Resins, Combinations of Resins.


  • They cannot be defined clearly.

  • They can be described as mixtures of organic acids, alcohols, and esters.

  • Physical Properties:

  • They are amorphous, non- crystallizable, transparent, solids or semi-solids.

  • They are insoluble in water & soluble in organic solvents.

  • When heated they melt & burn with a sooty flame.

  • They are produced in plants in the special type of glands.

  • On boiling with alkalis they form resin soaps.

  • They are nonnitrogenous.

  • They are hard, heavier than water and nonconductive.

  • On trituration with water they form emulsion

Classification: -

  • According to the principal components present, they can be classified as follows:-

1 Acid Resin.Colophony, Myrrh.Abietic acid,

Commiphoric acid.
2. Ester Resin.Benzoin, Storax.Benzyl benzoate.

Benzyl cinnamate.
3. Resin alcohols.Balsam of Peru, GurjanbalsamPeruresinotannol, Gurjuresinol.

Resin Combinations: -

1) Oleoresins: -

  • Homogenous mixtures of volatile oils & resins are called as oleoresins.

  • e.g. Oleoresin of Ginger.

2) Oleo- gum- Resin: -

  • Homogenous mixtures of volatile oils, gums & resin.

  • e.g. Myrrh, Asafoetida.

3) Glyco resins: -

  • Homogenous mixtures of sugars & resins.

  • e.g. Jalap, Resin of Ipomoea

4) Balsams: -

  • If the resin contains cinnamic &/ or benzoic acid it is called as balsam.

  • e.g. Benzoin, Balsam of Tolu.

Isolation Of Resins: -

  1. By heating the crude drug. Ex. Guaiacum.

  2. By collecting the fossil resins. Ex. Kauri

  3. By making incisions on the plant. Ex. Asafoetida, Myrrh.

  4. By distillation. Ex. Colophony

  5. By extraction with alcohol. Ex. Oleoresin of Ginger & oleoresin of capsicum.

Chemical Tests:

A) Benzoin (Styrax benzoin Styraceae.)

1. Heat a small amount of benzoin slowly in a dry test tube -----> melts and white fumes are produced.

2.  Benzoin when heated with potassium permanganate solution -----> odor of benzaldehyde. (Sumatra benzoin)

3. Benzoin is extracted with alcohol and to the extract add water ------>milky white solution is formed.4. Digest benzoin with few drops of petroleum ether for 5

B) Asafoetida: (Ferula foetida Umbelliferae.)

  1. Powdered drug triturated with water –--> yellowish emulsion is produced.

  2. Combined umbelliferone test –The drug is boiled with HCL for 5 minutes, it is filtered and ammonia is added to the filtrate –----> A blue fluorescence is observed.

  3. The drug is treated with few drops of 50% HNO3 –---> green color is produced.

  4. The drug is treated with few drops of sulphuric acid – red color is produced which changes to violet on washing with water.

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