carbohydrates

• Carbohydrates serve as a primary source of energy for the body.
• Carbohydrates are aldehyde or ketone alcohols containing carbon, hydrogen, and oxygen (CHO) in which the hydrogen and oxygen are generally in the same ratio as in water
• First product formed in photosynthesis
• Classification of Carbohydrates:

  • Sugars or saccharides:
  • Monosaccharides: compounds that cannot be hydrolyzed to simple sugars
  • Disaccharides: yields 2 monosaccharide molecules on hydrolysis
  • Trisaccharides and so on...
  • Polysaccharides: starch, cellulose
• Related compounds:

  • Starch yields glucose and is known as glucosan
  • Inulin yields fructose and is known as fructosan
  • Cellulose: a polysaccharide composed of glucose units joined by β-1,4 linkages, forms the primary cell walls in plants
• Structure of monosaccharides
• Classification of Monosaccharides:

  • Hexoses: most important monosaccharides found in plants, first detectable sugars synthesized by plants
  • Pentoses: products resulting from the hydrolysis of pentosans, result from the hydrolysis of gums and mucilages
  • Example: Xylan, which occurs in the wood of deciduous trees
• • Production: controlled enzymatic hydrolysis of starch
• Disaccharides:

  • Sucrose = glucose + fructose, also known as saccharum or sugar, non-reducing sugar
  • Sources: Saccharum officinarum (Sugar Cane), Beta vulgaris (Beet), Acer saccharum (Sugar maple)
  • Pharmaceutical Uses: necessary for syrups, demulcent, nutrient, flavorant, preservative
  • Production: obtained by crushing stems, boiling with lime, filtering, decolorizing, concentrating, and crystallizing
  • Dextrose = α-D-glucopyranose, D-glucose, blood glucose, sugar naturally occurring in grapes and other fruits
  • Pharmaceutical Uses: nutrient, flavorant, tonicity agent
• Dextrose Excipient:

  • A crystalline dextrose monohydrate used as an agent of pharmaceutic necessity
  • Dextrates: purified mixture of saccharides (not less than 93% dextrose), used as sweetening agents, tablet binders, coating agents
  • Production: controlled enzymatic hydrolysis of starch
• Dextrose Excipient:

  • Liquid glucose: obtained by incomplete hydrolysis of starch, used in candy, beverages, ice cream, baking products, and canning industry
• Fructose = D-fructose, levulose, fruit sugar

  • Colorless or yellowish, thick, syrupy liquid that tastes sweet
  • Source: sweet fruits, honey
  • Uses: food for diabetic people, ingredient in infant feeding formulas, electrolyte replenisher
  • Production: obtained by inversion of aqueous solutions of sucrose
• Lactose = milk sugar, glucose + galactose, found in cow's milk

  • Source: whey, Bos taurus
  • Uses: tablet diluent, nutrient in infant's food, establishes intestinal microflora
• Lactulose:

  • A semisynthetic sugar prepared by alkaline rearrangement of lactose
  • Mechanism of action: metabolized by bacteria in the colon to acetic and lactic acids, causing a laxative effect
• Xylose = Wood sugar

  • Source: corn cobs, straw, or similar materials
  • Use: diagnostic agent to evaluate intestinal absorption
  • Production: boiling of plant source to hydrolyze xylan polymer
• Caramel:

  • Burnt sugar obtained by heating sugar or glucose until sweet taste is destroyed and a dark brown mass appears
  • Uses: coloring and flavorant in pharmaceutical preparations
• Plant Acids:

  • Lactic acid: acidulant, electrolyte replenisher
  • Citric acid: buffer, acidulant in effervescent preparations
  • Fumaric acid: hematinic
  • Tartaric acid: effervescent formulations
• Alcohol or ethanol:

  • Product of natural fermentation process
  • Most abused drug substance in the world
  • Uses: local anti-infective, caloric source of fluid replenishment
• Sugar Alcohols:

  • Dulcitol: slightly sweet tastant for human taste cells
  • Mannitol: osmotic diuretic and laxative, diagnostic agent for urine flow
  • Sorbitol: humectant, non-caloric sweetener, osmotic laxative
• Gums and mucilages are natural plant hydrocolloids that are anionic or nonionic polysaccharides or salts of polysaccharides
• Upon hydrolysis, they produce: Arabinose, Galactose, Glucose, Mannose, Xylose, and Uronic acids
• Sources of gums and mucilages include:

  • Shrubs or Tree exudates: acacia, karaya, tragacanth
  • Marine gums: agar, algin, carrageenan
  • Seed gums: locust bean, psyllium
  • Plant extracts: pectins
  • Starch and Cellulose derivatives: hetastarch
  • Microbial gums: dextrans
• Tragacanth Gum:

  • Name: Gum Tragacanth
  • Source: Exudates from Astragalus gummifer
  • Use: Suspending agent for insoluble powders, emulsifying agent for oils and resins, adhesive
• Acacia:

  • Name: Gum Arabic, Egyptian Gum
  • Contains: arabin, complex mixture of calcium, magnesium and potassium salts of Arabic acid
  • Source: Exudates from Acacia senegal
  • Use: Suspending agent, demulcent and emollient, adhesive and binder in tablet granulations, emulsifier
• Ghatti gum:

  • Name: Indian gum
  • Readily forms dispersion with cold water
  • Indigenous to Sri Lanka and India
  • Substitute for acacia
• Karaya gum:

  • Name: Sterculia Gum
  • Components: D-galacturonic acid, D-glucuronic acid residues
  • Genus: Sterculia
  • Source: Sterculia villosa
  • Use: Bulk laxative, emulsifying, suspending agent, dental adhesive, used in wave set solutions and skin lotions
• Sodium alginate:

  • Source: Macrocystis pyrifera (brown seaweed)
  • Use: Suspending agent, suspending for cosmetics, tablets binder and thickening agent
• Agar:

  • Derivative: algin
  • Component: agarose and agaropectin
  • Source: Gelidium cartilagineum, Gracilaaria confervoides
  • Use: Laxative, suspending agent, emulsifier, gelating agent for suppositories, tablet disintegrant, culture media
• Carrageenan:

  • Also known as Irish moss or Chondrus
  • Types: Kappa and Iota (good gelling agents), Lambda (thickener)
  • Source: Red algae and seaweeds Chondrus crispus, Gigartina mamillosa
  • Use: Stabilizer for emulsions and suspensions, bulk laxative
• Furcellaran:

  • Name: Danish agar
  • Source: Red algae
  • Use: Gelating agent, suspending agent
• Guar gum:

  • Name: Guaran
  • Contains galactomannan
  • Source: Cyamopsis tetragonolobus
  • Use: Bulk-forming laxative, thickener, tablet binder, disintegrant
• Locust Bean Gum:

  • Contains galactomannan
  • Source: Carob (flour), Carob pulp or St. John’s bread Ceratonia siliqua
  • Use: Thickener, stabilizer
• Xanthan gum:

  • Source: Xanthomas campestris
  • Use: Emulsifying agent, suspending agent, spreading agent in toothpaste preparations
• Pectin:

  • General term for group of polysaccharides present in the primary cell walls of all seed-bearing plants
  • Source: Citrus peel or apple pomace
  • Use: Emulsifying agent, suspending agent, protectant, antidiarrheal formulation, enhance physiologic function in digestive tract
• Angiosperms are divided into two types: Angiosperms (Magnoliophyta) and Gymnosperms
• Angiosperms are "fruit-bearing" plants and are a major source of plant-derived drugs
• Gymnosperms have "naked seeds" that are not enclosed in carpels and have "needle" leaves
• Majority of botanical drugs are derived from leaves and aerial parts of Angiosperms
• Angiosperms:

  <|>Alliaceae (Monocotyledoneae):

  <|>Genus: Allium is known for its sulfur-containing compounds like alliin and allicin
• Allium sativum (Garlic) is used as an antibiotic, for hypertension, arteriosclerosis, and stroke