Untitled Quiz

Lipids

• Lipids are esters of long-chain fatty acids & alcohols (Lipoids/Lipins)
• General uses
  • Emollients (soften the skin)
  • Lubricant laxatives as emulsions
  • Solvents for IM injections
  • Manufacture of soaps (Saponification/Alkali-catalyzed esterification of FA = FA + KOH/NaOH)
  • Parenteral nutrient in TPN (highest caloric value = 9 kcal/g)

Classification of Lipids

• Fixed Oils:

  • Esters of FA + Glycerol
  • Also known as Triglycerides
  • Liquid at room temperature except for Myristica, Theobroma oil
  • Mainly unsaturated FA (pi-bonds)
  • Source: Plants
  • Function: Energy source

• Fats:

  • Esters of FA + High MW alcohol (Cetyl alcohol, Stearyl Alcohol)
  • Solid at room temperature except for Jojoba oil - Mainly saturated FA (sigma bonds)
  • Source: Animals
  • Function: Protection

• Waxes:

  • Solid or semi-solid except for Jojoba oil
  • Both saturated & unsaturated
  • Source: Plants & Animals

Reaction with Lipids

• Hydrogenation

  • Liquid oil → Solid fats
  • Addition of Water → breaks down to ALCOHOL + FATTY ACID
  • By passing H gas in presence of Nickel / Palladium through the oil heated @ 160-200C

• Heating:

  • Continuous heating of oil forms ACROLEIN/PROPENAL (presence of glycerol, formation of propenal)
  • Distinct odor of acrolein
  • Black markings in filter paper → confirm presence of acrolein

• Sulfation:

  • Sulfated / Sulfurated oils
  • Used as surfactants wherein temperature is kept down by chilling

• Oxidation:

  • Addition of Oxygen → Rancidity (fats become rancid/panis)

-Saponification: Formation of soap
- Fatty acid + Strong alkali - NaOH, Ca(OH)2 → hard soap - KOH → soft soap

USP Quantitative Tests for Lipids

• Acid Value / Number

  • no.of mg of KOH to NEUTRALIZE the free acids and to HYDROLYZE THE ESTERS in 1 g of the substance

• Ester Value

  • mg of KOH needed to SAPONIFY 1g of FA
  • DIFFERENCE between SV and AV (saponification value- acid value)
  • Ester Value Formula: EV = SV - AV

• Saponification Value

  • no.of mg of KOH needed to NEUTRALIZE the FREE ACIDS and SAPONIFY THE ESTERS in 1 g of the substance
  • Saponification Value Formula: SV = AV + EV

• Koettsdorfer number

  • no.of mg of KOH needed to NEUTRALIZE the FREE ACIDS and SAPONIFY THE ESTERS in 1 g of the substance

• Iodine Value

  • g of iodine absorbed under prescribed conditions by 100 g of sample
  • Measures the DEGREE OF UNSATURATION of the oil (↑ unsaturation, ↑ drying)
  • High iodine value oils partially resinify on exposure to air
    • Non-drying: < 100 (Olive oil, Peanut oil, Almond oil, Hazelnut oil, Cocoa butter, Palm oil, Fish oil, Tree oil)
    • Semi-drying: 100 - 120 (Cottonseed oil, Sesame oil, Corn oil, Soybean oil, Sunflower oil, Safflower oil, Mustard oil)
    • Drying: > 120 (Linseed / Flaxseed oil, Cod liver oil)

• Acetyl value

  • no.of mg of KOH required to NEUTRALIZE the ACETIC ACID freed by the hydrolysis of ACETYLATED fat or other substances

• Peroxide Value

  • no.of mg of ACTIVE OXYGEN per kilogram of a substance

Fatty Acids

• Saturated Fatty Acids
  • Monocarboxylic FA
  • Formic: Methanoic
  • Acetic: Ethanoic
  • Propionic: Propanoic
  • Butyric: Butanoic
  • Valeric: Pentanoic
  • CaprOic: Hexanoic
  • Enenthic: Heptanoic
  • CaprYlic: Octanoic
  • Pelargonic: nonanoic
  • CarprIc: Decanoic
  • Lauric: Dodecanoic
  • Myristic: Tetradecanoic
  • Palmitic : Hexadecanoic (Most abundant FA)
  • Stearic: Octadecanoic
  • Arachidic: eicosanoic
  • Behenic: Docosanoic
  • Lignoceric: Tetracosanoic
  • Cerotic: Hexacosanoic
• Unsaturated Fatty Acids
  • Lipid | Comments | Omega # | # of C / # of = | Δ Double Bond Position
  • ----------- | ----------- | ----------- | ----------- | -----------
  • Palmitoleic | | 7 | 16:1 | 9
  • Oleic | Cis – Oleic acid ; Trans – Elaidic acid | 9 | 18:1 | 9
  • Linoleic | Dietary precursor of PG (Vitamin F) | 6 | 18:2 | 9, 12 (Omega 6)
  • Linolenic | | 3 | 18:3 | 𝛼-9, 12, 15 (Omega 3) | 6 | 18:3 | 𝛾-6, 9, 12 (Omega 6)
  • Arachidonic | Immediate precursor of PG | 6 | 20:4 | 5, 8, 11, 14 (Omega 6)
  • Timnodonic | EPA (eicosapentanoic acid) | 3 | 20:5 | 5, 8, 11, 14, 17
  • Cervonic | DHA (docusahexaenoic acid) | 3 | 22:6 | 4, 7, 10, 13, 16, 19
  • Linolenic (Alpha : ↓ risk of heart disease, maintain normal heart rhythm and pumping)
  • Linolenic (Gamma: stimulate skin and hair growth, maintain bone health, regulate metabolism, and reproductive system)

Notable Fatty Acids

• Fatty Acids | Source | Use
• ----------- | ----------- | -----------
• Sodium morrhuate (morrhuic acid) | Atlantic cod, Gadus morhua | Sclerosing agent (varicose)
• Azelaic acid | Ozonolysis of castor oil (Ricinus communis) | Anti-Acne
• Undecyclinic acid | Pyrolysis of ricinoleic acid from castor oil | Anti-Fungal

Fixed Oils

• Castor Oil

  • Source: Ricinus communis
  • Origin: Tangan-tangan
  • Active Constituent: Triricinolein – converted to ricinoleic acid, Recinoleic acid - stimulant cathartic (laxative), Ricin - toxic principle, Recinine - alkaloid, Oleic acid – pharmaceutic aid

• Olive Oil / Oil of Europe / Sweet Oil

  • Source: Olea europea
  • Origin: First grade virgin (Less Pressure), Second gv (More Pressure), Technical grade (Hot Water), Sulfur grade (CS2 (Carbon Disulfide), Inferior Quality), Tournant oil (Fallen, decomposing fruits, High FA (stronger flavor, darker oil))
  • Active Constituent:

• Peanut oil / Arachis oil

  • Source: Arachis hypogea
  • Active Constituent: 75% Oleic acid, 25% Linoleic acid

• Sesame / Teel / Benne oil

  • Source: Linga Sesamum indicum
  • Active Constituent: Oleic acid, Linoleic acid

• Corn oil

  • Source: Zea mays
  • Active Constituent: Oleic acid, Linoleic acid

• Cottonseed oil

• Source: Gossypium hirsutum

  • Active Constituent: 0.6% Gossypol - Male Sterility, Lecithin - control deranged lipid metabolism

• Soybean oil

  • Source: Glycine soja
  • Active Constituent: Stigmasterol - precursor of steroid synthesis

• Almond oil

  • Source: Prunus amygdalus
  • Active Constituent: Polyunsaturated fixed oil
  • Apricot
  • Active Constituent: