Lec - Resins

• Resins


  • Physically, are brittle, amorphous, hard transparent or translucent products
  • Solid or semisolid
  • Derived from plant sources (except Shellac – from insect secretion)
  • Products of volatile oil oxidation
  • Usually insoluble in petroleum spirit but dissolve more or less completely in alcohol, chloroform, and ether (organic solvents)
  • On heating they soften and finally melt
  • Some have pleasant odor and are used in perfumery (especially balsams)
  • Can be found as solo resins (ex. benzoin) or in combination with other constituents (resin combinations: resin acids, resin alcohols, resin phenols/resinotannols, oleoresins – turpentine, gum resins – copaiba resins, oleogum resins – myrrh, balsams – benzoic acid + cinnamic acid, glycoresins – under the family Convolvulaceae)
  • Contained in schizogenous or lysigenous ducts (resin ducts)
  • Can be found in other portions (ex. resin cells of bloodroot, heartwood of guaiacum, external glands of cannabis, internal glands of male fern, or glands of lac insect)
  • Yield is usually increased by injury (sometimes even, not produced until it has been injured)
  • Can be isolated by use of alcohol (ex. Jalap, podophyllotoxin), distillation (ex. copaiba, turpentine), or punctures (ex. mastic)
• Classification of resins


  • Resin acids
  • Resin alcohols
  • Resenes
  • Glycoresins
• Resins and resin combinations


  • Resins
  • Oleoresins
  • Gum Resins
  • Oleogum Resins
  • Balsams
  • Latex
• Resin acids


  • Contain oxyacids, and form metallic salts known as resinates
  • Soluble in aqueous solutions of alkalis
  • Used in soaps and varnishes
  • Examples: abietic acid in rosin, commiphoric acid in myrrh, and copaivic acid in copaiba
• Resin alcohols


  • Occur in free state and ester forms
  • Also known as resinols
  • Under this classification are resin phenols/resinotannols
  • When they exist with simple aromatic acids they form: benzoic, salicylic, cinnamic, umbellic acids – these are still under resin alcohols
  • Examples: aloeresinotannol (aloe), peruresinotannol and toluresinotannol (balsams) siaresinotannol and sumaresinotannol (benzoins)

  
• Resenes


  • Neutral, do not form salts
  • Complex, neutral substances that are devoid of chemical properties
  • Resist hydrolysis
• Glycoresins


  • Contain sugars (in combination with complex resins, particularly resin acids)
  • Example: jalap
• Rosin / Colophony


  • Abietic acid (80-90% constituent)
  • Before distillation, resin contains large amounts of (+) and (-) pimaric acids
  • During distillation, the (+)-pimaric acid stays as is but the (-) isomer becomes abietic acid
  • (-) pimaric acid responsible for abietic acid formation
  • Syltic acid - decomposition product of abietic acid

  
• Rosin / Colophony


  • Used for adhesive plasters, ointments, paper, adhesives, inks, rubber, linoleum, thermoplastic floor tiles and surface coating (industrial uses)
• Jalap


  • Constituents: Convolvulin, exogonic acid, ipurganol
  • Used as cathartic, hydragogue (cathartic effect but more liquid), and purgative
• Allied drugs similar to Jalap


  • Orizaba (Ipomoea orizabensis) – contains jalapinolic acid, orizabins
  • Sweet potato (Ipomoea batatas) – contains simonins
  • Scammony (Convolvulus scammonia) – contains scammonins
• Mayapple


  • Constituents: the lignan podophyllotoxin, peltatin (both alpha & beta form)
  • Peltatin is purgative
  • Podophyllotoxin is antimitotic for papillomas
  • The cis form of podophyllotoxin (picropodophyllin) is inactive
  • Derivatives in clinical use include etoposide and teniposide (active form of podophyllum)

  
• Mastic


  • Constituents: Pinenes (major constituent), camphene, masticin (beta form of resin), mastichic acid (alpha form of resin)
  • All of this are insoluble in alcohol
  • Used back then as breath sweetener by oriental women
  • Used as dental varnish to seal cavities
  • Protective agent for stomach
  • Microscopical mountant (as compound mastic paint) for samples to be fixed in microscopic evaluation

  
• Marijuana


  • Constituents: Cannabinols (most active form – THC : tetrahydrocannabinol)
  • THC is the one responsible for the psychoactive effect of marijuana
  • Drug type – THC-dominant, psychoactive
  • Hemp type – cannabidiol-dominant, used for ropes
  • Dronabinol – THC analog for treatment of nausea

  
• Yerba Santa


  • Constituents: Eriodictyol
  • Used to mask taste of bitter and disagreeable medicines (such as quinine)
  • American Indians smoked or chewed the leaves for asthma
• Lac


  • Constituents: Shellac (70–85% resin), laccaic acid (red color)
  • Used for varnishes, polishes, sealing wax, enteric tablet coating
• Kava-Kava


  • Constituents: Yangonin, kawain, methysticin
  • Used as skeletal muscle relaxant, tranquilizer, local anesthetic
• Guaiacum Resin


  • Constituents: Differentiated from rosin by the cupric acetate test, Guaiaretic acid
  • Used for chronic rheumatic conditions (used dried rhizome/roots)
• Ginger


  • Constituents: Gingerol, Zingerone, Shogaol
  • Pungency is due to gingerol
  • Zingerone is also pungent but with sweet odor
  • Shogaols – from loss of water from gingerols
  • Used as carminative and stimulant
  • Claims of controlling excessive and uncontrolled vomiting during first trimester of pregnancy
  • Potential anti-inflammatory, antiplatelet, antihypercholesterolemic, and antiulcer activities

  
• Piperaceae


  Constituents: Yangonin, kawain, methysticin
• Piperaceae


  • Skeletal muscle relaxant, tranquilizer, local anesthetic
  • It is available commercially
• Guaiacum resin


  • Source: Guaiacum officinale, G. sanctum
  • Family: Zygophyllaceae
  • Constituents: Differentiated from rosin by the cupric acetate test, Guaiaretic acid

  
• Guaiacum resin


  • Used for chronic rheumatic conditions (used dried rhizome/roots)
• Ginger


  • Source: Zingiber officinale
  • Family: Zingiberaceae
  • Constituents: Gingerol, Zingerone, Shogaol

  
• Ginger


  • Pungency is due to gingerol, which is destroyed by boiling with 2% KOH
  • Zingerone is also pungent but with sweet odor
  • Shogaols are from loss of water from gingerols
• Ginger


  • Carminative and stimulant
  • Claims of controlling excessive and uncontrolled vomiting during first trimester of pregnancy
  • Potential anti-inflammatory, antiplatelet, antihypercholesterolemic, and antiulcer activities
  • Commercially, it's known as Jamaican, African, or Cochin ginger
• Turpentine (Gum thus)


  • Source: Pinus palustris
  • Family: Pinaceae
  • Constituents: Coniferin

  
• Turpentine (Gum thus)


  • Counterirritant
• White pine (Gum thus)


  • Source: Pinus strobus (dried inner part)
  • Family: Pinaceae
  • Constituents: Coniferin
• White pine (Gum thus)


  • Expectorant
• Balsam of Copaiba


  • Source: Copaifera spp.
  • Family: Fabaceae
  • Constituents: Coniferin
• Balsam of Copaiba


  • Formerly urinary antiseptic, diuretic, expectorant, laxative
• Cayenne pepper


  • Source: Capsicum annuum
  • Family: Solanaceae
  • Constituents: Capsaicin (resinous component of capsicum, has aroma and spice)
• Cayenne pepper


  • Condiment, irritant, stimulant. Recently, anti-inflammatory as topical preparations. Used similarly as salonpas.
• Gamboge


  • Source: Garcinia hanburyi
  • Family: Clusiaceae
  • Synonyms: Gutta gamba - Hard brittle gum resin from garcinia
  • Constituents: Gambogic acid
• Gamboge


  • Pigment, purgative but is now little used in human medicine
  • Limited use for medicine, more on pigment uses
  • From orange to brown to bright yellow color
  • Used as varnish
• Myrrh


  • Source: Commiphora molmol
  • Family: Burseraceae
  • Synonyms: Guggai gum
  • Constituents: Contains a, b, y-commiphoric acids

  
• Myrrh


  • Ancient embalming material of Egyptians
  • Incense and perfume
  • Protective, stimulant, stomachic, used in mouthwash (Astring-o-sol)
  • Has local stimulant and antiseptic properties
• Frankincense


  • Source: Boswellia carterii
  • Family: Burseraceae
  • Synonyms: Olibanum
  • Constituents: Olibanol
• Frankincense


  • Incense, fumigation, used in China for treatment of leprosy