PHARMACOGNOSY CARBOHYDRATES

Chapter 1: Introduction

• Monosaccharides: Galactose is identified as a less sweet sugar compared to glucose and fructose, with the same molecular formula (C6H12O6).

  • Sources of Galactose: Found primarily in dairy products, sugar beets, and various gums and mucilages.

  • Components: It is a component of lactose, oligosaccharides, ribosides, gangliosides, glycolipids, and glycoproteins.

  • Etymology: The name 'galactose' comes from Greek, meaning 'milk sugar'.

  • Chemical Structure: Galactose is an aldose (6 carbon atom sugar) and an epimer of glucose, differing by the position of one hydroxyl group.

  • Isomers: Galactose occurs in both D and L forms, where L is typically found in plants.

• Lactose: This disaccharide consists of one glucose molecule and one galactose molecule, primarily found in milk.

• Galactokinase: Enzyme that phosphorylates galactose using ATP to produce galactose-1-phosphate, which is then converted into glucose-1-phosphate.

• Fructose: Another monosaccharide with the same formula (C6H12O6), found in honey and sweet fruits.

  • Names: Known as fruit sugar, D-fructose, and levulose.

  • Absorption: It is absorbed during digestion but not as rapidly as glucose or galactose.

  • Sources: Honey, flowers, berries, root vegetables, sugarcane, corn, and sugar beets.

  • Uses: Enhances the sweetness of food and drinks, used for browning in baked goods.

• Disaccharides: Composed of two monosaccharides and are formed through dehydration reactions (loss of water).

  • Common Disaccharides: Sucrose, lactose, and maltose.

  • Glycosidic Bond: A covalent bond that joins carbohydrate molecules.

Chapter 2: Glucose And Galactose

• Disaccharides:

  • Sucrose: Known as table sugar, a combination of glucose and fructose linked by an alpha 1-2 glycosidic bond. Found in green plants.

  • Lactose: Milk sugar made of glucose and galactose (alpha 1-4 link). Source: mammal milk.

  • Maltose: Malt sugar composed of two glucose units linked by an alpha 1-4 bond.

  • Sources of Sucrose: Sugarcane, sugar beets, and sugar maple (Acer saccharum).

  • Pharmaceutical Uses: Sucrose serves as a base for syrups and acts as a nutrient and preservative.

• Lactose Properties: Found in cow's milk and characterized by the production of butter and buttermilk during standard separation processes.

  • Fermentation: Lactic and butyric acid fermentation are involved in lactose processing.

• Maltose Properties: Produced via starch breakdown, used in germinating seeds.

Chapter 3: Alcohol And Dextrose

• Plant Acids:

  • Citric Acid: Derived from lemons and used as a buffering agent; it is a tricarboxylic acid.

  • Lactic Acid: Synthesized or obtained through sugar fermentation; used in infant formula.

  • Tartaric Acid: A byproduct of winemaking, useful in buffer systems as a dicarboxylic acid.

• Alcohols:

  • Ethanol: Local anti-injection use; 70% alcohol solutions for intravenous feeding.

  • Mannitol: Laxative, diabetic aid, and osmotic diuretic obtained through mannose reduction.

  • Sorbitol: Sugar alcohol used in food production and as a sweetener in various products.

Chapter 4: Galactose And Glucose

• Oligosaccharides: Include galacto-oligosaccharides formed from lactose, containing 2 to 8 galactose units.

  • Human Milk Oligosaccharides (HMOs): Found in breast milk and important for infant nutrition.

  • Plant Sources: Chicory root, Jerusalem artichokes, onion, legumes, and wheat.

• Polysaccharides: Consist of long chains of monosaccharides; can be homopolysaccharides or heteropolysaccharides.

  • Examples: Starch, inulin, dextran, and cellulose.

  • Starch Uses: Reserve food material in plants, used in food products, and as a thickening agent.

Chapter 5: Note Of Cellulose

• Purified Cotton: Used in surgical dressings and textile manufacturing.

• Gums:

  • Classification: Natural thickeners, can be anionic or non-anionic polysaccharides.

  • Uses: Emulsifying agents, tablet binders, and bulk laxatives.

  • Sources: Exudates from trees (e.g., acacia), marine-derived gums (e.g., agar), and seed gums (e.g., guar).

Chapter 6: Conclusion

• Caraginan: Derived from red seaweeds, used for gel formation and stabilizing emulsions.

• Plantago Seed: Contains polysaccharides, used as bulk laxatives.

• Pectins: Found in citrus fruits and apples, used as gelling agents and stabilizers in food.