Expt. 6

• Alcohol

  • molecule containing the hydroxyl group that is bonded to the carbon atom of an alkyl or substituted alkyl
• Hydroxyl group contributes to the physical properties of alcohols
• General formula of Alcohol: R-OH
• Classification of Alcohols

  • Primary Alcohol
  • Secondary Alcohol
  • Tertiary Alcohol
• Primary Alcohol

  • Carbon atom of the OH group is attached to only one / single alkyl group
• Secondary Alcohol

  • Carbon atom of the OH group is attached to two alkyl groups on either side
• Tertiary Alcohol

  • OH group is attached to the carbon atom which is connected to three alkyl groups.
• Water - 0 Carbons
• Primary (1º) Alcohol - 1 carbon directly attached
• Secondary (2º) Alcohol - 2 carbons directly attached
• Tertiary (3º) Alcohol - 3 carbons directly attached
• Properties of Alcohol

  • Color - Colorless
  • Physical State - Liquid
  • Odor - Fruity odor
  • Solubility with water - soluble (due to the presence of hydrogen in hydroxyl group)
• Alcohol

  • most widely used
• Alcohol

  • kills bacteria, fungi, but not endospores or naked viruses
• Alcohol

  • used to mechanically wipe microbes off skin before injections of blood drawing
• Alcohol

  • one of the best solvent
• Alcohol can be used as disinfectant and antiseptic
• Alcohol are fungisital (kills fungi)
• SAR means Structure Activity Relationship
• Structure Activity Relationship indicates that the activity of a molecule is based on its structure.
• Structure Activity Relationship

  • Increase of #C = Increase of antimicrobial property (but only until the 8th C)
• Structure Activity Relationship

  • Increase in primary chain length = increase in VDW = increase of ability to penetrate microbial membranes
• Structure Activity Relationship

  • Increase in branching = decrease in VDW = decrease in antimicrobial property
• In USP, alcohol is known as ethanol (ethyl alcohol, wine spirit)
• Alcohol, USP

  • clear, colorless, volatile liquid with a burning taste and a characteristic pleasant odor
• Alcohol, USP

  • flammable, miscible with water in all proportions, and soluble in most organic solvents
• Alcohol, USP

  • Commercial ethanol contains approximately 95% ethanol by volume
• Rubbing alcohol

  • usually contains 70% ethanol
• Rubbing alcohol is used as

  • astringent (forms precipitate)
  • rubefacient (redness to skin)
  • mild local anesthetic (for wounds)
• Dehydrated alcohol

  • absolute alcohol
• Dehydrated alcohol

  • contains not less than 99% w/w of ethanol
• Dehydrated alcohol

  • preparation
• Dehydrated alcohol

  • very high affinity for water and must be stored in tightly sealed containers
• Dehydrated alcohol

  • used as chemical reagent or solvent
• Dehydrated alcohol

  • has no water (99%)
• Isopropyl alcohol

  • primarily used as disinfectant for the skin and for surgical instruments
• Isopropyl alcohol

  • rapidly bactericidal in the concentration range of 50% to 95%
• Isopropyl alcohol

  • 40% concentration is considered equal in antiseptic efficacy to a 60% ethanol in water solution
• Adverse Drug Reaction

  • Nausea
  • Vomiting
  • Vasodilatory Flushing (redness)
  • Antidote (when exposed to methanol)
• Adverse Drug Reaction

  Ethanol —> (alcohol dehydrogenase) —> Acetaldehyde —> (aldehyde dehydrogenase) —> Acetate