

  • Glucose: abundant form in nature, used as a nutrient
  • Fructose: sweetest monosaccharide, used in infant feeding formula
  • Galactose: brain sugar, found in milk and neuronal fibers
• Glucose is present in the human blood in the amount of 60 to 90 mg in 100 mL blood
• Sucrose is a disaccharide composed of glucose and fructose linked by β, 1-2 glucosidic bonds
• Maltose is a disaccharide composed of two glucose molecules linked by β, 1-4 glucosidic bonds
• Lactose is a disaccharide composed of galactose and glucose linked by β, 1-4 glucosidic bonds
• Lactulose is a disaccharide composed of galactose and fructose linked by 1-4 glucosidic bonds
• Maltose is a reducing sugar and lactose is a non-reducing sugar
• Sucrose is the only disaccharide that occurs free in nature and is a non-reducing sugar
• Inulin is obtained from the cell sap of the underground organs of plants in the family Compositae
• Chitin is a homoglycan of N-acetylglucosamine and is the exoskeleton of mollusks, arthropods, and fungi
• All monosaccharides are reducing sugars, while all disaccharides are non-reducing sugars except for maltose and lactose
• Glycogen is a storage polysaccharide in animals, more branched than starch, and is stored in the liver and skeletal muscles
• Hyaluronic acid is found in vitreous humor and synovial fluids, while chondroitin sulfate is found in cartilage, tendons, and ligaments
• All GAGs are sulfated except for hyaluronic acid, and all GAGs contain uronic acid except for keratan sulfate
• Chondroitin sulfate is a sulfated glycosaminoglycan that provides resistance to compression in cartilage
• Hyaluronic acid is a non-sulfated glycosaminoglycan distributed widely throughout connective, epithelial, and neural tissues
• Proteoglycans are heavily glycosylated proteins consisting of a core protein covalently bonded with glycosaminoglycan chains
• Glycolipids are carbohydrates attached to lipids associated with cell membranes, while glycoproteins are small proteins with smaller polysaccharide chains that stabilize membrane structure
• Hunter syndrome is deficient in a-L-iduronidase enzyme, while Scheie syndrome is deficient in iduronate-2-sulfatase enzyme
• Hurler syndrome is deficient in iduronate-2-sulfatase enzyme, and San Filippo syndrome is deficient in heparan sulfatase enzyme
• Maroteaux syndrome is deficient in B-galactosidase enzyme, and Sly syndrome is deficient in B-glucuronidase enzyme
• Natowicks syndrome is deficient in hyaluronidase enzyme
• Mucopolysaccharidosis is a group of diseases related to deficiencies in various enzymes
• Compounds metabolically related to carbohydrates
• Oxidation of aldoses:

  • Glucose's aldehyde group leads to aldonic
  • Glucose's terminal alcohol group leads to uronic acid
  • Glucose's aldehyde and terminal group lead to aldaric
• Products of oxidative metabolism of carbohydrates
• • Lactic acid is responsible for dental caries and produced during vigorous exercise (lactate)
  • Lactic acid's IUPAC name: 2-hydroxypropanoic
• Cherry juice:

  • From fresh ripe cherry fruits (Prunus cerasi)
  • Contains 1% malic acid
  • Used to prepare cherry syrup
  • Malic acid's IUPAC name: 2-hydroxybutanedioic acid
  • Citric acid is efflorescent and an antidote for sodium hydroxide poisoning
  • Tricarboxylic acid discovered from lemon juice by Scheele
  • Tricarboxylic acid's IUPAC name: 2-hydropropane-1,2,3-tricarboxylic acid
  • Tartaric acid is a dicarboxylic acid and a byproduct of the wine industry
  • Tartaric acid's IUPAC name: 2,3-hydroxy-butanedoic acid
• Products of reductive metabolism of carbohydrates
• Mannitol:

  • IV (osmotic diuretic) and PO (laxative)
  • Used to treat increased intracranial pressure
  • From manna, dried saccharine exudate of Fraxinus ornus
  • Sorbitol/Glucitol:
  • Used as a plasticizer in soft gelatin capsules
  • Accumulates in the body and cleanses the eyes (cataract)
  • Approximately half as sweet as sucrose and a humectant
  • From the berries of mountain ash, Sorbus aucuparia
• Fehlings–Nylander’s Monosaccharides:

  • Maltose
  • Lactose
  • Osazone/Kowarsky: Mannose (the only sugar that forms readily insoluble osazone crystals)
  • Glucose, fructose, and mannose form broom-like/fan-like crystals
  • Sucrose and maltose form sunflower-like crystals
  • Lactose forms cotton ball crystals
  • Tollen’s Phloroglucinol Test: test for pentoses
  • Only non-pentose sugar that tests positive: cellobiose
• Identifying tests for reducing sugars:

  • Fehling’s test: brick red ppt
  • Barfoed’s test: fast production of red ppt
  • Mucic acid test: soluble
  • Tollen’s test
  • Benedict’s Test
  • Seliwanoff’s test: cherry red solution
• Check Point:

  • Glucose is also known as the physiologic sugar
  • Kumyss is fermented milk
  • False statement: Sorbitol is twice as sweet as sucrose