Page 31 - phytochemistry I - PharmD Clinical

Resin and Resin Combinations

Resins are oxidation products of the terpenes present in volatile oils.
They are complex in nature but free from nitrogen.

They are solids or semisolid substances, insoluble in water but
soluble in organic solvents. On heating, they soften, melt and burn with
smoky flame.

• Formed in special passages or tubes called resin ducts. Ducts anastomose
so a single incision can drain the resin from considerable area of the plant.

 Natural Resins: Produced by plants either normally or pathologically in the form of

exudation e.g. Mastic.

Prepared Resins: The alcoholic plant extract is concentrated and poured into excess

water so resins precipitated, collected and dried e.g. Podophyllum resin.

Synthetic Resins: are condensation products of chemicals like phenol prepared

synthetically.

Formation of Resins:
- Oleoresin cells….. as in Ginger.
- Whole Tissue……. as in Guaiacum wood. Resin is present in all cells.
- Ducts …………….. as in Umbelliferous Fruits.
- Glands …………… which may be: Internal as in Filix mass or External as in
Cannabis.

• Chemically, they are very complex of substances of different
chemical constituents:

1. Neutral inert compounds (Resenes).
2. Resin acid: carboxylic acid group containing resinous substances e.g.

abietic acid (colophony) & commiphoric acid (myrrh)
3. Resin ester: esters of resin acids or the other aromatic acids like

benzoic, cinnamic, salicylic acid etc. e.g. benzoin

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