Resin

• Volatile oils resinify to form resins, which are products of oxidative metabolism of volatile oil.
• Resins are bitter, amorphous products with a complex chemical nature.
• Resins are complex mixtures of resin acid, resin alcohol, resinotannols, esters and resenes.
• Resins are solid or semi-solid, amorphous products derived from natural living sources and are mostly from the plant origin, with the exception of shellac which is obtained from the secretions of insects.
• Resins are secondary metabolites produced by higher plants and are nothing but oxidative products of terpenes.
• Resins are obtained as exudates from plants and are considered as end products of metabolism.
• Isoprene (C5H8) units are the fundamental building blocks of all true resins.
• Resins contain a large number of carbon atoms.
• Resins are non-crystallizable translucent masses.
• Resins soften and melt on heating.
• The specific gravity range of resins is from 0.9 to 1.25.
• DISTRIBUTION:

  n Resins are generally distributed in pants and rarely in the insects (e.g. Shellac)

  n They are present in the ducts or cavities known as schizolysigenous ducts
• 2 TYPES:

  1. Normal or Physiological resin

  l Resins that are preformed in the plants making injury to the plants can increase their yield (resin of Pinus)

  2. Abnormal or Pathological resin

  l Resins that are found in plants only when injury or incision is made (benzoin, Tolu balsam, colophony, aloe

  resins)

  OCCURENCE:

  Usually occur in different secretory zones or structures

  Examples:

  Resin cells - Ginger

  Schizogenous ducts or Schizolysigenous ducts or cavities - Pine wood

  Glandular hairs - Cannabis
• PATHOLIGICAL OR ABNORMAL RESINS: These types of resins are produced due to some kind of stress or damage caused to the plant. This type of resin production is also referred to as induced resin production.
• PHYSIOLIGICAL OR NORMAL RESINS: These types of resins are formed by normal metabolism of the plant without any external stimuli such as injury or infection. The formation of these resins occurs through the process of exudation which involves the rupture of special cells called resiniferous cells.
• CLASSIFICATION OF RESIN ACCORDING TO COMPOSITION ( RESIN COMBINATIONS):

  • Oleoresin – volatile oil + resin Eg. turpentine, capsicum, ginger, copaiba
  • Oleogumresin – volatile oil + gum + resin Eg. myrrh
  • Balsams – cinnamic acid or benzoic acid + resin Eg. storax, peru balsam, tolu balsam, benzoin
  • Glycoresins / glucoresins – glycosidal combination/sugar + resin Eg. Jalap and podophyllum
• Resin acid is a constituent of resin, combining the properties of carboxylic acids and phenols, and occurs both in the free state and as esters.
• Resinates are metallic salts of resin acids, some of which are used in soaps and varnishes.
• Resin alcohols include benzoresinol and storesinol, which do not give a tannin reaction with iron salts, and occur in free state and as esters in combination with simple aromatic acids.
• Resinotannols give a tannin reaction with iron salts, and are isolated from oleoresinotannol from peruresinotannol from the balsam of Peru, siaresinotannol and sumaresinotannol from benzoin, and storesinol from storax.
• Resinols, which do not give a tannin reaction with iron salts, are a type of resin alcohol that occur in free state and ester combination with simple aromatic acids such as benzoic acid, salicylic acid, cinnamic acid, and umbrellic acid.
• Resenes are complex natural substances devoid of characteristic chemical properties.
• Glycoresins are complex mixtures yielding sugars and complex resin acids on hydrolysis as the resin of jalap.
• DRUGS CONTAINING RESINS:

  1. Rosin (colophony) Botanical origin: Pinus palustris (Fam. Pinaceae) Use: Stiffening agent

  2. Podophyllum (mayapple mandrake, Devil’s apple) Botanical origin: Podophyllum peltatum AC: Podophyllin Use: Drastic purgative

  3.Eriodyctyon (Yerba santa) Botanical origin: Eriodyctyon californicum (Fam. Hydrophyllaceae) AC: Eriodictyol Uses: Stimulating expectorant, disguise quinine bitterness

  4. Jalap (jalap root) Botanical origin: Exogonium purga AC: jalap resin Use: hydragogue cathartic
• Mastic (Mastiche, Mastich) is a resin obtained from the Pistacia lentiscus tree, which belongs to the Anacardiaceae family.
• Mastic resin contains acids such as mastichic acid and B-resin (masticin).
• Mastic resin is used as a dental varnish to seal cavities.
• Kava (kava-kava) is a resin obtained from the Piper methysticum tree, which belongs to the Piperraceae family.
• Kava resin contains acids such as Yangonin, styryl pyrone, desmethoxyyangonin, kawain, dihydrokawain, methysticin, and dihydromethysticin.
• Kava resin is used as a central acting, skeletal muscle relaxant, antipyretic, local anesthetic, tranquilizer.
• Cannabis (Indian hemp, marihuana, pot) is a plant obtained from the Cannabis sativa tree, which belongs to the Moraceae family.
• Cannabis resin contains acids such as Hashish, THC, cannabinol, cannabidiol, cannabidiolic acid, cannabichromene, cannabigerol.
• THC (A9,tetrahydrocannabinol) is a psychoactive euphoria-inducing compound found in Cannabis resin.
• Cannabidiol is a non-psychoactive compound found in Cannabis resin that is used in the manufacture of rope.
• Capsicum or Cayene pepper is a source of oleoresin.
• African Chillies, siling labuyo, are a type of Capsicum frutescens.
• Louisiana long pepper, siling haba, is a type of Capsicum anuum var longum.
• Tobacco pepper, siling canoides, is a type of Capsicum anuum var canoides.
• Capsaicin is an active component of Capsicum or Cayene pepper.
• Capsaicin is used as a counterirritant, which causes irritation in the kidney, and as a teratogenic poison.